Author Topic: New Stalker ST66 RE Engine. (Read 3973 times)

Randy Cuberly · « **on:** May 03, 2018, 09:08:22 PM »

Just received my new Stalker ST 66 RE engine from Tom Dixon. It's Beautiful as expected.

I wanted to mention that Tom has been extremely helpful in the purchase and very tolerant of my questions and has offered much information.

I ordered the engine day before yesterday and it arrived this evening by priority mail.

I'll probably put a little bench time on it tomorrow but it will be a while before I actually get it in an airplane!

Too many airplane projects going on right now! Oh well, I'm sure it will keep well!

I plan to run it on No Nitro fuel like my Belko engines.

Randy Cuberly

Scott Richlen · « **Reply #1 on:** May 04, 2018, 06:24:19 AM »

Randy:

Can you tell us more about it? Weight, what prop you'll use, what plane you'll power with it? Is this the first one you've bought or have you bought this engine previously (if so, what did you like about it, what did you not like?)

Thanks,
Scott

Randy Cuberly · « **Reply #2 on:** May 04, 2018, 08:55:51 PM »

Quote from: Scott Richlen on May 04, 2018, 06:24:19 AM

Randy:

Can you tell us more about it? Weight, what prop you'll use, what plane you'll power with it? Is this the first one you've bought or have you bought this engine previously (if so, what did you like about it, what did you not like?)

Thanks,
Scott

Hi Scott,
I really didn't say much about it because it was just discussed at length by many people on a thread here jus a couple of days ago.
I really didn't have much to add to that except that it's a beautiful hunk of aluminum and steel!

Run down the page a few threads and you'll see it. Very nice engine and I've wanted one for a long time!

That thread got a bit side tracked but basically has a lot of information about this engine!

I called an it LT66 above in this thread but that was a typo! It should of course be ST 66. I seem to be making more and more of those lately.

Old stiff fingers and a slowing down brain I guess! As for a prop I'll probably start with a 13.5-6 Bolly two blade

Randy Cuberly

Scott Richlen · « **Reply #3 on:** May 05, 2018, 05:43:44 AM »

Okay, I found it. Thanks!

Ruslan Kurenkov · « **Reply #4 on:** May 05, 2018, 08:17:56 AM »

Quote from: Randy Cuberly on May 03, 2018, 09:08:22 PM

I plan to run it on No Nitro fuel like my Belko engines.

Randy Cuberly

Hello Randy
I congratulate you on the purchase of the excellent Stunt engine.
Belko engines, like the Stalker engines, do not require nitromethane, but in very hot weather when air is very discharged I always added 1.5% nitromethane to fuel (82.5% methanol + 1.5% nitromethane + 8% castor oil + 8% synthetics (Graupner Aerosinth).
Regards
Ruslan

Lauri Malila · « **Reply #5 on:** May 05, 2018, 09:35:02 AM »

Hi Ruslan,

Speaking of Graupner Aerosynth oil, do you know the difference or have you perhps made comparative testing, between Aero Synth and Aero Save oils? I like Aero Save because it keeps my engine very clean, but I also know from experience that it does not work at all with Retro Discovery engines (my engine has a ringed piston). Maybe different chemistry..?
Sorry for slight off topic.

Lauri

Randy Cuberly · « **Reply #6 on:** May 05, 2018, 01:07:40 PM »

Quote from: Ruslan Kurenkov on May 05, 2018, 08:17:56 AM

Hello Randy
I congratulate you on the purchase of the excellent Stunt engine.
Belko engines, like the Stalker engines, do not require nitromethane, but in very hot weather when air is very discharged I always added 1.5% nitromethane to fuel (82.5% methanol + 1.5% nitromethane + 8% castor oil + 8% synthetics (Graupner Aerosinth).
Regards
Ruslan

Thank you for the information Ruslan.

I didn't mention it before but I actually did add 1.5 to 2 % Nitro to my fuel for the Belko engines during the summer here in Tucson AZ since the temperatures even in the morning here can easily reach over 100 F., and 108 to 110 later in the day! It definitely helped especially with the very good running long shaft .56.
I'm not sure the graupner Aerosynth oil is available here in the US but I typically use Klotz Lubriplate, with a small amount of castor added. Typically 18% total oil!

Do you have a recommendation for propellers in a 62 to 65 oz airplane.

Thanks,
Randy Cuberly

Ruslan Kurenkov · « **Reply #7 on:** May 05, 2018, 02:09:36 PM »

Quote from: Lauri Malila on May 05, 2018, 09:35:02 AM

Hi Ruslan,

Speaking of Graupner Aerosynth oil, do you know the difference or have you perhps made comparative testing, between Aero Synth and Aero Save oils? I like Aero Save because it keeps my engine very clean, but I also know from experience that it does not work at all with Retro Discovery engines (my engine has a ringed piston). Maybe different chemistry..?
Sorry for slight off topic.

Lauri

Hello Lauri
Synthetic oil Graupner Aerosinth is actually a synthetic oil for 2-stroke engines produced by Fuchs Titan (Germany) under the order for Graupner. Me and my friends, this 5 pilots from Ukraine ordered this oil for 5 years in a row. For engines, Stalker is the best, the most ideal synthetic oil. When using this synthetic oil on Stalker engines, Belko engines, Ratro Discovery engines - in general, and never was carbon accumulated at all. Never. With any number of flights. For five years I personally used this synthetic oil in 2000 flights. When disassembling the engine to replace the bearings, I did not observe the deposit when inspecting the piston and cylinder head. The piston was absolutely clean and light, like a new engine.
When using synthetic Motul 2T Micro oil on the Stalker 76 engine, it is necessary to perform a complete disassembly of every 50 flights, the carbon must be cleaned from the top and cylinder head. For Stalker 66 - 100 flights. When using synthetic Clotz oil - also every 50-100 flights it is necessary to disassemble the engine to clean the carbon.
Synthetic oil Fuchs Titan Aerosinth 3 (previously Aerosinth and Aerosinth 2), as reported by Graupner is no longer available for sale. Graupner decided to sell only the finished fuel on the basis of this unique synthetic oil. Last year I used Synthetic Motul 2T Micro oil on Stalker 76 and disassembled the engine for cleaning the carbon deposit 7 times - every 50 flights. This is very unacceptable. When using synthetic Aerosynth oil, I did not remove the engine at all and did not disassemble it during the whole season - it's 350 -400 flights.
Synthetic oil Aero Save, I never used.
Please write a link to this oil, and where it can be bought.
Please tell us why this synthetic oil is not suitable for Discovery Retro engines.
I really want to open here on the forum topic on synthetic oils for 2-stroke Stunt engines.
If this topic is interesting for F2B pilots and someone will support me then I will open a separate topic for discussion.
Many thanks for a good question.

Vitalis Pilkionis · « **Reply #8 on:** May 05, 2018, 03:03:33 PM »

It seems that Fuchs do not produce Aerosynth oil anymore. I have found this info here:

http://www.modelbouwforum.nl/threads/aerosave-van-fuchs-uit-productie.232730/

Fuchs unfortunately no longer makes oil for glow plug engines.
See Fuchs' answer below:
Thank you for your interest in our products.
Unfortunately Aerosave and Aerosynth 3 are no longer listed in our product program and we can not give you an alternative product. We apologize for any inconvenience.

Ruslan Kurenkov · « **Reply #9 on:** May 05, 2018, 03:12:45 PM »

Quote from: Randy Cuberly on May 05, 2018, 01:07:40 PM

Thank you for the information Ruslan.
Do you have a recommendation for propellers in a 62 to 65 oz airplane.

Thanks,
Randy Cuberly

Hello Randy
Recommendations for using the propeller for Stalker 66 from me personally and from the main test of the pilot of the company Stalker on engine 66 (Andrei Sopelniak, Kiev, Ukraine) are the following.
The propeller material is wood, birch.
Diameter of the propeller 350 mm
The pitch of the propeller is only variable.
At a distance of 170 mm from the axis, the pitch is 110 mm
At a distance of 140mm from the axis, the pitch is 140mm
At a distance of 110 mm from the axis, the pitch is 170 mm
A propeller with a constant pitch of 150mm and a diameter of 350mm is an average option (not sporty) only as a hobby.
Such propellers (after CNC) will soon appear on sale.
I will report on the forum.
Regards
Ruslan

Ruslan Kurenkov · « **Reply #10 on:** May 05, 2018, 03:24:20 PM »

Quote from: Vitalis Pilkionis on May 05, 2018, 03:03:33 PM

It seems that Fuchs do not produce Aerosynth oil anymore. I have found this info here:

http://www.modelbouwforum.nl/threads/aerosave-van-fuchs-uit-productie.232730/

Fuchs unfortunately no longer makes oil for glow plug engines.
See Fuchs' answer below:
Thank you for your interest in our products.
Unfortunately Aerosave and Aerosynth 3 are no longer listed in our product program and we can not give you an alternative product. We apologize for any inconvenience.

Hi Vitalis
In fact, this synthetic oil can be bought.
A week ago, our representative, from Controllineparts was in Germany at the Graupner exhibition. One of the questions about cooperation was the purchase of synthetic Aerosinth oil for our Stelker engines. Representative Graupner offered us this oil at 17 euros per liter when buying a minimum batch of 50 liters.
Officially, on the Graupner website and on the Fuchs website, this synthetic oil is not for sale.
We will buy only so. We have no other options. Stalker engines work fine all season without carbon deposits only on this oil.
Regards
Ruslan

Randy Cuberly · « **Reply #11 on:** May 05, 2018, 04:27:19 PM »

Quote from: Ruslan Kurenkov on May 05, 2018, 03:12:45 PM

Hello Randy
Recommendations for using the propeller for Stalker 66 from me personally and from the main test of the pilot of the company Stalker on engine 66 (Andrei Sopelniak, Kiev, Ukraine) are the following.
The propeller material is wood, birch.
Diameter of the propeller 350 mm
The pitch of the propeller is only variable.
At a distance of 170 mm from the axis, the pitch is 110 mm
At a distance of 140mm from the axis, the pitch is 140mm
At a distance of 110 mm from the axis, the pitch is 170 mm
A propeller with a constant pitch of 150mm and a diameter of 350mm is an average option (not sporty) only as a hobby.
Such propellers (after CNC) will soon appear on sale.
I will report on the forum.
Regards
Ruslan

Ruslan,
Thank you very much for the propeller information. From what you said I assume that you or someone there has plans to obtain CNC equipment capable of manufacturing the propellers you described. If this is correct please notify me if possible when they would be ready for sale. I would be interested in obtaining several of them!

Thanks,
Randy Cuberly

Lauri Malila · « **Reply #12 on:** May 06, 2018, 03:08:33 AM »

Quote from: Ruslan Kurenkov on May 05, 2018, 02:09:36 PM

Please tell us why this synthetic oil is not suitable for Discovery Retro engines.

Ruslan,

Both AeroSave and AeroSynth are Fuchs products. I have used Aerosave since early 90's with with similar experience than you with Aerosynth; absolutely zero carbon residue in piston/cylinder group or plug. Even as little as 5% of Aerosave in total 20% oil (rest being castor) is enough to keep places clean.
But Retro (.60 & .76) will not run well with it. Even with synth/castor blend there was massive detonation issues.
It would be interesting to know what causes these problems as at the moment I use same or even higher (trapped) compression ratio and same type of head with titanium umbrella without problems, only difference being Dykes ring vs. ABC construction, so the detonation cannot come from compression/combustion process. My guess is inferior load-carrying ability that leads to metallic contact in quite tightly fitted piston/cylinder group.
Also, the piston alloy was not very good especially in earlier Retro's. I know that Stalker uses much better piston alloy (RSP), even that alone may explain the difference.
About availability, as they both are in Fuchs/Graupner product range, you can ask from same supplier. But I also expect problems in availability in near future.
Would it be possible to buy the Aerosynth from you for testing? If someone could bring is a few litres in Landres, for example..?

Regards, Lauri

Doug Moon · « **Reply #13 on:** May 06, 2018, 11:49:41 AM »

Hello,

Not trying to derail the thread here but a question about retro oils. My brother runs the Retro 76 and the 68. He uses sig FAI fuel. Half syn half castor 20%. It runs good but extremely sensitive to fuel amount or it will overrun. 1/8 oz extra and it could over run on 8 minute time limit. What mix do you recommend for best run? Overall % of oil and % of castor vs syn? Brands?

Thank you

Doug

Ruslan Kurenkov · « **Reply #14 on:** May 06, 2018, 01:22:09 PM »

Quote from: Randy Cuberly on May 05, 2018, 04:27:19 PM

Ruslan,
Thank you very much for the propeller information. From what you said I assume that you or someone there has plans to obtain CNC equipment capable of manufacturing the propellers you described. If this is correct please notify me if possible when they would be ready for sale. I would be interested in obtaining several of them!

Thanks,
Randy Cuberly

Hi Randy
The manufacture of propellers for Stalker 76 at the CNC was started by us in the spring of 2017 (earlier propellers were produced only by hands). During the past year, we tested the propellers, after the tests we made changes to the production. At the moment, the production and sale of two types of propellers with a pitch of 170 mm under standard weather and with a step of 180 mm for hot, discharged air are fully established. diameter of 360mm. This type of propeller with variable pitch, which decreases with increasing diameter, was specially designed and tested by Sergii Solomianikov (Controllineparts), a pilot of the Ukrainian national team, only for the Stalker engine. This propeller does not fit under Discovery Retro 76. Conversely, the propeller from the DR-76 does not fit the Stalker 76 engine. These are completely different engines.
This month, the first batch of propellers for Stalker 66 will be produced at the CNC. Earlier these propellers were produced in a very small amount (10 units per year), only by hands and only by one person, Andrii Sopelniak, Kiev, Ukraine. This propeller will now be produced in any quantity on the CNC. The shape of the propeller and steps were selected experimentally for several years. I will certainly inform you about the beginning of sales.
Regards
Ruslan

Ruslan Kurenkov · « **Reply #15 on:** May 06, 2018, 01:56:00 PM »

Quote from: Lauri Malila on May 06, 2018, 03:08:33 AM

Ruslan,

Both AeroSave and AeroSynth are Fuchs products. I have used Aerosave since early 90's with with similar experience than you with Aerosynth; absolutely zero carbon residue in piston/cylinder group or plug. Even as little as 5% of Aerosave in total 20% oil (rest being castor) is enough to keep places clean.
But Retro (.60 & .76) will not run well with it. Even with synth/castor blend there was massive detonation issues.
It would be interesting to know what causes these problems as at the moment I use same or even higher (trapped) compression ratio and same type of head with titanium umbrella without problems, only difference being Dykes ring vs. ABC construction, so the detonation cannot come from compression/combustion process. My guess is inferior load-carrying ability that leads to metallic contact in quite tightly fitted piston/cylinder group.
Also, the piston alloy was not very good especially in earlier Retro's. I know that Stalker uses much better piston alloy (RSP), even that alone may explain the difference.
About availability, as they both are in Fuchs/Graupner product range, you can ask from same supplier. But I also expect problems in availability in near future.
Would it be possible to buy the Aerosynth from you for testing? If someone could bring is a few litres in Landres, for example..?

Regards, Lauri

Hi Lauri
Thanks for the info and thanks for the good question for discussion.
I know for sure that Yuri Yatsenko, the manufacturer of DR-76 and DR-68 engines, used Aerosinth (Fuchs-Graupner) as a synthetic oil. He told me this personally. And once this synthetic oil company Graupner stopped selling, then Yuri, and I, too, without this, oil began to accumulate carbon deposits on the piston. Your situation with detonation is not clear to me. According to your engine, you should contact the manufacturer. I think that 20% of the oil is very much, you should use 18%. And add a gasket (or two) under the head of the bob to increase the combustion chamber and reduce the compression ratio, especially in cool weather.
Synthetic oil Aerosinth manager Graupner promised us to deliver next month. If the oil is delivered to Ukraine, I will certainly pass you for tests of 2 liters through Sergii Solomianikov in Landres for the World Championship.
Regards
Ruslan

Lauri Malila · « **Reply #16 on:** May 06, 2018, 03:35:39 PM »

Ruslan,

Sorry, I was not clear enough.
My bad experience with Retro Discovery + AeroSave oil dates back to more than 10 years ago. That time I flew a lot with .60, first with 5/15% Klotz/castor mix without problems. Then I changed to Aerosave/castor mix because of good experiences with piped engines earlier (OS, Irvine, PA). However, Retro did not like Aerosave at all. So I changed to Motul, it was recommended by Italian Retro users and it is easily available. I also delivered quite a lot of Motul for Yuriy and Andrei, untill they found a source in Ukraine. Retro .60 is not so critical about oil, so I had no issues with Motul, but when I changed to bigger .76 Retro, carbon problems re-appeared, just as you explained earlier.
It is still a small mystery why AeroSave did not work, but I'm not alone with this experience. For that reason I'm curious to know what the actual difference between AeroSave and AeroSynth is.
I have no personal experience with Stalker engines and if there would be issues with AeroSave. If you want to test it, just let me know and I'll send you some via Sergey.

Cheers, Lauri

PJ Rowland · « **Reply #17 on:** May 06, 2018, 07:23:41 PM »

Wow.. its interesting to see different setups.

I found the .66 to be the same as the .76 and
61s..
I found noone ever ran the correct pitch. I SAW many in the 5.5" range but in my testing these engines produce power in a lower rpm range. 6700 to 7300 launch. So for nice lap times I ran minimum of 7" Pitch. On anything from a 10 to a 13" diameter. My preference was 11.75 x 7.25 2B
Oil I found 22% mix of 11% SYNTH and 11% A grade castor

More oil let it run cooler and allowed for Nitro which i enjoyed at 10%.

Randy Cuberly · « **Reply #18 on:** May 06, 2018, 07:35:42 PM »

Quote from: PJ Rowland on May 06, 2018, 07:23:41 PM

Wow.. its interesting to see different setups.

I found the .66 to be the same as the .76 and
61s..
I found noone ever ran the correct pitch. I SAW many in the 5.5" range but in my testing these engines produce power in a lower rpm range. 6700 to 7300 launch. So for nice lap times I ran minimum of 7" Pitch. On anything from a 10 to a 13" diameter. My preference was 11.75 x 7.25 2B
Oil I found 22% mix of 11% SYNTH and 11% A grade castor

More oil let it run cooler and allowed for Nitro which i enjoyed at 10%.

Yeah I think different setups can work on most engines with the right approach. One thing I want to do with this set up however is run no nitro or very low nitro. and try to keep the inside of the engine very clean! Typically a lot of synthetic only oil will help with that. I know that even 5% castor in my PA's means cleaning the carbon from the top of the piston and head about every 50 to 60 flights. Too bad Castor is so dam dirty because it does keep the temp very stable!

I recently began running a ROJett 67 (long Stroke) which also wants to run (albeit with a lot of power) in the 6600 to 7400 RPM range. It definitely needs about 6.5- to 7.5 pitch props or even more.

Randy Cuberly

Ruslan Kurenkov · « **Reply #19 on:** May 07, 2018, 03:53:37 PM »

Quote from: Lauri Malila on May 06, 2018, 03:35:39 PM

Ruslan,

Sorry, I was not clear enough.
My bad experience with Retro Discovery + AeroSave oil dates back to more than 10 years ago. That time I flew a lot with .60, first with 5/15% Klotz/castor mix without problems. Then I changed to Aerosave/castor mix because of good experiences with piped engines earlier (OS, Irvine, PA). However, Retro did not like Aerosave at all. So I changed to Motul, it was recommended by Italian Retro users and it is easily available. I also delivered quite a lot of Motul for Yuriy and Andrei, untill they found a source in Ukraine. Retro .60 is not so critical about oil, so I had no issues with Motul, but when I changed to bigger .76 Retro, carbon problems re-appeared, just as you explained earlier.
It is still a small mystery why AeroSave did not work, but I'm not alone with this experience. For that reason I'm curious to know what the actual difference between AeroSave and AeroSynth is.
I have no personal experience with Stalker engines and if there would be issues with AeroSave. If you want to test it, just let me know and I'll send you some via Sergey.

Cheers, Lauri

Hi
Thank you for the information and the offer to test the synthetic oil of AeroSave. I will be very happy to test on Stalker 76 and Stalker 66 this oil.
We did a lot of tests with different oils on Stalker engines.
The best and most ideal was the oil Aerosinth (Fuchs Titan, blue).
https://www.oeltitan.de/spezialitaeten/modellbau/
To completely clean the engine of coal deposits, only 5% of this oil and 11% of castor oil were required.
8% of this oil and 8% of castor oil is added only when it is cold for a low viscosity of the fuel and good through the fine filter fuel filter.
Motul Oil does not clean the engine. This oil we added earlier, too, when it's very cold and the castor oil becomes very viscous.
I heard the AeroSave air but our representative Fuchs in Ukraine did not provide it. I will be very glad to test and give your feedback on the forum.
Please write a link where you can buy oil from AeroSave.
I think Randy will not take offense at us for talking about oil.
Regards
Ruslan