Author Topic: Stalker ST40RE 4-2-4 stunt engine. (Read 5910 times)

Chris Wilson · « **on:** May 15, 2011, 09:48:09 PM »

Hi all,
Just finished a search here and read all about the above engine but the 40 in this brand seems a bit rarer than the other sizes, and so is the information.

I have a chance to purchase a new old stock one and was wondering if anyone could state a comparable engine in terms of use and power.

Thanks.

PJ Rowland · « **Reply #1 on:** May 16, 2011, 01:08:21 AM »

I've been using the Stalkers for 11 years now. Good solid classic style engine run. I've run almost all they have made.

I do think In general the Stalkers are underpowered given other options out there. For example, I dont beleive the .40 is as strong as the Aerotiger .36 for one example.

I think the .51 is about as a good / strong as a ST .46
The .61 isnt that strong compared to other .60 sized engines out there. Ultimatley designed around FAI fuel and larger Dia props.

Setup is straightforward, I would just be very careful as to what you decide to build around it in terms of size and weight.

I think anything larger than a classic 500 sub 50oz model is to large to get the engine to work where it needs to work.

For example, well documented I run the 4-2-4 .61 lite RE in my Classic ships - Why not a .40? or a .51 ? they dont have enough guts for good solid performance. IMO

keys to good setup :

Right Prop for the engine.
Hot plug
No more than 10% Nitro
They like some Castor ( 5 - 8 % )and some Syth
2 Shims
Ready to go.

Gordon Tarbell · « **Reply #2 on:** May 16, 2011, 08:51:57 AM »

So even with 10% nitro they won't have the power ? I have been using a ST 51C/L (new style) and have a stalker 51RE that I got new . The stalker weighs less but I was hoping for the same power level as the ST. I always run at least 10% nitro some times more in my engines. Yes they suck alot of fuel but they run good. Sound like I might have to build something a little smaller for the stalker. I was going to put it in a Whitely Deringer(670"sq.)

Ted Fancher · « **Reply #3 on:** May 16, 2011, 09:43:36 AM »

Quote from: gordon tarbell on May 16, 2011, 08:51:57 AM

So even with 10% nitro they won't have the power ? I have been using a ST 51C/L (new style) and have a stalker 51RE that I got new . The stalker weighs less but I was hoping for the same power level as the ST. I always run at least 10% nitro some times more in my engines. Yes they suck alot of fuel but they run good. Sound like I might have to build something a little smaller for the stalker. I was going to put it in a Whitely Deringer(670"sq.)

PJ,

What happens if you add another head shim or two and run higher nitro? How much fuel do you ordinarily burn with a .51RE? I've always (roughly) considered fuel consumption to be somewhat predictive of power output (btu's and all that stuff) but must admit that some of the European style engines (like the metamorph .60 I ran in my Great American ARF-OFF ship(Windy/Brodak's big one whose name my old timer's disease as rendered unrecoverable) put out bunches of power with much lower fuel burn than I'm used to (and lower nitro % as well).

I've got a .51RE that has been aging in my cabinet that I'm considering putting in my updated .35 Gypsy (also aging above the Murphy bed) and would love to know a bit more about it before committing to building a new fuselage to suit the engine change.

Ted

Brett Buck · « **Reply #4 on:** May 16, 2011, 09:57:28 AM »

Quote from: PJ Rowland on May 16, 2011, 01:08:21 AM

I've been using the Stalkers for 11 years now. Good solid classic style engine run. I've run almost all they have made.

I do think In general the Stalkers are underpowered given other options out there. For example, I dont beleive the .40 is as strong as the Aerotiger .36 for one example.

I don't know about the other sizes, but several of the locals have run the Stalker 40RE with consistent and smooth runs, but feeble power. The RE version appeared to be particularly wimpy, like "less-than-a-Fox" wimpy. Gutted out lean, with a 10-6, and 5.5 second laps on a Nobler-clone wimpy. More nitro did not appear to help, and I don't know what else they tried. This is of course apocryphal but it was the same story for at least 3 different engines.

Brett

John Miller · « **Reply #5 on:** May 16, 2011, 10:18:14 AM »

I have to agree with PJ. I've been running Stalkers for a while, and really enjoy their consistency. They do seem slightly down on power compared to others, but once taken into account, will perform with great consistency, at least that's been my experience.

I tend to run FAI no nitro fuel with mostly synthetic lube. 0% nitro, 15% quality Synthetic, 3-5% castor is my prefered blend.

I'm using the ST .40 RE in my 620Sq. inch All American Eagle. Here in Salt Lake City, at our altitude, It's barely up to the task, but doable, while at Tucson, or lower, It does the job just fine. I may try tipping the nitro slightly here in Salt Lake. I run a Grish 9X6 3 blade, launching at about 8200. I use an RC plastic clunk tank set up as a uniflow.

I use an ST .51RE, which I consider Stalkers most versatile engine, on my version of Gordan Delaney's Pathfinder L.E. Never a problem either here at altitude, or lower, on the coast. I run the same style tank, and I like the Evo 11 X 6 prop on this 650 sq. inch, 65 oz design.

I've used a Stalker .61RE on my Legacy. I've recently retired the plane, but the Stalker hauled it around just fine. I'm considering running this engine on my new Biplane when it's finished.

Fuel usage, with the way I'm running mine seems a bit less than otherrs of the same size. Those I've seen being used with modifications, such as 10% or more nitro, head gaskets, larger venturi's, seem to use more fuel. Some seem to suffer in reliability, though not all.

It's my opinion that the Stalkers were designed to run their best with the Typical Eastern European style runs on no nitro. Changing the setup may make the engine more powerful, but also may affect other aspects of the run. At least, that's been my experience.

PerttiMe · « **Reply #6 on:** May 16, 2011, 10:26:15 AM »

So, with Stalkers it is a good idea to use a size or two more engine than with other brands?

And they work well with low or no nitro and fewer shims.

FLOYD CARTER · « **Reply #7 on:** May 16, 2011, 01:09:45 PM »

Stalkers come with a couple extra head shims in the box. I have two Stalker 51 RE motors. I installed the shims before I did anything else. I typically use SIG Champion fuel, 10% nitro and 50-50 oils (20% total). They both run just fine. I also run a T&L ST51, which is about equal to the Stalkers.

Floyd

Balsa Butcher · « **Reply #8 on:** May 16, 2011, 01:10:36 PM »

I've seen Gordan fly his full size Pathfinder at Whittier Narrows and it sure did not look underpowered to me. My Stalker .51 will be going into a 630" Brodak United. I think it will be a good match.

Brett Buck · « **Reply #9 on:** May 16, 2011, 01:23:34 PM »

Quote from: Pete Cunha on May 16, 2011, 01:10:36 PM

I've seen Gordan fly his full size Pathfinder at Whittier Narrows and it sure did not look underpowered to me. My Stalker .51 will be going into a 630" Brodak United. I think it will be a good match.

The one that Gordan and John have in their new Pathfinders ran pretty good - the *only* Stalkers I have ever seen run properly with decent power. I flew Gordan's airplane and it was excellent.

The 40RE did not run that way. The 61's have have seen have been either completely uncontrollable with gigantic venturis, or completely unpredictable in other ways. Brian Eather seems to have figured it out but I have seen nothing with frustration with them locally.

Brett

Alan Resinger · « **Reply #10 on:** May 16, 2011, 01:41:06 PM »

I've run Stalkers for the past few years and haven't had any problems with them. They have adequate power. My 66 flew my last of the very big Firecrackers with better power than when I had a RO Jett 67 in it. Now these were both running on mufflers and the Jett was running a 12.5 X 6 Eather 3B while the Stalker ran a 12.5 X 5.5 at about the same RPM. The Jett just didn't want to run the way I wanted and would have been much happier with a much lower pitch prop and a lot higher RPM. The 61RE has about the same power as a ST60 has but is a lot smoother running. I have 2 that have been built with different timing and they run just fine on 10% nitro with 18% all synthetic oil. I saw one of the Stalkers that Brett is referring to at Eugene last year and it was indeed set up wrong. Most run well if you don't get too large a venturi and get the right prop on them. On my 66 I run on FAI fuel now and use about 4.75 oz while the 61's use about the same amount of 10% nitro fuel.
Alan

Chris Wilson · « **Reply #11 on:** May 16, 2011, 05:13:55 PM »

This from the old Stalker Modusa site (http://www.stalker-modusa.com/index3.htm) -

Stalker 61 2/2 engine – not to be confused with over revving modified Schnuerle ported engines that need low pitched props. . If incorrectly propped, the 61 2/2 will run 4/2. Be patient, try different props until you find the right one that will work with your model and that gets the engine to run 2/2. The 61 2/2 engine runs at a lower rpm (7600rpm) than the other Stalker 4/2 engines (8200+). The other exception to the rule is the 40RE that runs around 9600 rpm (10-15% nitro) for an excellent 4/2 break run.

Fuel - 17% to 22% synthetic oil (Klotz is recommended) , no castor oil for Stalker ABC piston/liner. WE DO NOT RECOMMEND THE USE CASTOR OIL IN THE FUEL.

So it seems that the 40 RE is a bit of a wild card here with only 2º exhaust lead (whereas all the other engines in their range has 20º) and needs to be pushed a bit harder!

Thanks.

PJ Rowland · « **Reply #12 on:** May 16, 2011, 07:36:28 PM »

Ive tried many different configurations.

I had Oleg make me up some custom heads - Hi Compression Hemi for the .61 and .81 - Ive got custom venturis made up for them all, various thickness of Shims, plugs, props, nitro contents, oil contents.

Ted : I found more shims tend to make it blip into the 2 stroke a little earlier. Part of what Im trying to acheive is 4 stroking throughout the entire flight, in level flight and getting a little blip at the top of the outside loops, I find alot of setups tend to pop into the 2stroke during level flights into the wind. I want to avoid this. Like the pipe guys do.

I know for a fact the brian eather has his .61 running very well - he also runs 20% Nitro. I have tried 20% I would only go to that content when air is thinner like muncie will be. I typically run 10 - 13 % Nitro.

5 - 7% does nothing for me.

I can get perfect engine runs out of all my Stalkers. In fact the engine runs I acheived at the Nats with the Nobler .61 combination were put in print as " best engine run at the Nats "

I run them because the give flawless engine runs, depending on how you want it run, solid 4 stroke is acheiveable if you remember the torque range is low - I launch at 7100 - 7200 rpm for my .61 for a solid 4stroke lock in.
The .81 I run a little lower 6800 - 7000.

The problems occur with higher rpm to agressive with the switch, not always giving consistant speeds through manouvers. Ive seen guys try to get upward to 7800 - 8k and not have sucess they are designed with FAI fuel and a prop that will unload it quickly.

Running with modern props that tend to load the engine - and giving more shims and more nitro can compound the problem. with trying to get Launch RPM to high.

What I was saying is that I dont think the relative engine sizes to other manufactures are as powerful. Im not saying you can't fly them, For a few years I ran the .61 re on my normal sized ship. I then upgraded to the longstroke with more usable power.. Once I went to the .81 the difference was unbelievable. The constant speed, the power, the thrust were amazing. I remember thinking the 1st flight " This is perfect "

I've had similar expereince with the .76 but prefer the low down , low rpm high pitch prop setup of my .81. Granted the .81's I have are part of the 1st batch.

1 is one of the first test .81's Kaz minato from Stalker.
2 Are ex Kaz minato comp engines so I suspect the are not quite factory standard. I have no basis for that statement other than I also have a fairly new .81 recent batch that didnt want to run as smooth as my 2 comp version.

The .66 I found not to be as good as the lognstroke .61 edition I've spoken to others who have said similar - the reason you would go up in size is to go up in usable power, I found there not to be any advantage.

I dont agree with the statement the .61 is as powerful as an ST .60 I think its more like the worlds strongest st.46. A good St.60 is formidable. This is backed up by the fact my new Classic Gieseke Nobler runs the .61 Longstroke and will be at the US NATS - I urge anyone to come and look at its performance and make the judgement first hand.

I know Bob Gieseke for a while ran the st.60 in an earlier version of his nobler so it will be facinating to chew the fat over my setup with him. Perhaps twist his arm to fly it and get a good idea of how it stacks up.

One more thing to add : I really dont think people generally get the pitch correct for the timing and Rpm of these engines. It took me a little while to establish the exact pitch required to run these where I want them. My Gieseke Nobler for example runs a Eather 12 x 7 3/4 Undercamber.

I have tons of eather props ( 20+ ) ranging from 11 3/8's - 13 " Diameter to 6 3/4 - 9 " Pitch. My usual setup for the .81 is between 12 x 7 3/4 " Pitch - 8 1/2 " pitch. depending on Thrust requirements and ambient air.

I realise this is quite high, even Kaz agree's 7" pitch is standard, and puts that on his website.

PJ Rowland · « **Reply #13 on:** May 16, 2011, 08:41:42 PM »

I just wanted to add one more thing :

I consider myself in no way an engine expert of the Ilk of a Randy smith, Brian Eather, Brett Buck or Walker.

What I have suggested above is only what works for my setups. My process of what works is fairly rudimentary possible crude compared to others.

I would during a normal decent day of practice get between 35 - 45 flights in a session.

Leading up to a nats - For example - leading up to the US Nats I usually take time off - I will have 11 days off prior to leaving where I will be full time practice, I will arrive in the US 12 days prior to the event starting.

If I get good weather : Which is usually possible during this time of year :

23 Days of practice : Even if Im slack and Im only getting 35 flights a day in : 800 odd Flights in a 3 week period leading up to the contest.

I have in the past and will do again, modify, alter, change one thing, try it fly it, make a note of its cause and effect. By process of shear weight of practice flights and process of elimnation I find what works for me, and what doesnt.

Im afforded the luxury of countless flights and a good solid fitness regime that allows me to fly consistantly multiple flights, over multiple days without much in the way of loss of fatigue, mental concentration.
My Fitness regime is Control line aerobatics based, at a gym 2 Nights a week, which would consist of Lots of shoulder work, repitition of flying the pattern with a 3 - 5 kg lightweight dumbell, doing multiple reverse wingovers, loops, maintaining form and 45 degree attitude. Lots of core work with a swiss ball and core machine - Cable crossover work, Running. 20 Minutes in the pool to help the shoulder recover, 30 minutes in the Sauna with a basic maths and problem solving book- to allow me to do mental excersises to train my mind to stay focused during extreme fatigue and exhaustion.

Like now for example I also suppliment that training once I get home with watching for about 1 hour repeats of US nats flyoff's. Currently Im watching alot of the 2004 Flyoff with brett, Ted, Paul, billy and Bob. What this does is help to put you in the moment. There is strong correlation between pre visualisation of events and beign able to control nerves, and improve success, supplimental to practice alone.

Infact whilst I digress - I can sight a famous sports study done a few years ago at a US College. This is an abridged copy.

A famous study was conducted by the University of Chicago many years ago with basketball players to prove the power of visualization. It consisted of three basketball teams. Team 1 were instructed to go to the gym every day for one hour and practice throwing free throws. Team 2 spent an hour in the gym every day, followed by a visualization period whereby they envisaged themselves successfully shooting hoops. No physical practice was allowed. Team 3 were instructed to play no basketball whatsoever neither mentally or physically for the month. When the month had passed, the three groups were assessed to determine if their shooting had been affected. The team who had neither mental nor physical practice had dis-improved. The team who engaged in just physical practice had a 24% improvement rate. Amazingly the team who had only visualized themselves throwing successful free throws had improved by 23%.

This study proves that you maximize your success by visualizing your free throws at every available opportunity. It is great way to maximize the results of physical practice.

So to conclude, never rule out the power of your mind.

Weight of numbers gets the job done for me, I appreciate those like Brett whom can have only 50 flights a year and have such a solid knowledge base that they know what needs to be done to acheive a purpose, and can Win major contests..

I have a good working knowledge of many aspects of Stunt, I know if I want to do something - for example add tip weight, move leadouts for a specific purpose, I will do that.. However what I DONT know and I will happily admit to ,is the extent to get it right.

I've heard accounts of guys saying to other fliers for example " add .4oz of tip weight and move the leadout 1/4" back and you will be right " It would take me 3 - 5 flights to establish an ideal setup for tip weight adjustment and leadout position adjustment, I would arrive at the desired outcome but not off the 1st attempt. EVER.

Even when I get it right, I like to tinker and find out what if I try this, or that.

Gordon Tarbell · « **Reply #14 on:** May 17, 2011, 12:15:44 AM »

on the 40RE with 10-20 fuel mix (10nitro/20syn oil) would the bolly 10.5x5 be a place to start or is this still too much pitch for this engine in a(Gieske/uhp)nobler?

PJ Rowland · « **Reply #15 on:** May 17, 2011, 12:31:29 AM »

It would come down to how much load the bolly applies to the 40.

I dont find exessive pitch effects load as much as Dia does.

Brett Buck · « **Reply #16 on:** May 17, 2011, 09:16:09 AM »

Quote from: PJ Rowland on May 16, 2011, 08:41:42 PM

Weight of numbers gets the job done for me, I appreciate those like Brett whom can have only 50 flights a year and have such a solid knowledge base that they know what needs to be done to acheive a purpose, and can Win major contests..

And in this case, I will freely admit that I am no expert in Stalker engines. I did assist several others in their troubleshooting efforts, and that's what I base my observations on. I offer it for what it may be worth, but not as an ultimate judgement on the topic.

Brett

John Miller · « **Reply #17 on:** May 17, 2011, 09:24:48 AM »

Please note, the .40RE can still deliver the goods, though it may need to have a slightly different set up. I'm flying a 620 sq. inch All American Eagle, (basically a Novi lll) at about 50 oz's. The altitude I fly at is 4600 ASL. I'm using a Grish 9 X 6 3 blade, and even though, at my altitude it is a little labored flying the pattern on 0% nitro, it will do the job. When I go down in altitude, using the same fuel, the engine does just fine.

What I'm trying to say is that it's not a super weak sister, needing lot's of modification to do the job. I've flown agianst other competitors with modified Stalker .40RE's. They made the modifications trying to get more power, and in most of the cases, they weren't getting the runs, or the power to make me want to switch from my stock version, running FAI fuel.

I've also used a stock .40RE in a Vector 40, with very good runs, and good power.

I see no need to mess with the engine to power a Nobler. It should do the job fine as is. The prop is important, I use a 9X5-6, 3 blade, or a 10 X5-6, 2 blade.

The best feature, IMNSHO, that the Stalkers have, is the quality of run, and the consistency, run to run. Chose your engine size considering the size and weight of the plane you'll be mounting it in. Rather than trying to make modifications to try and get more power out of the engine. Most I've seen modified were basically ruined engines.

PJ Rowland · « **Reply #18 on:** May 17, 2011, 07:21:08 PM »

Brett:

My statement about you being able to fly 50 flights a year was not in any way a negative one. I mentioned it as an endorsement on your skills as modeller, with both engine and trim setup.

Whatever the the engine, Stalker, PA, Saito, FP's, Rojetts, - You do have a fantasitc working knowledge of engines so I would not turn my nose the other direction if you or anyone else suggested something. Once you know how to Use a fork ,the brand is irrelivant.

I was making commentry on what worked for me, and how I arrive at solutions - Apropos sighting your example and being envious.

Walter Hicks · « **Reply #19 on:** May 17, 2011, 08:13:33 PM »

Gordon Delaney has an .81 that he enlarged the venturi .328 I believe and said it was a whole new animal. It is in a
740 sq in wing plane and is said to do well.

Allan Perret · « **Reply #20 on:** May 17, 2011, 09:16:39 PM »

Quote from: PJ Rowland on May 17, 2011, 07:21:08 PM

Brett:

My statement about you being able to fly 50 flights a year was not in any way a negative one. I mentioned it as an endorsement on your skills as modeller, with both engine and trim setup.

Whatever the the engine, Stalker, PA, Saito, FP's, Rojetts, - You do have a fantasitc working knowledge of engines so I would not turn my nose the other direction if you or anyone else suggested something. Once you know how to Use a fork ,the brand is irrelivant.

I was making commentry on what worked for me, and how I arrive at solutions - Apropos sighting your example and being envious.

I can usually adapt to a different brand of fork pretty quick.

But I have been known to struggle with Stalker's, Saito's, FP's, Double Star's, Enya's; you name it.

PJ Rowland · « **Reply #21 on:** May 18, 2011, 12:40:00 AM »

Yes the .81 is phenominal. I have heard of Gordon's success. It has incredible low down torque.. I do not have a Rojett .76 on pipe, but I'd love to compare back to back.

You certainly need a variety of Venturies to find the best setting.

Ive got 10 custom made venturies for the .81 ranging from .265 - .395

.325 sounds pretty reasonable - Id have to measure what Im running at the moment.

Brett Buck · « **Reply #22 on:** May 18, 2011, 08:11:13 AM »

Quote from: PJ Rowland on May 17, 2011, 07:21:08 PM

Brett:

My statement about you being able to fly 50 flights a year was not in any way a negative one. I mentioned it as an endorsement on your skills as modeller, with both engine and trim setup.

I certainly didn't take it as an sort of slight.

Brett

Air Ministry . · « **Reply #23 on:** May 19, 2011, 12:49:26 AM »

According to the tech spec sheet , the 40 RE has a 10 mm shaft .
The 40 SE through to the 51s have 12 mm.
So theres a thing .

PJ Rowland · « **Reply #24 on:** May 19, 2011, 07:32:15 AM »

Matt : try up to .81 - 12 mm Shaft.

Brett : Ok mate, just wanted to be sure.

Author Topic: Stalker ST40RE 4-2-4 stunt engine. (Read 5910 times)

Walter Hicks