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Author Topic: Stalker Stunt Engines  (Read 20608 times)

Offline Ruslan Kurenkov

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Stalker Stunt Engines
« on: December 29, 2018, 02:55:52 PM »
Hello, friends !
Congratulations on your upcoming New Year!
I want to wish you all a good mood and a lot of good flights in 2019.
Controllineparts will do its best to ensure that your flights on our lines and engines are successful and bring you only positive emotions.
I want to invite you to discuss all questions about the use of different Stalker stunt engines in this particular special topic.
I want to invite you to ask here any questions on the selection of the stunt engine for your aircraft, on the technical parameters and installation sizes of various Stalker engines, on installing the correct propeller size on your engine and on the fuel composition, on using the correct type of glow plugs and providing spare parts.
I will be happy to answer all your questions and will gladly take part in the discussion of all issues related to the repair and maintenance of the stunt engine Stalker.
Today we have in stock more than 10 Stalker, varying in size and location of the engine muffler, from the smallest 0.40 to the most powerful 0.81. I think that such a wide range of stunt engines will be able to satisfy both the novice and professional pilot. We also provide full technical support to our customers and the provision of any spare parts for our engines.

Regards
Ruslan Kurenkov

Offline Dennis Saydak

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Re: Stalker Stunt Engines
« Reply #1 on: December 29, 2018, 04:03:52 PM »
Hello RK and best wishes for the new year. Can you provide any information on the long stroke .61 version. Does anyone use it?
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Offline Randy Cuberly

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Re: Stalker Stunt Engines
« Reply #2 on: December 29, 2018, 04:17:36 PM »
Ruslan,

I have a Stalker 66LS but have so far only run it on the bench.  It seems to be very easy to start and mild mannered.  I am close to finishing an airplane for it but have a question regarding using a tuned pipe with it.

The engine will be used in a GeoXL airplane that is approximately 700 Sq/inch wing area but will be relatively light at approximately 57 ounces.   I have built two of these airplanes in the past so I'm relatively sure of that weight.   

I have used tuned pipes for many years now and like the control that they provide, especially in the wind!

What is your opinion of trying to use a tuned pipe with this engine and  can you provide a header that would function with a tuned pipe?

Thanks,

Randy Cuberly

 


 
Randy Cuberly
Tucson, AZ

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #3 on: December 29, 2018, 04:50:46 PM »
Hello RK and best wishes for the new year. Can you provide any information on the long stroke .61 version. Does anyone use it?
Hello Dennis!
The long-stroke version of the Stalker 0.61 engine was developed and produced more than 10 years ago. The engine received the designation LT-LS, in contrast to the previous modification LT-EX where the piston diameter was 24 mm and the piston stroke was 22 mm. The piston diameter in the engine Stalker 61 LT-LS is 23 mm and the piston stroke is 24mm. This modification is the most successful and sold than the short-run classic version. On the basis of the Stalker 61 LT-LS engine, the best-selling Stalker company was created - a modification with the number 66, with a diameter and stroke of 24 mm and the designation LT-LS. You can see all the dimensions of the engine in the attachment, they fully coincide with the 66 LT-LS, these engines have a common crankcase.
Australian athletes fly successfully on these engines, perhaps they will share their experience with you.

Regard
Ruslan Kurenkov

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #4 on: December 29, 2018, 05:23:14 PM »
Ruslan,

I have a Stalker 66LS but have so far only run it on the bench.  It seems to be very easy to start and mild mannered.  I am close to finishing an airplane for it but have a question regarding using a tuned pipe with it.

The engine will be used in a GeoXL airplane that is approximately 700 Sq/inch wing area but will be relatively light at approximately 57 ounces.   I have built two of these airplanes in the past so I'm relatively sure of that weight.   

I have used tuned pipes for many years now and like the control that they provide, especially in the wind!

What is your opinion of trying to use a tuned pipe with this engine and  can you provide a header that would function with a tuned pipe?

Thanks,

Randy Cuberly

 


 

Hi Randy!
I am very glad to hear you.
I used to fly a lot of Stalker 66 with my friend, now two juniors are flying for a few years flying next to Stalker 66. The weather at our workouts is almost always very windy and if a plane weighs less than 60 ounces then no wind is terrible for him. My plane after two repairs scored from 64 ounces to 66 ounces. At the same time, I calmly flew in a very strong wind on my Stalker 66 on thin lines 0.0145 and a wooden two-bladed propeller 13.8/6.3 in (350mm / 160mm)
Initially, this engine was designed by Oleg for operation without the use of a resonant tube and without the use of nitromethane in fuel. Maybe someone used a pipe with this engine but we have not conducted such experiments. I do not know whether it will work with the pipe or not, but I am almost sure that it will not.
It is a pity, but I did not have the opportunity to fly on an airplane with an engine with a resonant tube, and I don’t understand absolutely anything in the resonant tubes. To use the resonant tube, Stalker manufactures the K-77 engine (a copy of the PA-75 engine) for Kaz Minato. On these engines at the World Championships in Landres, members of the USA and Japan national teams flew. They are very fond of resonant tubes.

Regards
Ruslan

Offline Randy Cuberly

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Re: Stalker Stunt Engines
« Reply #5 on: December 29, 2018, 06:07:14 PM »
Hi Ruslan,

Thanks for your reply.  I'm very familiar with the K77 engine you make for Kaz Minato.  I bought one of the first ones that He received from Stalker.  It's a tremendous powerplant.  Perhaps even a little better than the PA 75 (of which I have two).  It's perhaps just a bit less powerful than the PA but it regulates the best in wind of any engine I've flown.
Based on what you've told me I'll probably just use the Stalker 66 with the supplied muffler.

Do you supply a rear mounting ring or rubber device for supporting the muffler, or is it OK to just let it hang from the engine.  That seems a bit risky for the muffler mount of the engine to just allow it to hang on the engine.  I would think vibration would take it's toll on that very quickly.

I would very much appreciate any information you can supply for mounting the muffler!

Thanks for any help you can provide.

Randy Cuberly



Randy Cuberly
Tucson, AZ

Offline Michael Palm

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Re: Stalker Stunt Engines
« Reply #6 on: December 29, 2018, 06:14:36 PM »
I have a flying buddie that used a pipe on a Stalker 61. He said that the engine is very wide in operation style. Maybe the 66 is like. I dont remember how the set up was. He is not on this forum i think, but he is on facebook and write some time in the control line enthusiast group. His name is Kauko Kainulainen, he is a Finn living in Sweden but he speaks good English. Maybe you can write him there and ask.
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Offline Steve Helmick

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Re: Stalker Stunt Engines
« Reply #7 on: December 29, 2018, 11:42:06 PM »
Hi Ruslan,


Do you supply a rear mounting ring or rubber device for supporting the muffler, or is it OK to just let it hang from the engine.  That seems a bit risky for the muffler mount of the engine to just allow it to hang on the engine.  I would think vibration would take it's toll on that very quickly.

I would very much appreciate any information you can supply for mounting the muffler!

Thanks for any help you can provide.

Randy Cuberly


I have a .76RE and two .51RE's. There is a cast-in "boss" on the back of the mufflers that are supposed to be supported...the exact method escapes me at the moment, but I believe it would fit in a neoprene grommet which could be mounted in a piece of plywood or CF plate.  :) Steve
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Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #8 on: December 30, 2018, 03:59:04 AM »
Hi Ruslan,

Thanks for your reply.  I'm very familiar with the K77 engine you make for Kaz Minato.  I bought one of the first ones that He received from Stalker.  It's a tremendous powerplant.  Perhaps even a little better than the PA 75 (of which I have two).  It's perhaps just a bit less powerful than the PA but it regulates the best in wind of any engine I've flown.
Based on what you've told me I'll probably just use the Stalker 66 with the supplied muffler.

Do you supply a rear mounting ring or rubber device for supporting the muffler, or is it OK to just let it hang from the engine.  That seems a bit risky for the muffler mount of the engine to just allow it to hang on the engine.  I would think vibration would take it's toll on that very quickly.

I would very much appreciate any information you can supply for mounting the muffler!

Thanks for any help you can provide.

Randy Cuberly




Hi Randy!
Thank you for your question. I often have to answer it in correspondence with customers.
The silencer on the engine Stalker is attached to the crankcase with two M3 bolts for an internal hex. Three years ago, our supplier of bolts let us down a little. He sold us a batch of bolts that were very hardened and brittle. After 50-70 flights, one of the two mounting bolts of the muffler necessarily collapsed from constant thermal expansion. After that, we started to pack all our engines with M3 stainless steel bolts only. This steel is not brittle and does not collapse like black hardened bolts. You must replace your black bolts with stainless steel bolts. Between the engine crankcase and muffler housing, apply a thin layer of automotive sealant to repair the engine. The sealant layer should be no more than the thickness of the lines (0.015 inch). You must firmly hold the mounting bolts of the muffler immediately after applying the sealant and be sure to put on the bolt a little blue thread retainer. The silencer on the Stalker 66 is fixed only with two M3 bolts and that's it. The silencer is not attached to the body of the aircraft through a rubber ring as on the Stalker 40. This engine has virtually no vibration. It is perfectly balanced if you use a well-balanced propeller and spiner.
Regards,Ruslan


I have a .76RE and two .51RE's. There is a cast-in "boss" on the back of the mufflers that are supposed to be supported...the exact method escapes me at the moment, but I believe it would fit in a neoprene grommet which could be mounted in a piece of plywood or CF plate.  :) Steve
Hi Steve !
Thank you for your question. Stalker 76 engines have a silencer mount with only two M3 bolts as I described above for Randy Cuberly.
Engine Stalker 51 has a silencer mount on the thread on which it is screwed to the engine crankcase and tightened with a locking nut. Before connecting to the crankcase, a little automotive sealant should be applied to the thread to repair the engine and then fasten immediately.
Rubber ring to the body of the aircraft is attached only the smallest Stalker 40.

Regards,Ruslan

Offline Chuck_Smith

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Re: Stalker Stunt Engines
« Reply #9 on: December 30, 2018, 04:46:10 AM »
Good looking stuff. You can definitely see the family resemblance to the K77. The .76 appears to share a lot of the same parts with the K77 such as the venturi, head, thrust washer, etc.

I'm a bit skeptical of the fuel consumption. You're saying the .76  can go six minutes on 100 milliliters? That's less than 3 1/2 ounces. My K77's sure won't do that! They're thirsty beasts on a pipe and I need a little over 8 ounces for a flight.

Still, good stuff and prices look good too. I may have to buy a couple to try them.

Thanks!


Chuck
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Offline Don Jenkins

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Re: Stalker Stunt Engines
« Reply #10 on: December 30, 2018, 07:28:13 AM »
I built a 64 ounce plane around a Stalker .61 LT-EX.  I got one flip starts, 7 minute runs on 3.75 ounces of 5% nitro with 20% lube (50/50), and a Xoar 13-5 prop.  It pulled great on 64 foot lines and I never had a problem with it until I put into the asphalt, yes destroyed.  However, I purchased a Stalker .66 and I plan on building another Vertigo, but I'll name it something else.  All in all a great engine, and it sounds great too!

Don

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Re: Stalker Stunt Engines
« Reply #11 on: December 30, 2018, 08:50:13 AM »
Ruslan-
I had thought that there was a .55 in the line up before?

Kind Regards,
Target
Regards,
Chris
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Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #12 on: December 30, 2018, 11:58:38 AM »
Good looking stuff. You can definitely see the family resemblance to the K77. The .76 appears to share a lot of the same parts with the K77 such as the venturi, head, thrust washer, etc.

I'm a bit skeptical of the fuel consumption. You're saying the .76  can go six minutes on 100 milliliters? That's less than 3 1/2 ounces. My K77's sure won't do that! They're thirsty beasts on a pipe and I need a little over 8 ounces for a flight.

Still, good stuff and prices look good too. I may have to buy a couple to try them.

Thanks!


Chuck

Hello Chuck
Thanks for the nice review about my store.
Stalker engines operate at very low revolutions from 7000 to 9000 revolutions per minute with large-diameter propellers. They have a very high torque for this. That is why such a low fuel consumption per flight. It is like a diesel engine in cars. Diesel is denser than gasoline. Methanol fuel for engines Stalker is also denser than the fuel with nitromethane that you use on your K77. This all greatly affects fuel consumption. The work of the motors Stalker is a pronounced 4-2-4 mode in which 70 percent of the engine's operating time is mode 4. For many years of operation, we learned how to adjust our Stalkers and select the propeller pitch so that during horizontal flight the engine works only in mode 4 and This speed of flight in a circle of 5.2-5.3 seconds. When flying at this speed on lines 63-65 feet, the whole complex of flight figures takes 5 minutes and 15 seconds from start-up and at least 6 more laps until the engine stops. A total of 5 minutes and 45 seconds of engine running time per 100ml (less than 4 ounces) of fuel is obtained. Fuel tanks are designed for a full refill of 120 ml of fuel (4.5 ounces). Before starting, we take 15-20 ml of fuel from the fuel tank. Such a small amount of fuel is very easy to place in an aircraft with small fuselage sizes. And at the end of the flight, such a small amount of fuel does not change the location of the center of gravity of the model aircraft and slightly changes the handling. A large amount of fuel for your K77 greatly changes the center of gravity back to the end of the flight and the two intertwining eights at the end of the complex you will perform on a completely different handling plane than a double coup at the beginning of the complex when your tank is full.
Regards,Ruslan

Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #13 on: December 30, 2018, 01:30:12 PM »
I'm a bit skeptical of the fuel consumption. You're saying the .76  can go six minutes on 100 milliliters? That's less than 3 1/2 ounces.

    In addition to the factors mentioned - it's also generating *much less* shaft HP in level flight, because the propellors you have to use at 8000-ish rpm are much more efficient than those you have on a PA75. You might be getting 30-40% efficiency in level flight with a 13-3.75 at around 11,500, and maybe 50-60% with a 13-6.5 at 8800 or so. That's around half the shaft power for the same airplane speed. Less power = less fuel, add to that some optimization for this range of operating conditions, higher specific output from getting rid of some of the nitro and replacing it with more methanol, and I can easily believe it. Just running it hotter will greatly increase the amount of power released per unit fuel volume, so reduce the fuel consumption.

   You see the same thing on electrics. The governor-type electrics can run almost any prop you want, just dial in the RPM you need. Start with 6" of pitch, and you may wind up with 30% of your battery capacity left. Change to 3.5" of the same type, spin it up much faster to get the same lap time, and you may be down at 5% of your battery left, or less.

     Look at 4-strokes, they are down in this area in similar conditions, and have a slight improvement in the scavenging and run at nearly optimal mixture ratio (much hotter), with similar high-pitch props and it's 3 1/2 ounces or less, even with 20% nitro.

    You are counting on this very low efficiency in normal flight for the PA or other similar system (which can use up to about 8.5 ounces when you set it up like David's), the system absolutely requires it in order to maintain the speed in corners. As the airplane slows down, the propellor efficiency greatly increases, inhibiting the speed loss, and additionally, driving the pipe closer to resonance, causing the torque to go up as the increased prop load slows the engine down. Same thing if you speed up (like from whip-up), the efficiency drops drastically, at least causing no additional speed increase, if not trying to help slow you down. At the 2003 NATs, in the 30 mph wind, my PA sounded like it was 16-stroking at the bottom of the maneuvers, it was so unloaded (far less than static) to the point I thought it was going to quit.   Unfortunately it did the same thing coming around upwind, for the same reason...

     Point being that for competitive systems, particularly large ones, you are running them in terribly inefficient ways - dead rich/low temperature/low amount of energy released per unit fuel volume, extremely inefficient propellors, with reduced fuel energy density. And frequently, running gigantic engines on relatively small airplanes where you have to figure out how to get rid of huge amounts of excess power. David Fitzgerald's airplane is *smaller than a Thunderbird* and he is running it on a piped 75 - you better do something to make it very inefficient! Fly the same airplane with a 40VF, it will probably fly just about as well, and set up the way we started out, you might be running as little a 4.5 ounces (like I was doing with a similar airplane as recently as the 98 NATs), and that is with 10% nitro and a very inefficient prop.

   So I wouldn't dispute that this could be done on even less fuel with a more efficient prop and higher specific energy fuel, in fact, it seems like about right to me and about what I would expect. I will reserve judgement on the relative in-flight performance and ability to get scores in a stunt contest in the year 2019, but I think we already did very similar experiment to end up where we have.

     Brett

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #14 on: December 30, 2018, 02:16:08 PM »
I built a 64 ounce plane around a Stalker .61 LT-EX.  I got one flip starts, 7 minute runs on 3.75 ounces of 5% nitro with 20% lube (50/50), and a Xoar 13-5 prop.  It pulled great on 64 foot lines and I never had a problem with it until I put into the asphalt, yes destroyed.  However, I purchased a Stalker .66 and I plan on building another Vertigo, but I'll name it something else.  All in all a great engine, and it sounds great too!

Don

Hello Don
You build very beautiful airplanes. I liked the one in the photo. It is a pity that you crashed your plane. It is a pity that the engine was also destroyed. You had one of the first engines Stalker. With the engine 61 LT-EX began the history of the company Stalker 15 years ago. Now in the production company Stalker 11 different engines. The stalker 66 that you purchased to replace the 61st engine is a very good choice. Crankcase dimensions are exactly the same and weight too. Only the propeller will need a little more. Not 330-340 mm in diameter, but 350 mm., And the screw pitch is not 150 mm and 160 mm.
The flight time you wrote it is actually exactly like that. For Stalker 61 fuel tank per 100 ml is enough for 7 minutes of work. For Stalker 66 this volume is enough for 6 minutes 30 seconds.
You wrote that you use fuel with 20 percent lubricant. This is a lot. We strongly recommend using 16 percent 50/50 grease. With this amount of lubricant (16%), you increase by 4 percent the amount of methanol in the fuel. It is methanol that cools your engine and it is methanol that gives you power. My Stalker 66 with 20 percent of the lubricant was always very hot due to the lack of cooling from methanol. When overheating all the time there was a deposit on the piston which acts like an abrasive on your cylinder and wears it quickly. This is exactly the case.
I wish you to quickly build a new aircraft for the Stalker 66.

Regards,Ruslan

Offline Randy Cuberly

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Re: Stalker Stunt Engines
« Reply #15 on: December 30, 2018, 08:34:34 PM »
Ruslan,

Thank you very much for the information on mounting the muffler.  Actually that is the exact information I was hoping for.

Steve H.  Thanks to you also for the info about the possibility of using a molded ring at the end of the muffler.  That is really what I was expecting to have to do but I'm very happy to hear that it is considered unnecessary on the 66.

Randy Cuberly
Randy Cuberly
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Offline Air Ministry .

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Re: Stalker Stunt Engines
« Reply #16 on: December 30, 2018, 08:36:38 PM »
This is underway for the Stalker 76 & Stalker 66 . Likely the 66 will do . How many 66 were built with the ' 61 ' case stamped ' 66 ' ??



The VERTIGO engine bay picture , V cunning . Tried to fiind a picture of an auto - Spring / Saddle Ex Mount .
Basically the sping loops over ' the pipe ' onto hooks . Holding it on ' the sddle ' till the diff knocks it down .
As it goes under the rear axle . To eliminate supurflous bends . Olde 250 GT ferroary like . Like Yours .

The thing was , it allowed longitudeinal expansion ( with heat ) , and allowed for a ' Q.D. Exhaust . For getting at other things quick .

Now we know .  :-\  :-\ Just a thought , for if you ARE going to support it .

---------------------------------------------------------------------------------------------------------------------------------------------------

Offline Steve Helmick

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Re: Stalker Stunt Engines
« Reply #17 on: December 30, 2018, 08:55:21 PM »
Ruslan,

Thank you very much for the information on mounting the muffler.  Actually that is the exact information I was hoping for.

Steve H.  Thanks to you also for the info about the possibility of using a molded ring at the end of the muffler.  That is really what I was expecting to have to do but I'm very happy to hear that it is considered unnecessary on the 66.

Randy Cuberly

Ruslan surprised me on that. I'm pretty sure that at least some of the (3) Stalker mufflers I have has a round thingy cast onto the rear of the muffler for that purpose. Or so I was told by Stalker users. 

Most the guys I've seen with the screw-on .51 muffler had problems with the threads seizing or galling, so they installed the muffler once, permanently, and then cut the "header" tube roughly in half and spliced it back on with a bit of silicon hose normally used for tuned pipes...in case anybody in the SH reader group has one. Locally, the .51 has more history and fans than the other Stalkers.   y1 Steve
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Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #18 on: December 31, 2018, 02:39:14 AM »
Ruslan-
I had thought that there was a .55 in the line up before?

Kind Regards,
Target
Hello Target
The company Stalker never produced engines with the designation .55
Regards,Ruslan

Why don't you make an .049.
Hello Motormen
I think it would be very good if the Stalker company produced 0.49 engines. It is a pity, but now there is only model 0.51 in production. It seems to me that this is not a big difference for you!
Regards,Ruslan
This is underway for the Stalker 76 & Stalker 66 . Likely the 66 will do . How many 66 were built with the ' 61 ' case stamped ' 66 ' ??
The VERTIGO engine bay picture , V cunning . Tried to fiind a picture of an auto - Spring / Saddle Ex Mount .
Basically the sping loops over ' the pipe ' onto hooks . Holding it on ' the sddle ' till the diff knocks it down .
As it goes under the rear axle . To eliminate supurflous bends . Olde 250 GT ferroary like . Like Yours .

The thing was , it allowed longitudeinal expansion ( with heat ) , and allowed for a ' Q.D. Exhaust . For getting at other things quick .

Now we know .  :-\  :-\ Just a thought , for if you ARE going to support it .

---------------------------------------------------------------------------------------------------------------------------------------------------
Hello Matt
Is your new aircraft in the photo a copy of a real airplane? Very interesting project. I already wrote earlier that the Stalker 66 engine is a modified version of the 61 LT-LS engine whose piston diameter was increased from 23 mm to 24 mm. External dimensions and weight of the engine have not changed. These two engines differ only in the inscriptions on the crankcase. Some questions that you ask me are not clear. I find it hard to translate your Australian English correctly. I am not a very experienced translator.
Regards,Ruslan
Ruslan surprised me on that. I'm pretty sure that at least some of the (3) Stalker mufflers I have has a round thingy cast onto the rear of the muffler for that purpose. Or so I was told by Stalker users. 
Most the guys I've seen with the screw-on .51 muffler had problems with the threads seizing or galling, so they installed the muffler once, permanently, and then cut the "header" tube roughly in half and spliced it back on with a bit of silicon hose normally used for tuned pipes...in case anybody in the SH reader group has one. Locally, the .51 has more history and fans than the other Stalkers.   y1 Steve

Hello Steve
Silencers to Stalker engines .40 / .46 / .51 have the same parts of the middle part and the backs with an exhaust pipe where there is a protrusion for attaching the muffler to the body of the aircraft. This is done to reduce production. That is why you and your friends thought that all these silencers should be attached to the fuselage of the aircraft through an additional support with a rubber stop.
But only the Stalker .40 engine must necessarily have such an additional mount because it has a free (not rigid) mount of the muffler to the engine crankcase. You are also absolutely right that you can use a silicone pipe to connect the engine crankcase .40 / .46 / .51 with a silencer as on engines that work with a resonant tube. To do this, it is necessary to slightly modify the engine and muffler parts. This is a personal matter for each pilot to change or improve the design of the exhaust system for his particular model of aircraft and for the convenience of access to the fuel tank. But you should know that additional attachment of the silencer to the aircraft fuselage is necessarily necessary only for the Stalker engine .40
Regards,Ruslan

Offline Don Jenkins

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Re: Stalker Stunt Engines
« Reply #19 on: December 31, 2018, 06:22:26 AM »
Hello Don
You build very beautiful airplanes. I liked the one in the photo. It is a pity that you crashed your plane. It is a pity that the engine was also destroyed. You had one of the first engines Stalker. With the engine 61 LT-EX began the history of the company Stalker 15 years ago. Now in the production company Stalker 11 different engines. The stalker 66 that you purchased to replace the 61st engine is a very good choice. Crankcase dimensions are exactly the same and weight too. Only the propeller will need a little more. Not 330-340 mm in diameter, but 350 mm., And the screw pitch is not 150 mm and 160 mm.
The flight time you wrote it is actually exactly like that. For Stalker 61 fuel tank per 100 ml is enough for 7 minutes of work. For Stalker 66 this volume is enough for 6 minutes 30 seconds.
You wrote that you use fuel with 20 percent lubricant. This is a lot. We strongly recommend using 16 percent 50/50 grease. With this amount of lubricant (16%), you increase by 4 percent the amount of methanol in the fuel. It is methanol that cools your engine and it is methanol that gives you power. My Stalker 66 with 20 percent of the lubricant was always very hot due to the lack of cooling from methanol. When overheating all the time there was a deposit on the piston which acts like an abrasive on your cylinder and wears it quickly. This is exactly the case.
I wish you to quickly build a new aircraft for the Stalker 66.

Regards,Ruslan

Thanks for the kind words and information regarding fuel, I will make that change for the next one!

Don

Offline Michael Palm

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Re: Stalker Stunt Engines
« Reply #20 on: December 31, 2018, 09:13:24 AM »
Hello Target
The company Stalker never produced engines with the designation .55
Regards,Ruslan

Hello mr Kurenkov. I have friend in Finland, Alf Lindholm that has a Stalker 55. And when i lookd around the internet i found this :http://www.stalker-modusa.com/index3.htm  Is that a different company?
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Re: Stalker Stunt Engines
« Reply #21 on: December 31, 2018, 09:35:44 AM »
Hello mr Kurenkov. I have friend in Finland, Alf Lindholm that has a Stalker 55. And when i lookd around the internet i found this :http://www.stalker-modusa.com/index3.htm  Is that a different company?
Hello Michael
I meant that Stalker did not produce an engine with the designation 55 under its own brand and in a separate case. This engine was produced under the Modusa (Made in USA) brand for the American company and in the 61 engine crankcase with a reduced piston size.
Also under the Modusa brand, Stalker produced the engine with the designation 35 in one crankcase with engines 40 and 46 with plain bearings. But it was a long time ago, more than 15 years ago. These engines (35 and 55) were produced in small experimental batches and did not have a demand for which they were discontinued. They did not go to the series. So serially, in large quantities, Stalker did not produce the engine with the designation 55 exclusively under his own brand.

Regards,Ruslan
« Last Edit: December 31, 2018, 10:08:06 AM by Ruslan Kurenkov »

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #22 on: December 31, 2018, 01:30:23 PM »
.049 not 0.49
Hello Motorman !
Why do you need such a small engine? This is a very very small engine. Very tiny! I think it would be a very nice gift for collectors. It is a pity, but such small engines in the near future Stalker will not produce. Very sorry! Happy New Year to you and all the best!

Regards,Ruslan

Offline Michael Palm

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Re: Stalker Stunt Engines
« Reply #23 on: December 31, 2018, 01:50:17 PM »
Hello Michael
I meant that Stalker did not produce an engine with the designation 55 under its own brand and in a separate case. This engine was produced under the Modusa (Made in USA) brand for the American company and in the 61 engine crankcase with a reduced piston size.
Also under the Modusa brand, Stalker produced the engine with the designation 35 in one crankcase with engines 40 and 46 with plain bearings. But it was a long time ago, more than 15 years ago. These engines (35 and 55) were produced in small experimental batches and did not have a demand for which they were discontinued. They did not go to the series. So serially, in large quantities, Stalker did not produce the engine with the designation 55 exclusively under his own brand.

Regards,Ruslan

Thank You for making that clear!
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Re: Stalker Stunt Engines
« Reply #24 on: January 01, 2019, 05:45:49 PM »
Quote
Is your new aircraft in the photo a copy of a real airplane?





This ones 57 in. ST 21/40 . / HP 40 R P R . built 2000 .
Conceived 1976 , bigger one is 66 in span .  FOLKERTS SK3 . By Jupiter .





My 66 is STAMPED 66 . Got Via Brian Eather Via Kaz Minato . Brian says is the first 66 made ? .

Thanks .  H^^


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Re: Stalker Stunt Engines
« Reply #25 on: January 02, 2019, 11:56:23 AM »

My 66 is STAMPED 66 . Got Via Brian Eather Via Kaz Minato . Brian says is the first 66 made ? .

Thanks .  H^^


Hi Mat!
Thank you for the original photos of the prototype of your aircraft. It seems to me that you definitely need to put the number 301 on the aircraft as on the original.

Now I understand your question.
Indeed, on the first Stalker 66, the inscription on the crankcase was stamped (photo 1). Such engines were on sale until recently. Now the inscription on the crankcase 66 is applied in another way (photo 2).
I'm happy for you and your Stalker 66. There are a lot of Stalker engines in Australia. Recently, I sent a new Stalker 66 to my friend in Australia.
I wish you many good flights on our Stalker engines on our brass-plated lines!
Regards,Ruslan

Offline Steve Helmick

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Re: Stalker Stunt Engines
« Reply #26 on: January 02, 2019, 05:04:14 PM »
Ruslan, don't consider yourself alone in having difficulty with interpreting Matt's Australian English. We all struggle with it! He does post some interesting pictures, and occasionally writes something that makes sense. We keep urging him to do better...  LL~ Steve
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In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Target

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Re: Stalker Stunt Engines
« Reply #27 on: January 02, 2019, 08:12:16 PM »
I do'n't speeke Ausseeeee!!!
Regards,
Chris
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Re: Stalker Stunt Engines
« Reply #28 on: January 03, 2019, 08:46:03 PM »
Geetings and salutations to my followers and admirers . .  ;D H^^



New Supporters Club .  S?P

RIGHT , we'd better get back ON TOPIC .



« Last Edit: January 03, 2019, 09:08:12 PM by Matt Spencer »

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #29 on: January 20, 2019, 10:59:21 AM »
Hello, friends !
I want to test one of the engines Stalker with a resonant tube. It is a pity, but I absolutely do not understand anything in the design and construction of resonant tubes. I would like to hear from you kam me to make a resonant tube. How do I correctly calculate the pipe length and diameter? How to calculate the installation location of the partition inside the pipe and the diameter of the hole in the partition? What should be the size of the adapter that is attached to the crankcase of the engine diameter and length? Can someone use a resonant tube on Stalker engines?
Thank you !
Ruslan

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Re: Stalker Stunt Engines
« Reply #30 on: January 20, 2019, 04:21:05 PM »
Dear Ruslan,
I really do not know, if the "pipe" can work properly on a baffled piston engine.
As I know, the pipe always used with loop-scavenged (Schneurle) engines, but I can be wrong...
Istvan 

Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #31 on: January 20, 2019, 04:58:29 PM »
I really do not know, if the "pipe" can work properly on a baffled piston engine.
As I know, the pipe always used with loop-scavenged (Schneurle) engines, but I can be wrong...

   It can, theoretically, the same principles apply. Wisniewski's speed models were baffle-piston, as far as I know, and plenty of people were using tuned pipes on various baffle-piston engines spradically through the years. I even tried it (on an ST46), but near as I can tell, for stunt, everyone made more-or-less the same mistake - tried to run the same RPM with the same pitch they had before, and used the pipe to jack up the torque at that RPM so they could run a larger diameter prop. Worthless, essentially.

    The reason you don't see it too often is that baffle-piston engines have been obsolete for about 40 years and aren't generally available, for a very long time now. They were superseded long ago for almost all applications and all the baffle-piston engines were discontinued. People started trying to run schnuerle engines just like they had baffle-piston engines , and while at times it showed indications of VASTLY higher performance, they were really difficult to control to get the right amount of power at the right time. Hunt came close to figuring it out in 1980 with 4" pitch props and a muffler (which still works as long as you get everything just right (like the 20FP)), but the real breakthrough was realizing that you needed to use the tuned pipe as a regulator instead of a power-booster. With everything from a schneurle 40 on up, you have vastly more power available than you can possibly use - as opposed to never having enough like we used to have. The trick then changes from trying to jack up the marginal power available from baffle-piston engines to taming the vastly overkill power available with schneurle engines.

   The first really good competitive system was described in the 1991 "Impact" article, still arguable one of the best, but as we got better at it and understood the principles better, we moved from 40's to 51s to 61s to 75s. If you are going to put a piped schneurle 75 in a 630 square inch airplane, you had darn well better understand how to make the pipe act as a regulator!   We had one residual problem that plagued us for years - run asymmetry, much like Lauri talks about - and that was pretty conclusively resolved in 2003.

    The key is to run the engine a bit faster (around 11,000 in the air), and use a 4" pitch prop. The prop, and no pipe, provides most of the extreme increase in effectiveness, the issue being that you will find it difficult to keep it running in the required RPM range with just a muffler. Note that an ST46 would probably spin Paul Walker's 40VF prop fast enough to get the same lap time - but it will be deader than dead in the maneuvers, completely unacceptable, not as good as 6" of pitch.

    The above will probably set off another around of histrionic screeching from the usual quarters, but I have no stake in anything either way, so I think I am pretty objective.

    Brett

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Re: Stalker Stunt Engines
« Reply #32 on: January 20, 2019, 08:18:40 PM »
A bit irrelevant , but someone brought up the Pioneer in F2A , so . . .  General Referance only .
 The BSA stuffs worth a look . ( Old DKW derivative )

http://www.modelenginenews.org/people/wiz/wiz_pipe_man.html SPEED . Wisnewski . - PIPES . .





Just a note , seeing were here . S Tigre 40 in the yellow plane, on a 11 x 4 & maybe NO Muffler ,
Holds a hard notta lotta switch powerband .
No muffler & 20 % Nitro & a NINE mm Intake , C Case Pressure - Er Needs 20 Oz Fuel but goes well .  :-X seeing ST 46 & 4 inch pitch
was mentioed . The 11 x 4 was the ' wind prop ' on that and the HP 40 - with its 130 - 110 sleeve timing .V Stalkerish ,
tho unbaffled ( H P ) and rotary is 60 closing . V good wind / load response .

Hopeing to get that from the stalker , with bigish ( maybe 320 ) intake , and fine off on the pitch .

Baffles & tooned pipes should be ok. olde BSA Batman ( Bantam ) tuning tripe avail & they even ran Mega's .
Some pretty wierd / grotesq pistons in early 2 strokes .

https://www.google.com.au/search?q=bsa+bantam+porting&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwi_h_fa9_3fAhVCfn0KHa3tBEcQsAR6BAgGEAE&biw=1221&bih=854#imgrc=BF-Uq6CL0u3jkM:

Only Problem with early RACE 2 strokes was carrying a barometer & altering jetting if a cloud went near the sun .  :-X

I ran a pipe on a K&B Torpedo 15 R V  mid 70s , asymetric speed thing .  & in a goodyear . Theyre a baffle / loop motor  .
Just clowning round . Took a bit to get it ' on the pipe ' , But thats a SPEED ENGINE . as is info above .

So only broadly releveant & likely contrary to stunt - pipe  requirements . Theres the big Fitzgerald pipe artical .
On here ( S H ) too . I think .
« Last Edit: January 20, 2019, 08:40:51 PM by Matt Spencer »

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Re: Stalker Stunt Engines
« Reply #33 on: January 21, 2019, 07:02:18 AM »
Dear Ruslan,
I really do not know, if the "pipe" can work properly on a baffled piston engine.
As I know, the pipe always used with loop-scavenged (Schneurle) engines, but I can be wrong...
Istvan 
Thanks Istvan!
I am for this and want to spend this summer testing engine Stalker 66 with a resonant tube. I want to understand whether a single-channel longitudinal purge engine can work well with a resonant tube. Long-stroke engines Stalker with single-channel blowing are limited to maximum revolutions of 9000 rpm. The torque is much higher at these revolutions than that of short-stroke engines operating at 11,000 rpm. I want to use a three-bladed propeller 330mm in diameter and 150mm pitch. I want to understand whether the engine will keep the revs in a certain range as on engines with three-channel blowing like RoJet 68.
Regards,Ruslan

Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #34 on: January 21, 2019, 10:26:38 AM »
Thanks Istvan!
I am for this and want to spend this summer testing engine Stalker 66 with a resonant tube. I want to understand whether a single-channel longitudinal purge engine can work well with a resonant tube. Long-stroke engines Stalker with single-channel blowing are limited to maximum revolutions of 9000 rpm. The torque is much higher at these revolutions than that of short-stroke engines operating at 11,000 rpm. I want to use a three-bladed propeller 330mm in diameter and 150mm pitch. I want to understand whether the engine will keep the revs in a certain range as on engines with three-channel blowing like RoJet 68.
Regards,Ruslan

   The torque is higher than, say, a PA61, at 9000 rpm?  Got numbers for that? No offense intended or suggestion of falsehood, but I sincerely doubt it. Everybody else with their low-rev systems thought the same, until we measured it. But the actual measurements should tell us the truth, and fortunately, we have some.

     I would also add that this is not far off the "optimum" tuned RPM (peak of the pipe tuning curve) of a competitive pipe 61 system. It's tuned to around 9000-9500 RPM, launches at around 9700, and runs about 10500-10800 in level flight, at which point the HP curve is falling rapidly.  That's why it is a regulator.

      You can certainly do what you are suggesting (tune the system for ~6" of pitch as associated low rpm), but it means you are not going to see the sort of performance advantage what we have found, which requires around 4" of pitch. You are also going to require an very long pipe length. We used to run 13-6's (330-155 mm) on ST46s at acceptable in-flight speeds, and that was a standard prop for a ST60, so that makes me even more skeptical about how much "torque" we are talking about - since an ST60 has something like 60% the torque of a PA61 at those revs. It certainly takes far less shaft HP to fly a particular airplane around at 5.2 second laps on a 13-6 than it does to fly the same airplane around on a 13-3.75 3-blade.

    The measurement should prove interesting, we might all learn something.

     Brett

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Re: Stalker Stunt Engines
« Reply #35 on: January 21, 2019, 04:18:36 PM »
   The torque is higher than, say, a PA61, at 9000 rpm?  Got numbers for that? No offense intended or suggestion of falsehood, but I sincerely doubt it. Everybody else with their low-rev systems thought the same, until we measured it. But the actual measurements should tell us the truth, and fortunately, we have some.

     I would also add that this is not far off the "optimum" tuned RPM (peak of the pipe tuning curve) of a competitive pipe 61 system. It's tuned to around 9000-9500 RPM, launches at around 9700, and runs about 10500-10800 in level flight, at which point the HP curve is falling rapidly.  That's why it is a regulator.

      You can certainly do what you are suggesting (tune the system for ~6" of pitch as associated low rpm), but it means you are not going to see the sort of performance advantage what we have found, which requires around 4" of pitch. You are also going to require an very long pipe length. We used to run 13-6's (330-155 mm) on ST46s at acceptable in-flight speeds, and that was a standard prop for a ST60, so that makes me even more skeptical about how much "torque" we are talking about - since an ST60 has something like 60% the torque of a PA61 at those revs. It certainly takes far less shaft HP to fly a particular airplane around at 5.2 second laps on a 13-6 than it does to fly the same airplane around on a 13-3.75 3-blade.

    The measurement should prove interesting, we might all learn something.

     Brett

Hello Brett
Thank you for two very interesting and informative answers to my questions. I am very pleased with the productive communication. It’s a pity, but I don’t know how much torque the engine has with the PA-61 three-channel blow, but I know that this is a very powerful engine. And I did not compare the PA-61 or Ro-Jet 68 with Stalker. It's like comparing two engines of equal volume, only one ordinary atmospheric car engine running on 91st gasoline and the second with turbocharged air running on nitromethane. All high-tech modern engines with three-channel blowing have a very large capacity. They are much more powerful than single-channel engines. At the same time they have much more fuel consumption.
 The torque of a long-stroke engine is always higher than that of a short-stroke engine with the same volume and the same blowing system. I have a lot of data on the operation of Stalker 61 EX where the piston stroke is 22 mm and Stalker 61 LS where the piston stroke is 24 mm. On the 61 EX Stalker, the two-blade propeller 330mm/13in and pitch 150mm/5.9in were the most effective. On the Stalker 61 LS propeller 340mm/13.4in and pitch 160mm/6.3in. The volume of the engines and the purge system were the same. The diameter of the propeller directly proportional to the torque. The higher the torque, the larger the diameter of the propeller and the lower the revolutions. Someone likes to fly at high speeds and a small step of the propeller, and someone likes to fly at low speeds and a large step of the propeller. The speed of flight in a circle about the same. If you use a very powerful engine with a three-channel blowing, then somehow you will have to fly either at very low revs with a large propeller or at very high revolutions with a small step of the propeller. Both in the first and in the second case you will use only 50-60% of the power of your engine, otherwise your model will fly very very quickly. We specifically on Stalker engines do not use three-channel blowing, because there is a lot of power. At Stalker 66, we use the power to a maximum of 70 percent and on the Stalker 76 - a maximum of 60 percent of the possible. And we don’t fly at all on Stalker 81, we don’t know what to do with it, it turned out to be very powerful, we don’t need such power. On Stalker 76, we greatly increase the combustion chamber with additional gaskets to reduce the compression ratio and artificially greatly reduce power. That is why we do not use nitromethane. With nitromethane, we cannot reduce excess power. With such settings of the combustion chamber, the engine works like a 4-stroke engine, constantly in mode 4. If the motor is set incorrectly then in mode 2 the plane shoots like a cannon and flies like a mad upright and it doesn’t matter how much the plane weighs.
 I always used a Stalker 76 propeller with a diameter of 360mm/14.2in (with a smaller pitch for the cold) on my Stalker 66 when it was very hot in the summer. I don’t know a single engine with a volume of 10.85 cm. A cube that, having a single-channel purge, can easily turn a propeller (360mm/14.2in diameter and 160mm/6.3in pitch) in hot summer and at the same time dragging up an airplane weighing 1950 grams/68.8oz using only 100ml/3.38oz of fuel with 1.5% nitromethane.
And yet I want to test the engine Stalker with a resonant tube and publish for everyone who is interested their results. I really really want to understand the whole point and the whole point of using a resonant tube as a device capable of controlling turns, retaining excess power and adding power when it is not enough.
I want experts to tell me in which direction to go. So far, the resonant pipes for me contain only secrets that I want to guess with pleasure and use with your help.
Regards,Ruslan

Offline Istvan Travnik

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Re: Stalker Stunt Engines
« Reply #36 on: January 21, 2019, 04:59:37 PM »
Dae Ruslan,
My bid to achieve higher torque as follows:
take 130° outlet and 100°, maximun 105° scavenge angle, 170°, maximum 180° inlet angle,  8,6mm dia venturi with 4 mm spraybar, or 5,6 mm dia venturi with nozzle.
compression rate between 9 and 10. No need for Cooling ribs on cylinderhead, and make a series of different, insertable chromnickel steel deflector* into combustion chamber...
...and keep your own silencer -however with a little bit less tight choking, as possible.
Istvan

*see related topic : https://stunthanger.com/smf/open-forum/glow-plug-measurements/msg542745/#msg542745


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Re: Stalker Stunt Engines
« Reply #37 on: January 21, 2019, 05:04:21 PM »

 The torque of a long-stroke engine is always higher than that of a short-stroke engine with the same volume and the same blowing system.

Why do you think that is true?
Torque comes from BMEP - brake mean effective pressure.
Longer stroke means smaller bore, so for same pressure force is less.
In the end torque will about be the same.
MAAC 8177

Offline Ed Barry

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Re: Stalker Stunt Engines
« Reply #38 on: January 21, 2019, 06:05:34 PM »
Do you stock the new Discovery Retro "68"
Ed Barry NJ

Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #39 on: January 21, 2019, 09:03:26 PM »
Why do you think that is true?
Torque comes from BMEP - brake mean effective pressure.
Longer stroke means smaller bore, so for same pressure force is less.
In the end torque will about be the same.

   Note that I just let that one go by....

    Brett

Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #40 on: January 21, 2019, 11:33:32 PM »
The diameter of the propeller directly proportional to the torque. The higher the torque, the larger the diameter of the propeller and the lower the revolutions. Someone likes to fly at high speeds and a small step of the propeller, and someone likes to fly at low speeds and a large step of the propeller. The speed of flight in a circle about the same. If you use a very powerful engine with a three-channel blowing, then somehow you will have to fly either at very low revs with a large propeller or at very high revolutions with a small step of the propeller. Both in the first and in the second case you will use only 50-60% of the power of your engine, otherwise your model will fly very very quickly. We specifically on Stalker engines do not use three-channel blowing, because there is a lot of power. At Stalker 66, we use the power to a maximum of 70 percent and on the Stalker 76 - a maximum of 60 percent of the possible. And we don’t fly at all on Stalker 81, we don’t know what to do with it, it turned out to be very powerful, we don’t need such power. On Stalker 76, we greatly increase the combustion chamber with additional gaskets to reduce the compression ratio and artificially greatly reduce power. That is why we do not use nitromethane. With nitromethane, we cannot reduce excess power. With such settings of the combustion chamber, the engine works like a 4-stroke engine, constantly in mode 4. If the motor is set incorrectly then in mode 2 the plane shoots like a cannon and flies like a mad upright and it doesn’t matter how much the plane weighs.

   To quote a famous man "I *love it* when a plan comes together!"

    You are describing *exactly* the problem everybody else was having trying to make more powerful engines (like the OS 40/45 FSR, etc) work in a stunt plane in the late 70's/early 80s - right down the line. Excess power, excess power boost, excessive speed. Everybody tried your solutions - lower compression/nitro, adjusting the exhaust timing, etc. Windy (who was the last competitive flier trying to do it this way) was the last holdout. He also had the notion that "I have a 76 (or even a 91, as I recall), so why do I need a pipe?". We still have people trying to do that, half the posts here talk about throwing in 14 head gaskets and grinding the intake port to reduce the blowdown. That just makes it even more prone to running away.

    The answer is as above - th emore powerful the engine, the more you need the pipe. The problem you have with excess power is solved by putting a power regulator on it, AND, figuring out a way to waste power in level flight, but having it still be effective and predictable in the maneuvers. The solution is:

reduced pitch and diameter along with whatever increase in RPM that is required to get the right speed - this has the effect of making the propellor less efficient, thus permitting more shaft power to generated without excess speed in level flight, but a dramatic increase in efficiency dependent *strictly* on the airspeed. And a reduced variation in the prop load, because there is so much power being absorbed by parasitic drag on the prop, the increased induced drag in the maneuvers has less over affect on the feedback load.

a pipe tuned for an RPM *lower* than the level flight operating point, to increase the slope of the power curve at the operating point. This is essentially entirely dependent on the RPM and nearly nothing else, so it can't make it run away and done correctly, the power falls off a cliff as the RPM increases. Effectively you have much more and much more adjustable control over the power curve. I think the tuned RPM of my PA61 system was around 9000-9200 RPM based on the curve - but it turns 10800 in level flight. The power curve is extremely steep around 10800, falling rapidly. When we unloaded it in the ground testing, we couldn't get it over about 11,500 even with tiny little props. It spun a 14-6 wood prop at something like 9500 RPM - without touching the needle from the normal launch settings - 140-150 in-ounces, MUCH more than a Saito 72. And that was a mere 61 with about 6 years of running on it. We now manage even better with an even bigger engine.

  Note also- we had to figure it out on smaller engines (40's) because if you get it wrong with a 40, it only goes a little off the rails, if you get it wrong with an 88, you are in deep trouble almost immediately. That's *exactly* what happened to Windy and his Jett 91- 1% too much power, way too fast, 1% too little power, way too slow, a little too much power boost, it was like a rocket, and not enough, and it was dead. A smaller engine has less capability to do that, and it was necessary to get it really right on a 40 so you knew what to do with a 60 (and now a 75).

   With these gigantic engines, you *cannot tolerate* the sort of prop effiiciency you get with high-pitch large diameter props, you will have (as you have noted) difficulty keeping the level flight speeds consistent in different conditions, and you will get either JATO-boosted corners or have it feel "flat" with very tiny (almost unmeasurable) changes in the air. What you are doing with the compression, no nitro, etc, is *detuning* the engine to reduce it's capability in order to make it easier. We all tried that, we think it's better otherwise. You are having the same sorts of problems with the giant engines that we had with Schnuerle 40s (since they have about the same sort of capabilities).

   This is an *entirely solved* problem, we have it to the point we can run arbitrary-size engines in any size airplane, we pump the compression as high as we feel like and run as much nitro as we can carry - because we learned to control it.

   The only thing "wrong" with it, from your perspective, is that the noise is much higher, no matter what you do, because all that horsepower you are wasting has to go somewhere, and it's going into churning up the air and making noise (although we have reduce the diameter to the point it's not as bad as it was, say, back in 1991 when we were running props like 13-3.25 at 12,000). It's not as bad as running open exhaust, but can be annoying to hear 40VFs monotonously whining away all afternoon for 4 days. That's a more-or-less irrelevant consideration here, but maybe not for you. If so, you still can't solve it your way (in my opinion) because you will give up too much performance. Fortunately, there is a thing called a brushless DC motor that also works better.

    Obviously, you can do as you wish, and you will learn something regardless, but if you just want to solve the problem, I can assure you it has already been solved as described, your problems are essentially the same as the ones we had, we tried all these approaches, and this hasn't been an issue for competitive US fliers for at least 15 years, and more like 30.

     Brett

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Re: Stalker Stunt Engines
« Reply #41 on: January 22, 2019, 04:21:28 PM »
   To quote a famous man "I *love it* when a plan comes together!"

    You are describing *exactly* the problem everybody else was having trying to make more powerful engines (like the OS 40/45 FSR, etc) work in a stunt plane in the late 70's/early 80s - right down the line. Excess power, excess power boost, excessive speed. Everybody tried your solutions - lower compression/nitro, adjusting the exhaust timing, etc. Windy (who was the last competitive flier trying to do it this way) was the last holdout. He also had the notion that "I have a 76 (or even a 91, as I recall), so why do I need a pipe?". We still have people trying to do that, half the posts here talk about throwing in 14 head gaskets and grinding the intake port to reduce the blowdown. That just makes it even more prone to running away.

    The answer is as above - th emore powerful the engine, the more you need the pipe. The problem you have with excess power is solved by putting a power regulator on it, AND, figuring out a way to waste power in level flight, but having it still be effective and predictable in the maneuvers. The solution is:

reduced pitch and diameter along with whatever increase in RPM that is required to get the right speed - this has the effect of making the propellor less efficient, thus permitting more shaft power to generated without excess speed in level flight, but a dramatic increase in efficiency dependent *strictly* on the airspeed. And a reduced variation in the prop load, because there is so much power being absorbed by parasitic drag on the prop, the increased induced drag in the maneuvers has less over affect on the feedback load.

a pipe tuned for an RPM *lower* than the level flight operating point, to increase the slope of the power curve at the operating point. This is essentially entirely dependent on the RPM and nearly nothing else, so it can't make it run away and done correctly, the power falls off a cliff as the RPM increases. Effectively you have much more and much more adjustable control over the power curve. I think the tuned RPM of my PA61 system was around 9000-9200 RPM based on the curve - but it turns 10800 in level flight. The power curve is extremely steep around 10800, falling rapidly. When we unloaded it in the ground testing, we couldn't get it over about 11,500 even with tiny little props. It spun a 14-6 wood prop at something like 9500 RPM - without touching the needle from the normal launch settings - 140-150 in-ounces, MUCH more than a Saito 72. And that was a mere 61 with about 6 years of running on it. We now manage even better with an even bigger engine.

  Note also- we had to figure it out on smaller engines (40's) because if you get it wrong with a 40, it only goes a little off the rails, if you get it wrong with an 88, you are in deep trouble almost immediately. That's *exactly* what happened to Windy and his Jett 91- 1% too much power, way too fast, 1% too little power, way too slow, a little too much power boost, it was like a rocket, and not enough, and it was dead. A smaller engine has less capability to do that, and it was necessary to get it really right on a 40 so you knew what to do with a 60 (and now a 75).

   With these gigantic engines, you *cannot tolerate* the sort of prop effiiciency you get with high-pitch large diameter props, you will have (as you have noted) difficulty keeping the level flight speeds consistent in different conditions, and you will get either JATO-boosted corners or have it feel "flat" with very tiny (almost unmeasurable) changes in the air. What you are doing with the compression, no nitro, etc, is *detuning* the engine to reduce it's capability in order to make it easier. We all tried that, we think it's better otherwise. You are having the same sorts of problems with the giant engines that we had with Schnuerle 40s (since they have about the same sort of capabilities).

   This is an *entirely solved* problem, we have it to the point we can run arbitrary-size engines in any size airplane, we pump the compression as high as we feel like and run as much nitro as we can carry - because we learned to control it.

   The only thing "wrong" with it, from your perspective, is that the noise is much higher, no matter what you do, because all that horsepower you are wasting has to go somewhere, and it's going into churning up the air and making noise (although we have reduce the diameter to the point it's not as bad as it was, say, back in 1991 when we were running props like 13-3.25 at 12,000). It's not as bad as running open exhaust, but can be annoying to hear 40VFs monotonously whining away all afternoon for 4 days. That's a more-or-less irrelevant consideration here, but maybe not for you. If so, you still can't solve it your way (in my opinion) because you will give up too much performance. Fortunately, there is a thing called a brushless DC motor that also works better.

    Obviously, you can do as you wish, and you will learn something regardless, but if you just want to solve the problem, I can assure you it has already been solved as described, your problems are essentially the same as the ones we had, we tried all these approaches, and this hasn't been an issue for competitive US fliers for at least 15 years, and more like 30.

     Brett
Hello Brett
Many thanks for such a detailed answer. You have very good English. I fully understand 100% of what you have written about so much and in such detail. I see that we understand each other and speak the same (technical) language. The fact is that our piloting culture was very different from yours. We walked in one and the same direction for a very long time. We all pursued only one goal - victory. You won more, we won less. But the desire and you and we have always been on the highest level. Many years of struggle have engendered two different schools and two different approaches to achieving the same goal. Alas, it is. Now, when it is possible to afford different variants of equipment, then we try your equipment, and you try our equipment. And there is nothing bad or offensive about it. For example, I am not ashamed to say that I do not understand anything in the resonant tubes, because it will take a couple of years and I will know and understand absolutely everything, but only if you or someone from other pilots share information with me and with others. I am ready to share my information and my experience. I really want to understand how to correctly calculate the resonant tube for a different engine size? Under Stalker 61? Under Stalker 66 and 76? Under Stalker 81? Where to begin? What information should I provide about the engine (timing?) To get the data for the production of the resonant tube? And in general, what I want most of all is to hear from you the opinion that this is even possible or not? Installing a pipe on a Stalker?
Thanks to everyone who talks to me in this thread.
I wish you all a lot of good flights!
Regards,Ruslan

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Re: Stalker Stunt Engines
« Reply #42 on: January 23, 2019, 09:52:36 AM »
Dae Ruslan,
My bid to achieve higher torque as follows:
take 130° outlet and 100°, maximun 105° scavenge angle, 170°, maximum 180° inlet angle,  8,6mm dia venturi with 4 mm spraybar, or 5,6 mm dia venturi with nozzle.
compression rate between 9 and 10. No need for Cooling ribs on cylinderhead, and make a series of different, insertable chromnickel steel deflector* into combustion chamber...
...and keep your own silencer -however with a little bit less tight choking, as possible.
Istvan

*see related topic : https://stunthanger.com/smf/open-forum/glow-plug-measurements/msg542745/#msg542745


Hello Istvan
Thanks for the advice.
I already wrote earlier that the torque is quite high. Increase torque and power is not necessary. I want to know whether the engine with a longitudinal single-channel blowing with a deflector on the piston can work with a resonant tube. My phases of gas distribution on Stalker 66 and 76 engines are: fuel intake - 115 degrees, and the exhaust phase - 135 degrees. This is almost the classic version of the Stünt single-channel motors of the 70s, where the phases were 120 and 140 degrees, respectively. As far as I know, on modern engines with a resonant tube, the exhaust phase begins earlier and is equal to 150-170 degrees. (correct me if I'm wrong). Venturi is 8 mm. We do not increase this size, otherwise the engine begins to greatly increase the speed of the aircraft when raising the nose of the aircraft up. I carefully read the related topic on the selection of spark plugs. Through long experiments and tests, we came to such results. For Stalker 66 and smaller, it is better to use a hot candle, for example OS MAX A3 (№6). For Stalker 76 - only cold candles, for example OS MAX No. 8.
Regards,Ruslan
Why do you think that is true?
Torque comes from BMEP - brake mean effective pressure.
Longer stroke means smaller bore, so for same pressure force is less.
In the end torque will about be the same.
Hello Pat
I think this is true and my beliefs are based on personal experience. You correctly wrote that by increasing the stroke of the piston its diameter decreases and the force of the explosion in the combustion chamber presses on a smaller area. But you did not consider that the duration of the explosion on the piston increased. In addition to the stroke of the piston, the stroke of the piston also increases - this is the distance from the top point in the explosion of fuel to the exhaust. Increases the lever (the distance from the axis of rotation of the crankshaft to the axis of rotation of the connecting rod). And the lever is what can turn our planet over if we give a point of support (as Archimedes wrote). And you correctly wrote that in the end we get almost the same thing, but not with torque but with engine power (with power). Power really almost does not change if the engine size does not change, the power remains the same but only at lower revs. This was proved by us on tests using two identical engines with different piston stroke sizes - 22 and 24 mm. Both engines on tests showed the same result of thrust in kilograms. But only Stalker 61 with a piston of 22 mm produced this thrust at higher revs with a propeller of smaller pitch and smaller diameter. Stalker 61 with a piston of 24 mm showed the same result of thrust, but only at lower revs and with a propeller of larger diameter and larger pitch.
If the maximum engine power (thrust in kg) has not changed and the turnover has decreased, then we get only one possible result using the formula for calculating power - an increase in engine torque. (power is directly proportional to revolutions per minute and torque). If one value decreases, the other increases.
This is only our experience and my knowledge. I think it is normal if my point of view does not coincide with yours.
Regards,Ruslan
Do you stock the new Discovery Retro "68"
Ed Barry NJ
Hello Ed
FORA presented such a new engine to our young athlete junior for training. This junior with his father and trainer looked at the work of this motor from the side and at the work of Stalker 66, which was also presented to him for training by Oleg Korotchaev (director Stalker).
As a result, the young athlete chose the Stalker 66 engine and installed his aircraft. Later on this engine, he was the repeated champion of Ukraine, the European Championship medalist and World Championship medalist already on the Stalker 76 and in 2018 won the F2B Junior World Cup.
Personally, I Discovery Retro 68 really like the look, it is perfectly made, looks great, works great at higher speeds on the propeller with a pitch of 150 mm. But I do not like the sound of the exhaust. The taste and color of all the markers are different.
Regards,Ruslan
   Note that I just let that one go by....

    Brett
Hello Brett
Thank you for help!
I am very glad that you do not scold me much. It's true. I sometimes like to be smart and at the same time I try very hard not to offend anyone with my conclusions. I know very well about your professionalism, I know that you are one of the most experienced F2B athletes in America. I recently wrote on this forum but for a very long time I have been reading here and on the forum cl.stunt
Regards,Ruslan

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Re: Stalker Stunt Engines
« Reply #43 on: January 23, 2019, 10:19:31 AM »
Hi Ruslan,

Any kind of scavenging can benefit from a tuned exhaust system, so you don't have to worry about that. Schnürle is just more efficient and inherently less stable, and it benefits more from the stabilizing/regulating effect of pipe.
I think the easiest way to start would be to get a correct size pipe and find somewhere the pipe lenght chart (by Randy Smith?) and set all up according to it.
The parameters in the chart are exhaust duration in degrees and target rpm. Using them you set up the theoretical pipe lenght to start with.
Be prepared for increased fuel consumption.

Cheers, Lauri
« Last Edit: January 23, 2019, 11:51:06 AM by Lauri Malila »

Offline frank williams

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Re: Stalker Stunt Engines
« Reply #44 on: January 23, 2019, 03:35:09 PM »
Just to add to Brett’s historical comments ….. I had some beautiful runs with a piped ST60 back in the early days of pipes.  The key word in the previous sentence is “SOME”.  Every now and then it gave a beautiful and powerful lower rpm flight.  But most of the time it was unpredictable.  The problem as I later decided, having gained more tuned pipe experience, was the less than perfect connection of the pipe header to the engine.  The limited engine case area of the side exhaust engine makes a good tight connection very difficult, and any loss of the pressure of the exhaust pulse at this early connection is very destructive to proper pipe operation.  I had one of the early Stalker 61’s that came into the country and eventually did play with pipes on it.  This early version had the slip-on O-ring connection at the engine to header.  I’m glad to see that later motors now have a flanged bolt-on fitting.  Make sure you have a leak proof seal at this joint and you will have no problems running the motor with a pipe.

Offline pmackenzie

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Re: Stalker Stunt Engines
« Reply #45 on: January 23, 2019, 06:22:19 PM »
To understand how pipes work, read the pipe section in "Two stroke tuner's handbook", you can find it in pdf form via Google.
Note that they are trying to increase power, but the principles are well explained.
https://www.google.ca/search?source=hp&ei=yRJJXJewO8-c5wLK27P4Bg&q=two+stroke+tuners+handbook&oq=two+stroke+tuners+&gs_l=psy-ab.1.0.35i39j0l2j0i22i30l4.1294.4647..7616...0.0..0.279.2716.2j15j2......0....1..gws-wiz.....0..0i131j0i131i67j0i67.relxv4dC29A

Randy Smiths Pipe chart is a good starting point. The math is all simple linear relationships, so you can interpolate/extrapolate as you see fit for different RPMs and exhaust duration.

http://www.clstunt.com/PipChart.htm

Pat MacKenzie
MAAC 8177

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Re: Stalker Stunt Engines
« Reply #46 on: January 23, 2019, 07:11:55 PM »
Quote
My phases of gas distribution on Stalker 66 and 76 engines are: fuel intake - 115 degrees, and the exhaust phase - 135 degrees. This is almost the classic version of the Stünt single-channel motors of the 70s, where the phases were 120 and 140 degrees, respectively. As far as I know, on modern engines with a resonant tube, the exhaust phase begins earlier and is equal to 150-170 degrees. (correct me if I'm wrong)

 ~^ ~^ ~^

The RACING High R.P.M. motors have the 160 exhaust timing .

( Incidently the Ducted Fan motors have wide ' seperation ' Sometimes . Low Trans - High Ex . Like K&B 7.5 D.F. .  :P )

The HELICOPTER Motors have timing for ' Good pick - up ' ( Throttle up & down well ) Tho the FSR 45 is same as R C FSR 45 .  :P

Not a pipe man ( Smoke Rollies  LL~) But Cylinder Port Timing appears relaTED TO RPM'S . AS MUCH AS ANYTHING .

 A LOW R.P.M. Pipe Motor . one would think , would still have Low Timing .

The ' Blow Down ' Figure , again-at least on Racing Motors , is critical & essential to pipe function .
The ' back pulse ' has nowhere to ' trap ' the charge if sleeve timings symetrical  ( Same Trans & Ex - like Std. G-15 136/138 sleeve )

So appears you need maybe more blowdown . At least rather than less .
I think Al Rabes ST 46 bored and stroked to 60 , ended up at 109 Ex 90 Trans . Tho unpiped - obviously .

A few ' extreme ' experiments , at the edges of the logical theories / parameters - if they work at all,
may well define characteriastics AT the alternative biases . To get some ground knowledge .

Anyway . 20 degree blowdown would make sense . for a start .


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Re: Stalker Stunt Engines
« Reply #47 on: January 23, 2019, 07:16:24 PM »
The VF - OS have 144 - 122 timing . Crank 36 - 56 - ( Just like a S Tigre X 45 Brett .  ;D )



Dont they say they runnem at 11.000 odd , plus .  :-\

You can still run the 130/110 timing fast ( The Irvine 40 on 4 in pitch. )
The Merco 49 runs 130/110 also . baffled piston . 12x6 prop & 15 or 20 % nitro itll 4 stroke through a bit of wind
towing 2 kilo & & 1850 span , tho 8:1 aspect ratio . Unpiped .

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Re: Stalker Stunt Engines
« Reply #48 on: January 24, 2019, 01:05:35 AM »
Without going into a complete analysis, I will just say, Ruslan, that I really like what you guys are doing. I once described the Yatsenko similar approach as "an ST60 developed by qualified aerospace engineers".

  Please understand that I am not in any way attempting to discourage you from pursuing this line or reasoning, I am actually fascinated by it. Anything I say on the topic is intended to assist if possible.

    I think I would summarize my point as - we crossed the threshold from not having enough power and working to optimize the output, to having far more power than we could possibly use, almost 40 years ago. But the airplane takes the same .4-.5 HP it always has. The problem has shifted from trying to get more to trying to control what we have in a functional way. Both additional regulating features on the engines, and determining an optimum way of using the prop to dump the power in level flight and still have it become useful in the maneuvers. I posit that prop efficiency is your enemy, if you have way more power than you can use, hooking it up to the air more efficiently is the last thing you want to do. It also seems to mean that you don't need any power boosters on the engine itself, you need a regulator (and a very fast-acting regulator) that you can easily adjust.

   However you accomplish it, I think the two key ideas - you need to control the power from the engine much better than we used to, and we need to try to figure out a way to dump the excess power in level flight - are what we have discovered with the very extensive development we have undergone.

  I would also add that I was not actually responsible for any of these ideas - they evolved mostly by trial-and-error by other people with the drive and the willingness to try new things, whether they had a full picture of why it worked or what exactly they were doing in an engineering sense. My sole contribution, if any, was trying to figure out why it works, and telling people about it.

     Brett

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Re: Stalker Stunt Engines
« Reply #49 on: January 24, 2019, 09:55:58 AM »
The VF - OS have 144 - 122 timing . Crank 36 - 56 - ( Just like a S Tigre X 45 Brett .  ;D )


   OK, but I am not sure what your point would be, I am quite well aware of the numbers for a OS 40VF. And my #1 RO-Jett has the same 144 degree exhaust timing - that was the "mistake" they made, they started with 140 degrees, wanted to move it to 136 just like the PA, and Dub turned the crank the "wrong" way (or more likely, added .004 instead of subtracting .004 in his CAD milling machine) and wound up with 144 instead.

 I have tried all three versions, the longer the exhaust timing, the smoother the break, same with the OS VFs, the best individual 40VF has 145 from tolerance stackup, the least is about 141-142. (although all are OK). I have run 136, 140, and 144 degree versions of the RO-Jett, and I think the 140 and 144 are about as good, and the 136 less desirable, although still good and perfectly usable.

   Same with the crankshaft timing. They started with a special narrow-timed stunt version of the crankshaft, didn't want to have special parts for the low-volume stunt engine, and tried one from a QM40 RC racing engine - and it ran better and smoother.
   
 The bar-stock version runs different than the cast case, and there is one additional feature that makes it run different that I decline to mention.

   All this goes to the discussion above - physics is real and magic and mysticism is not real. That's surprisingly hard for stunt people to grasp, or, they hang on to something that seems like "engineering" like the exhaust duration, then treat that like it's magic and ignore everything else. And, most of them have *no idea whatsoever* what they really need to successfully fly stunt in the year 20189, and steadfastly refuse to listen to anything else, to a fault in many cases.

 The same principle also suggests that the ST x45 has similar characteristics, but that is rather a moot point when anyone can probably get an infinite supply of PA40/51/61/65s, OS40/46VFs, that are probably rusting on a shelf in someone's garage, or RO-Jetts made to order in two weeks in any configuration (but get the "Brett" version) . Or a K77, PA75, or a Plettenburg and Axi. There is also no guarantee that the different thermal characteristics (that also matter) are the same, so with a ST X45, you are setting yourself on a two-year quest to figure out exactly what you need, when you can take any of the others and stick it in an airplane and have nationals-class runs this weekend. And the X45 appears to have have been discontinued for years, too, and are much harder to find, parts are close to non-existent, etc.

     Brett

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Re: Stalker Stunt Engines
« Reply #50 on: January 24, 2019, 02:23:56 PM »
   OK, but I am not sure what your point would be, I am quite well aware of the numbers for a OS 40VF. And my #1 RO-Jett has the same 144 degree exhaust timing - that was the "mistake" they made, they started with 140 degrees, wanted to move it to 136 just like the PA, and Dub turned the crank the "wrong" way (or more likely, added .004 instead of subtracting .004 in his CAD milling machine) and wound up with 144 instead.

 I have tried all three versions, the longer the exhaust timing, the smoother the break, same with the OS VFs, the best individual 40VF has 145 from tolerance stackup, the least is about 141-142. (although all are OK). I have run 136, 140, and 144 degree versions of the RO-Jett, and I think the 140 and 144 are about as good, and the 136 less desirable, although still good and perfectly usable.

   Same with the crankshaft timing. They started with a special narrow-timed stunt version of the crankshaft, didn't want to have special parts for the low-volume stunt engine, and tried one from a QM40 RC racing engine - and it ran better and smoother.
   
 The bar-stock version runs different than the cast case, and there is one additional feature that makes it run different that I decline to mention.

   All this goes to the discussion above - physics is real and magic and mysticism is not real. That's surprisingly hard for stunt people to grasp, or, they hang on to something that seems like "engineering" like the exhaust duration, then treat that like it's magic and ignore everything else. And, most of them have *no idea whatsoever* what they really need to successfully fly stunt in the year 20189, and steadfastly refuse to listen to anything else, to a fault in many cases.

 The same principle also suggests that the ST x45 has similar characteristics, but that is rather a moot point when anyone can probably get an infinite supply of PA40/51/61/65s, OS40/46VFs, that are probably rusting on a shelf in someone's garage, or RO-Jetts made to order in two weeks in any configuration (but get the "Brett" version) . Or a K77, PA75, or a Plettenburg and Axi. There is also no guarantee that the different thermal characteristics (that also matter) are the same, so with a ST X45, you are setting yourself on a two-year quest to figure out exactly what you need, when you can take any of the others and stick it in an airplane and have nationals-class runs this weekend. And the X45 appears to have have been discontinued for years, too, and are much harder to find, parts are close to non-existent, etc.

     Brett

And this is why I snap up VF's whenever I see them. The big problem I forsee in the future is finding light pipes and long enough headers.
Greg Kowalski
AUS 36694

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #51 on: January 24, 2019, 03:01:57 PM »
Hi Ruslan,

Any kind of scavenging can benefit from a tuned exhaust system, so you don't have to worry about that. Schnürle is just more efficient and inherently less stable, and it benefits more from the stabilizing/regulating effect of pipe.
I think the easiest way to start would be to get a correct size pipe and find somewhere the pipe lenght chart (by Randy Smith?) and set all up according to it.
The parameters in the chart are exhaust duration in degrees and target rpm. Using them you set up the theoretical pipe lenght to start with.
Be prepared for increased fuel consumption.

Cheers, Lauri
Hi Lauri
Thank you for participating in the discussion of my future project about installing our Ukrainian engine Stalker 76 RE (with rear exhaust) - American tuned exhaust system, which will regulate the maximum and minimum engine speed. I'll take your advice on changing the volume of the fuel tank.
  How do I solder a new tank? What should be its volume?
Regards,Ruslan
Just to add to Brett’s historical comments ….. I had some beautiful runs with a piped ST60 back in the early days of pipes.  The key word in the previous sentence is “SOME”.  Every now and then it gave a beautiful and powerful lower rpm flight.  But most of the time it was unpredictable.  The problem as I later decided, having gained more tuned pipe experience, was the less than perfect connection of the pipe header to the engine.  The limited engine case area of the side exhaust engine makes a good tight connection very difficult, and any loss of the pressure of the exhaust pulse at this early connection is very destructive to proper pipe operation.  I had one of the early Stalker 61’s that came into the country and eventually did play with pipes on it.  This early version had the slip-on O-ring connection at the engine to header.  I’m glad to see that later motors now have a flanged bolt-on fitting.  Make sure you have a leak proof seal at this joint and you will have no problems running the motor with a pipe.
Hello Frank
Thanks for the interesting information. Please write your results using the resonant tube on Stalker 61. How did the system work?
We really changed now the mounting of the muffler to the engine crankcase. Rubber pads quickly collapsed. Now we fasten the silencer with stainless steel bolts (this is important, black, red-hot bolts are destroyed) and have ceased to use gaskets that were constantly torn when opened during dismantling. Now we use only automotive sealant for engine repair, which we apply with a thin layer of 0.015 inches and immediately clamp the bolts. Before installing the muffler, put a little thread lock on the bolts. This connection works without problems the whole season - 300-400 flights.
Regards,Ruslan
To understand how pipes work, read the pipe section in "Two stroke tuner's handbook", you can find it in pdf form via Google.
Note that they are trying to increase power, but the principles are well explained.
https://www.google.ca/search?source=hp&ei=yRJJXJewO8-c5wLK27P4Bg&q=two+stroke+tuners+handbook&oq=two+stroke+tuners+&gs_l=psy-ab.1.0.35i39j0l2j0i22i30l4.1294.4647..7616...0.0..0.279.2716.2j15j2......0....1..gws-wiz.....0..0i131j0i131i67j0i67.relxv4dC29A

Randy Smiths Pipe chart is a good starting point. The math is all simple linear relationships, so you can interpolate/extrapolate as you see fit for different RPMs and exhaust duration.

http://www.clstunt.com/PipChart.htm

Pat MacKenzie
Hello Pat
I am very carefully studying the information about the systems configured exhaust two-stroke engines that you gave me. thank
Also, thank you for the table for calculating the parameters of the resonant tube from Randy Smith.
Thank you very much Randy for your work !!!
I will use these parameters to calculate the size of the resonant tube for my Stalker 76 PE with an exhaust of 135 degrees.
Regards,Ruslan
~^ ~^ ~^

The RACING High R.P.M. motors have the 160 exhaust timing .

( Incidently the Ducted Fan motors have wide ' seperation ' Sometimes . Low Trans - High Ex . Like K&B 7.5 D.F. .  :P )

The HELICOPTER Motors have timing for ' Good pick - up ' ( Throttle up & down well ) Tho the FSR 45 is same as R C FSR 45 .  :P

Not a pipe man ( Smoke Rollies  LL~) But Cylinder Port Timing appears relaTED TO RPM'S . AS MUCH AS ANYTHING .

 A LOW R.P.M. Pipe Motor . one would think , would still have Low Timing .

The ' Blow Down ' Figure , again-at least on Racing Motors , is critical & essential to pipe function .
The ' back pulse ' has nowhere to ' trap ' the charge if sleeve timings symetrical  ( Same Trans & Ex - like Std. G-15 136/138 sleeve )

So appears you need maybe more blowdown . At least rather than less .
I think Al Rabes ST 46 bored and stroked to 60 , ended up at 109 Ex 90 Trans . Tho unpiped - obviously .

A few ' extreme ' experiments , at the edges of the logical theories / parameters - if they work at all,
may well define characteriastics AT the alternative biases . To get some ground knowledge .

Anyway . 20 degree blowdown would make sense . for a start .


Hi Matt
How are you?
I see from your knowledge that on the other end of the World, too, use customized exhaust systems?
Thank you.
Regards,Ruslan

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Re: Stalker Stunt Engines
« Reply #52 on: January 24, 2019, 05:09:13 PM »
Quote
I see from your knowledge that on the other end of the World, too, use customized exhaust systems?

YES .





Comes ' on the pipe ' at 7-200 - 7-300 .  ;D  Runs thru to 8100 . Settled in top will run out to valve float at 8500 .

 LL~ LL~ LL~ Thats ' John the Hippie ' ! a Forester .  :-\ On the way to see Bob Dylan. We wont mention the Chain Guard .
Intresting you could anchor up H A R D at 60 , with the left peg near dragging . Blind corner and a logging truck at 10 mph
ahead on the hill .
His first pillion trip . " Just look over my shoulder INSIDE the turn . Lived way out on the gravel by the lakes . Helmets actually BLUE.

Where were we . 27 1/2 Valve Face to end . 1 3/4 o.d. Pluss Wassel Megas . Full length perforated tube baffle . Goes Incandescent .
Cut up the top too , a few inches . To tuck them up & in  .

the Norton Below ran the same pipes ( Mufflers !  ::) LL~ ) smaller dia. headers. 72 PR 5 speed . Had the legs on his Brothers
SS 750 Blue Frame dew cati , top end and acceleration .. Wonders what 600 bucks would do for you back then . Mid 70s .
Two P U Bonnies for $ 300 . A T120 Manx for 600. Make ya weep . All the butchered stuff on ebay .  :o >:(

Yellow Peril was alledgedly timed at 160 on methanol .



Er , that was wot you meant. wasn it .

No worries Brett .  Super tigres on the Brain . wont be piped . Be in the air now bar its 21-46 bolt pattern mount , Not the OS pattern .
After the cycles ones thinking COMBAT theyre using Ferraris for Demo derbies . As it were , with their 21/35s .  :(
Actually . Now Ferraris ARE mass production , you could use them for demo derbis . Like the Japs .  ;D



 H^^

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Re: Stalker Stunt Engines
« Reply #53 on: January 25, 2019, 04:37:12 AM »
Without going into a complete analysis, I will just say, Ruslan, that I really like what you guys are doing. I once described the Yatsenko similar approach as "an ST60 developed by qualified aerospace engineers".

  Please understand that I am not in any way attempting to discourage you from pursuing this line or reasoning, I am actually fascinated by it. Anything I say on the topic is intended to assist if possible.

    I think I would summarize my point as - we crossed the threshold from not having enough power and working to optimize the output, to having far more power than we could possibly use, almost 40 years ago. But the airplane takes the same .4-.5 HP it always has. The problem has shifted from trying to get more to trying to control what we have in a functional way. Both additional regulating features on the engines, and determining an optimum way of using the prop to dump the power in level flight and still have it become useful in the maneuvers. I posit that prop efficiency is your enemy, if you have way more power than you can use, hooking it up to the air more efficiently is the last thing you want to do. It also seems to mean that you don't need any power boosters on the engine itself, you need a regulator (and a very fast-acting regulator) that you can easily adjust.

   However you accomplish it, I think the two key ideas - you need to control the power from the engine much better than we used to, and we need to try to figure out a way to dump the excess power in level flight - are what we have discovered with the very extensive development we have undergone.

  I would also add that I was not actually responsible for any of these ideas - they evolved mostly by trial-and-error by other people with the drive and the willingness to try new things, whether they had a full picture of why it worked or what exactly they were doing in an engineering sense. My sole contribution, if any, was trying to figure out why it works, and telling people about it.

     Brett

Hello Brett
It was very nice to read your message. You have written everything very intelligibly and clearly, and the most important thing is that with love for the sport and from a pure heart. If aeronautical modeling were taught at the Massachusetts Institute of Technology, then I’m 100% sure that you would be the best teacher. Thank !
I have a few questions for you:
1. How do you solve the problem of the rear center of gravity of your aircraft when you perform the latest pieces of the aerobatic complex?
2. How effective is an engine with a tuned exhaust and a propeller of smaller diameter (smaller than ours) performs the role of an aerodynamic brake to reduce the vertical speed when flying to the bottom in the first figure of the "double coup" complex and in the hourglass figure between the third and fourth by turning?
3. Why do you use fuel with nitromethane for very powerful PA-75 engines?
4. According to Randy Smith’s resonance tube design table for my Stalker 76 with an exhaust phase of 135 degrees, should I use a 18-inch pipe and three-fourths of an inch for 9000 turns? It is right? Is the length of the pipe the distance from the center of the piston to the pre-wall?
Regards,Ruslan

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Re: Stalker Stunt Engines
« Reply #54 on: January 25, 2019, 01:09:00 PM »
Just to add to Brett’s historical comments ….. I had some beautiful runs with a piped ST60 back in the early days of pipes.  The key word in the previous sentence is “SOME”.  Every now and then it gave a beautiful and powerful lower rpm flight.  But most of the time it was unpredictable.  The problem as I later decided, having gained more tuned pipe experience, was the less than perfect connection of the pipe header to the engine.  The limited engine case area of the side exhaust engine makes a good tight connection very difficult, and any loss of the pressure of the exhaust pulse at this early connection is very destructive to proper pipe operation.  I had one of the early Stalker 61’s that came into the country and eventually did play with pipes on it.  This early version had the slip-on O-ring connection at the engine to header.  I’m glad to see that later motors now have a flanged bolt-on fitting.  Make sure you have a leak proof seal at this joint and you will have no problems running the motor with a pipe.

I would add to your comment Frank, that my gut feeling is using one of Brian's aftermarket ABC P/L sets in your ST60 (along with a better header seal) would also help yield very consistent good piped runs, with ST60 rings being what they were.
EricV

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Re: Stalker Stunt Engines
« Reply #55 on: February 01, 2019, 02:50:11 PM »
Hello, friends !
Today we will publish for you all the basic dimensions of our engines with the location of the exhaust back. We know how important the installation dimensions are when building and designing your new aircraft. This list of sizes will allow you to make the right choice of engine for your aircraft. A little later, we will publish the size of our engines with exhaust in the side.
We wish you many good flights on our lines and our engines.
https://drive.google.com/open?id=1yrdq6R8i03Jdesvh9ZYcst3K-cWFMoKc
Regards
team controllineparts

Offline Ruslan Kurenkov

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Re: Stalker Stunt Engines
« Reply #56 on: February 11, 2019, 02:14:03 PM »
Hello, friends !
Today I measured all sizes on Stalker engines with exhaust to the side, and transferred to paper. These are just 3 engines. I think my work will help someone.

https://drive.google.com/drive/folders/1C36AUy_IpyScfk279qEJ8Oz9_rlQsn9O?usp=sharing

Wishing you a good flight!

Offline John Lindberg

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Re: Stalker Stunt Engines
« Reply #57 on: February 17, 2019, 02:38:01 PM »
My OS 40VF ($135.00 off Ebay, NIB) has been running now for probably 5 years, runs like a top, uses, as Brett said, about 4.5 ounces of 10% fuel. I had it in a overweight Impact (73 ounces, ouch!) that little engine hauled it around real good, no problem!    #^ #^ #^

Offline Brian Gardner

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Re: Stalker Stunt Engines
« Reply #58 on: February 17, 2019, 03:05:57 PM »
Just a reminder to my fellow Aussies that I'm still the Stalker dealer here.

Brian

Offline pmackenzie

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Re: Stalker Stunt Engines
« Reply #59 on: February 17, 2019, 03:35:37 PM »
My OS 40VF ($135.00 off Ebay, NIB) has been running now for probably 5 years, runs like a top, uses, as Brett said, about 4.5 ounces of 10% fuel. I had it in a overweight Impact (73 ounces, ouch!) that little engine hauled it around real good, no problem!    #^ #^ #^

And your point is?

Good example of thread crapping  S?P
MAAC 8177

Offline Target

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Re: Stalker Stunt Engines
« Reply #60 on: February 17, 2019, 04:41:53 PM »
My OS 40VF ($135.00 off Ebay, NIB) has been running now for probably 5 years, runs like a top, uses, as Brett said, about 4.5 ounces of 10% fuel. I had it in a overweight Impact (73 ounces, ouch!) that little engine hauled it around real good, no problem!    #^ #^ #^
The pipe that (I assume) you are using cost you something though, right? Are you on the first or second pipe? The cost of the pipe brings the cost very close to the cost of a more expensive engine, to be fair, I would think.
Lots of ways to skin the cat it seems. Which makes things nice for us.

R,
Target
Regards,
Chris
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Offline Brett Buck

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Re: Stalker Stunt Engines
« Reply #61 on: February 17, 2019, 06:12:14 PM »
The pipe that (I assume) you are using cost you something though, right? Are you on the first or second pipe? The cost of the pipe brings the cost very close to the cost of a more expensive engine, to be fair, I would think.

     For fear of incensing Pat further, you need a pipe for the more expensive engine, too, so a $450 engine $125 is still more expensive than $125 engine with a $125 pipe. The fact that the $125 engine also runs better than many of the $450 engines helps, too.

    All of this cost is in the noise for the competitors, *travel cost* is by far the most expensive element. Your engine is going to last 10 years, $450 might be one weekend worth of gas/hotel bills.

    Brett

Offline John Lindberg

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Re: Stalker Stunt Engines
« Reply #62 on: February 18, 2019, 07:56:16 AM »
As far as the pipe goes, I already had a brand new 60-size Randy Smith pipe I bought along with a PA 51 in 2005. I had the PA 51 in a scratch built Staris, ran it with a header muffler set-up, which was popular in my club at the time. The remains of the Staris can be seen in the 2017-3, page 1 of Stunt News. It's in the upper right hand corner. Also, you can see it on page 65. Scott Richlen, a member of our club, thinks it's funny to print it. Brett is right, even the rooms at the "Blue Mountain hotel" have gone up, the stoop leading to the front door of each room (all ten of them) was a cinder block. It's on John Brodak's list of "Accommodations in Uniontown"- the birthplace of George C. Marshall. There is a tall office building downtown with a large mural of Marshall painted on it. "Fracking" has caused vacancy's in the area to disappear! Still running the same pipe, runs great! Got it in a Randy Smith "Satona"-nice plane! ~>

Offline Target

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Re: Stalker Stunt Engines
« Reply #63 on: February 18, 2019, 12:14:03 PM »
None of the Stalker engines listed are $450.
40-46 are 250 or less.
51-66 are 300 or less.
76-18 are 360 and 380.

Thank John for reporting on the longevety of the tuned pipe, that is good to know for sure
Regards,
Chris
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Offline John Lindberg

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Re: Stalker Stunt Engines
« Reply #64 on: February 18, 2019, 12:34:31 PM »
I'm hardly an "expurt" on pipes, used some when I flew R/C, the metal ones, they were noisy! The Randy pipe works, the VF 40 has quite a lot of power with it. Set it up like Brett posted on Stuka Stunt a number of years ago. It's all paid for!  #^

Offline Scott Richlen

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Re: Stalker Stunt Engines
« Reply #65 on: February 19, 2019, 09:29:44 AM »
Quote
The remains of the Staris can be seen in the 2017-3, page 1 of Stunt News. It's in the upper right hand corner. Also, you can see it on page 65. Scott Richlen, a member of our club, thinks it's funny to print it.

Nope, not funny.  Why do people watch NASCAR?  The tension is the big car wreck.  What's the tension of PA or any stunt event?  The big crash!  It's a key ingredient of the excitement of watching really good PA.  When someone has a low pull-out you can hear everyone go "Oooooh!"

Why is RC so boring?  Because it is way up in the sky, no danger there!  Why is YouTube RC fun to watch?  Why, it's always of crash compilations!

John: send me some more pictures of your crashes.  How about your Impacts' impact?  I'll stick them in Stunt News.  You'll be famous!!

Offline John Lindberg

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Re: Stalker Stunt Engines
« Reply #66 on: February 19, 2019, 12:16:58 PM »
The Impact is still in one piece! No one to watch my flights at the flying circle! mw~ mw~

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Re: Stalker Stunt Engines
« Reply #67 on: February 19, 2019, 01:09:35 PM »
Oh-oh.  So, your Impact never impacted?

It must have been your Thunder-Gazer that decided to do some Thunder-Grazing..... ;D

Send those pictures and I'll get them into Stunt News.....maybe we can do a special issue: "Ka-pow!  The many former models of John Lindberg and their short, dramatic life."  You'll be more famous than Brett!  S?P

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Re: Stalker Stunt Engines
« Reply #68 on: February 19, 2019, 03:53:50 PM »
No more pictures! The Thunder gazer was 2 years old, the Staris was over 10, the Impact is appx. 5 years old!  ~^

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Re: Stalker Stunt Engines
« Reply #69 on: February 25, 2019, 06:35:32 AM »
Hello, friends !
Congratulations on your upcoming New Year!
I want to wish you all a good mood and a lot of good flights in 2019.
Controllineparts will do its best to ensure that your flights on our lines and engines are successful and bring you only positive emotions.
I want to invite you to discuss all questions about the use of different Stalker stunt engines in this particular special topic.
I want to invite you to ask here any questions on the selection of the stunt engine for your aircraft, on the technical parameters and installation sizes of various Stalker engines, on installing the correct propeller size on your engine and on the fuel composition, on using the correct type of glow plugs and providing spare parts.
I will be happy to answer all your questions and will gladly take part in the discussion of all issues related to the repair and maintenance of the stunt engine Stalker.
Today we have in stock more than 10 Stalker, varying in size and location of the engine muffler, from the smallest 0.40 to the most powerful 0.81. I think that such a wide range of stunt engines will be able to satisfy both the novice and professional pilot. We also provide full technical support to our customers and the provision of any spare parts for our engines.

Regards
Ruslan Kurenkov

Ruslan,

I mounted my Stalker .61 inverted and had no issues.  I recently heard the .66 has trouble running inverted and the fix is to mount it horizontal or at 220 degrees.  Any thoughts or comments?

Don
« Last Edit: February 26, 2019, 06:46:14 AM by Don Jenkins »

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Re: Stalker Stunt Engines
« Reply #70 on: February 25, 2019, 08:08:55 AM »
Hello, Don.
Engine Stalker 61 and Stalker 66 are exactly the same in operation and adjustment engines with the same installation and dimensions.
On my plane, 5 years ago, the Stalker 66 engine was installed horizontally (270 degrees) when looking at the plane from the front. The engine worked perfectly, for 2 years I made 800 flights. Parallel with me on the same airfield our junior Kucher Nikolay (3rd place in the World Championship 2018) trained on the Stalker 66 which I installed him with the cylinder down (it is 180 degrees when viewed from the front). For three years he made 1500 flights on this plane and on this engine and became a three-time champion of Ukraine among juniors in the class F2B. I personally attended half of these flights. The engine worked fine, but only under certain conditions.
1. Turns on the earth - 7800 ob.min. (for this you need to use a propeller of 350mm by 160mm), the speed of a circle is 5.3 seconds on lines of 65 feet.
2. The glow plug is only hot (we use OS MAX A3, No. 6, Hot) - if the engine rpm is 7500 rpm in cold weather and you install a cold glow plug, for example OS MAX No. 8, then at the location of the cylinder down vertically there may be problems with the engine choking at sharp corners.
3. The amount of engine oil in the fuel - no more than 16 percent. (8 percent - castor and 8 percent - synthetic). At low revs - 7500, in the cold, and with a lubricant content of more than 20 percent, the engine can also sometimes be choked by a large amount of oil falling on a cold glow plug. I had it once when I installed a cold glow plug (Cold) and added castor oil up to 20 percent (without synthetics). My motor, which was mounted 270 degrees to the side of the cylinder -
 has stopped. As you can see when mistreating the engine, it does not matter how it is installed.
The best location of the engine is 225 degrees at the sight of the previous one. It is not in the side and not down - it is in the middle between them. With this arrangement, the engine works perfectly everywhere and best of all - at the top, above 45 degrees, on the figure "eight overhead". With this arrangement, the engine is very convenient silencer goes under the fuel tank.
Regards
Ruslan Kurenkov

Offline Guy Markham

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Re: Stalker Stunt Engines
« Reply #71 on: February 25, 2019, 08:38:55 PM »
Please show picture of engine   "225 degrees" with engine silencer under fuel tank . Thanks.
You only have to floss the teeth you want to keep!

Offline Scott Richlen

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Re: Stalker Stunt Engines
« Reply #72 on: February 26, 2019, 08:47:43 AM »
That's a good-looking wood 3-blade.  Who makes those?

Offline Perry Rose

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Re: Stalker Stunt Engines
« Reply #73 on: February 26, 2019, 10:06:19 AM »
What about mounting the engine at 90 degrees or 135 degrees??
I may be wrong but I doubt it.
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Re: Stalker Stunt Engines
« Reply #74 on: February 26, 2019, 10:54:48 AM »
Please show picture of engine   "225 degrees" with engine silencer under fuel tank . Thanks.
Hello Guy
Here is a photo of my aircraft with a Stalker 76 engine with a cylinder angle of 225.
On the previous plane, my Stalker 66 was set to cylinder 270.
Regards,Ruslan
..not Stalker but this is what Ruslan means.. L
Thanks Lauri! H^^
I had just such an arrangement of the engine, as on your plane.
You should definitely try to fly on Stalker !!! <=
Regards,Ruslan

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Re: Stalker Stunt Engines
« Reply #75 on: May 22, 2020, 08:49:42 AM »
Hello, friends !
Today I present to you our new CNC wooden propeller for the classic 4-2-4 Stalker 61 aerobatic engine. Many pilots have been using the Stalker 60 or Stalker 61 for a long time. We are happy to fulfill their wishes, and have started serial production of size 61 air propellers (9.95 see cube). The propeller is designed exclusively for Stalker sizes 60 or 61. Before production, the propeller was tested and was changed many times. As for Stalker 76 and 66, the propeller size 60 - 61 is also made of birch or beech, and after manual adjustment of the screw pitch and balancing, it is painted with automotive two-component acrylic clear varnish or white automotive two-component acrylic enamel. As on previous Stalker series propellers, the pitch of the screw has a non-constant size, it decreases from 170 mm to 140 mm. The screw pitch at 75 percent of the axis of rotation is 160 mm. The final finishing of the wooden surface of the propeller, the pitch of the blades, balancing, preparation for painting and painting by airbrush is done exclusively by hand, with great love for sports and for the athletes who will use the propeller.
This is a basic requirement for the production of all our products.
I wish you all a lot of good flights and good mood! 
https://controllineparts.com/stalker/192-propeller-60-61-stalker-stunt-engine.html
Regards
Ruslan Kurenkov


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