Twister Engine

[Chris Fretz]

What engine sounds better for my Twister? I have a Testors Series 21 .40 on it now, or does a LA .40 sound like a better choice?

[Dave_Trible]

I'd prefer the McCoy you have on it now myself.  You'll run lower RPM with more matza balls than the LA at higher R's.  You'd use a 10-6 or 11-5 or 11-6 on the Mac or an 11-4 ( likely) on the LA.  We've tried  a '5' and '6' trying to get more thrust from the LA but they just aren't what the FPs were.  I'd stay with the McCoy.  Use at least 24% oil.

Dave

[Chris Fretz]

I'd prefer the McCoy you have on it now myself.  You'll run lower RPM with more matza balls than the LA at higher R's.  You'd use a 10-6 or 11-5 or 11-6 on the Mac or an 11-4 ( likely) on the LA.  We've tried  a '5' and '6' trying to get more thrust from the LA but they just aren't what the FPs were.  I'd stay with the McCoy.  Use at least 24% oil.

Dave

I do like the old Series 21 (heavy though). I was just looking for an excuse to use the LA... I've been running 29% oil with 5% nitro in the McCoy with the good old 10-6, maybe I should give the 11s a try.

[Dave_Trible]

What you might try;  on profiles I've had two or three sets of mounting holes for a few different engines to experiment.  If you can do this you will be able to compare the engines directly without changing anything else and give you the opportunity to get more use from your various engines.  Much can be learned about the two types of engines and what an assortment of props will do.

Dave

[Chris Fretz]

What you might try;  on profiles I've had two or three sets of mounting holes for a few different engines to experiment.  If you can do this you will be able to compare the engines directly without changing anything else and give you the opportunity to get more use from your various engines.  Much can be learned about the two types of engines and what an assortment of props will do.

Dave

I messed around with one LA 40 I got from craigslist last year but I had no end of trouble with it.  It would run for a second an shut off,  I messed around with it on the airplane for a wile an then I was ready to hurl it into the weeds. Took it home put it on the bench but same thing.  I took the head off of it an they had the sleeve oriented in the wrong direction.  Put it back together an it stayed running.  Put back on the airplane an it ran for ever but didn't seem to have much power.  Maybe I had the wrong prop on it or it is just junk.  I got a couple others I was pondering trying but I can't seem to bring myself to get away from the Testors lol

[Tim Wescott]

If I were going to step outside your choices to recommend an engine for a Twister I'd say either a 25LA or a 46LA -- both of them have some stunt-run magic that the 40LA just lacks.  I haven't flown them, but folks who have just love the Enya 25 and 30.

Pay close attention to whether the 40LA was reworked -- a lot of the bad rep it has is because it's just not as good as either a 40FP or a 46LA, but more of the bad rep is because it came out when people thought that everything needed to run like a Fox 35.  So there were some popular mods to the thing to try to make it work more like a Fox 35.  So if it's an old CL engine you have to (a) know whether the engine was reworked, and (b) whether it was reworked well enough to still be in good shape.

A 25LA will only work for a really light Twister -- I have a 53 ounce Fancherized Twister that does pretty good on a 46LA.

[Chris Fretz]

If I were going to step outside your choices to recommend an engine for a Twister I'd say either a 25LA or a 46LA -- both of them have some stunt-run magic that the 40LA just lacks.  I haven't flown them, but folks who have just love the Enya 25 and 30.

Pay close attention to whether the 40LA was reworked -- a lot of the bad rep it has is because it's just not as good as either a 40FP or a 46LA, but more of the bad rep is because it came out when people thought that everything needed to run like a Fox 35.  So there were some popular mods to the thing to try to make it work more like a Fox 35.  So if it's an old CL engine you have to (a) know whether the engine was reworked, and (b) whether it was reworked well enough to still be in good shape.

A 25LA will only work for a really light Twister -- I have a 53 ounce Fancherized Twister that does pretty good on a 46LA.

Hi Tim,

It wasn't  reworked it has the RC carb on it. It was from a guy flying RC airplanes. What makes the 40LA so different from the 25 or 46LA? The inside different? Its a same they suck cause you see them everwhere unlike the 25 an 46 (of couse huh)

Im sure my twister is heavy...

[Chris Fretz]

Pay close attention to whether the 40LA was reworked -- a lot of the bad rep it has is because it's just not as good as either a 40FP or a 46LA, but more of the bad rep is because it came out when people thought that everything needed to run like a Fox 35.  So there were some popular mods to the thing to try to make it work more like a Fox 35.  So if it's an old CL engine you have to (a) know whether the engine was reworked, and (b) whether it was reworked well enough to still be in good shape.

Do you know the mods to do that? Is it successful? That sounds pretty cool and right up my alley!

[john e. holliday]

I have several LA 40's and learned to not move the needle unless there is a drastic temp change.   Also I use Top Flite Power Point props,  11-4's.  Tried others but these work on my planes.  Don't know why but the 46 seems to be an easier engine to use from day to day and have used 11-5, 10.5-4.5 and various other prop.  Right now using Zoar 11-5 on LA 46 in my Ringmaster Imperial.   The LA 25's, some need muffler pressure and the others run great on uni-flo tanks.  Also these guys are about to convince me to try electric.

[Tim Wescott]

Do you know the mods to do that? Is it successful? That sounds pretty cool and right up my alley!

I think the best mod is to not mess with it.  Or sell it on eBay and use the $$ to buy a 46.

People have gotten them to work -- see John's comments.  I was going to suggest an APC 11-4 or 11.5-4, but you might want to try John's Top Flight Power Point 11-4, 'cause it works.  If you can figure out how to use the search function on this forum the subject has been discussed a LOT.

[Chris Fretz]

I have several LA 40's and learned to not move the needle unless there is a drastic temp change.   Also I use Top Flite Power Point props,  11-4's.  Tried others but these work on my planes.  Don't know why but the 46 seems to be an easier engine to use from day to day and have used 11-5, 10.5-4.5 and various other prop.  Right now using Zoar 11-5 on LA 46 in my Ringmaster Imperial.   The LA 25's, some need muffler pressure and the others run great on uni-flo tanks.  Also these guys are about to convince me to try electric.

Can I have your LA's when you go electric?

[Dennis Moritz]

La 40s work. Run them where they like to run. At that rpm. They're cheap these days. La46s often sold at a premium. If the engine doesn't keep a steady rpm or cuts out, something is wrong. Trouble shoot. It's not the engine design     


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[Brett Buck]

Do you know the mods to do that? Is it successful? That sounds pretty cool and right up my alley!

   No modifications! Or at least very minimal. You don't want it to run like a Fox 35.

   Brett

[Chris Fretz]

If I were going to step outside your choices to recommend an engine for a Twister I'd say either a 25LA or a 46LA -- both of them have some stunt-run magic that the 40LA just lacks.  I haven't flown them, but folks who have just love the Enya 25 and 30.

Pay close attention to whether the 40LA was reworked -- a lot of the bad rep it has is because it's just not as good as either a 40FP or a 46LA, but more of the bad rep is because it came out when people thought that everything needed to run like a Fox 35.  So there were some popular mods to the thing to try to make it work more like a Fox 35.  So if it's an old CL engine you have to (a) know whether the engine was reworked, and (b) whether it was reworked well enough to still be in good shape.

A 25LA will only work for a really light Twister -- I have a 53 ounce Fancherized Twister that does pretty good on a 46LA.

Oddly enough I do have a 40FP laying around.

[Tim Wescott]

I'd start with the FP.  The nice thing about the FP and the LA is that they're the same size -- so you can build the plane to fit one, and then try the other.  At best you'll find that you have two nice engines for Twister-sized airplanes.

[Dennis Moritz]

LA40s are essentially budget manufactured Fp40s. Cast crank vs forged. 4 Phillips head bolts vs 6 sockets. Plastic backplate vs aluminum. I read that some LAs lack a boost port. I also read that the crank bushing is shorter in the LA even tho casting is the same length. Tower 40s a near FP clone top them both. A superior chrome cylinder vs nickel plate. The LA40 should be set up run like an FP.


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[Chris Fretz]

One of my LA40 has a aluminum backplate that looks factory, did some of them come aluminum or the early ones? I'm guessing the FP backplate is the same as they look the same?

[Tim Wescott]

Lots of folks got FP backplates and stuck them on their LAs.  But it may have come from the factory that way.

[Dennis Moritz]

FP40s, Tower 40s, LA40s, can acquit themselves well. Do a 2 x 2 break. Put out the power. As any model engine it might need some tuning to the plane for optimum performance. Venturi, fuel, prop, head gaskets, exhaust flow, all interact, putting the 2x2 break where you want. Lee machine will make a venturi to fit, drill the hole as you specify. I like Lee's venturis. They're taller than the stock OS. Seems to me, it straightens the air some on it's way to induction. OS makes two venturi sizes. S(mall) and L(arge). Small is 6mm, large is 7mm. I think. .283 is Large. Definitely. Remember these venturis were chosen to work with the OSFP needlevalves, needles thinner than the Supertigre clones. If you use a Supertigre type needle you will restrict choke area. Keep that in mind when working with venturi openings. FP40s, LA40s, Tower 40s, can work very well in stunt applications as stock. Typically they put out usable power at a higher rpm than dedicated stunt engines. Their sweet spot probably narrower in the rpm range. Darn good compromise when considering price and general application.

[dave siegler]

I am going to say this.  Use what you have.  its paid for.  

Figure out what is wrong with the LA 40, you will learn something in the process.

The FP 40 and the LA 40 run well and strong but too fast for some and at the higher levels of stunt. It is tricky to get them to run slowly in a reliable way.   So set it where it is happy,  even running too fast they will get you through the first steps.

Then reevaluate where you want to go.  An LA 46 will drop in later if the airplane lives.  

I had an FP 40 on a twister, it was fine.  Long lines (68 feet)  flat (11.5 x4) prop.  Still pretty fast, faster than I really wanted.  But  getting it to slow down did not work every time.  So I switched to longer lines, flatter prop and let her her wind up. It was OK for my level, never an issue with line tension.  

My local advanced fliers said it was fine, just a little fast.  Told me to quit screwing with it and fly it faster for a while till I got the basic pattern down.  

[Brent Williams]

You might try Doug Moon's approach to FP40's and just let it run away.   
Install an APC 11x3 and let it operate in the RPM range it was designed to be operated at.

http://stunthanger.com/smf/engine-set-up-tips/fp-40-does-adding-a-head-shim-help-tame-the-run-away/50/

I used to prop mine so they can run away all they want yet still a usable speed for stunt.

I used stock motor, stock OS CL muffler maybe just cut off the end a little to open it just a tad.

Then use some junky Omega 10% rc fuel 18% oil synthetic and an APC 11x3 set with just a 2s beep on the ground.  It would run 2/2 everywhere with just a small slower beep on the upwind side. 

It worked well, speed was the same everywhere it went.

[Dennis Moritz]

Smaller venturi slows the FPs down. Head gaskets soften the break. Free flow tongue muffler. 10.5x4.5 APC helps. Running Powermaster 50/50, 22%,10%. Very nice. I ran a Tower 40 on a Magician, Galaxy and many Twisters. Magician weighed 32ounces. .273 Venturi, three head gaskets, free flowing tongue muffler, the engine was sweet. Galaxy does the pattern no problem. These planes are not too fast. Even tho on the small size for these engines. Galaxy is ridiculously easy to fly. Could be because it's been doing the pattern for the last ten years. 60' lines eyelet to eyelet. On the other hand I had a great flying Prowler, something of a porker, 46 ounces. Needed to take ALL the head gaskets out, run a .283 venturi. Nice combo after believing my friends who kept saying pull out all the head gaskets, open up the venturi, etc. Engine broke in the right places.

[Dan Berry]

Clayton Berry flew the daylights out of a Twister with  a Tower 40 and a APC 10.5 x 4.5 prop.

[Chris McMillin]

Once you've flown so many cases of fuel through that McCoy 40 it won't start anymore you could change to one of the OS motors these guys are talking about. Until then I doubt you would benefit at all by the change.
Practice. More flights. A coach. That's what one needs to progress. Burn that fuel.
(I had a buddy that had a hand-me-down Trophy Trainer with a Series 21 40 on it from Bob Whitely, ran like a truck. We used 10% nitro in it with no problems too.)
Chris...

[Chris Fretz]

What is a good lap time? Fast time?

[john e. holliday]

Don't worry about lap time until you get the plane and engine combo where they are happy and you are comfortable.  But, most pilots shoot for a time between 5.0 to 5.5 seconds on 60 foot lines.  If you do a search you will see that also on lines up to 65 foot lengths.  I've seen guys not do good because of their dependence on lap times.  When you fly enough and use a tach then you can time your laps.  A good tach helps if you keep a log and know your equipment.

[dave siegler]

You might try Doug Moon's approach to FP40's and just let it run away.   
Install an APC 11x3 and let it operate in the RPM range it was designed to be operated at.

http://stunthanger.com/smf/engine-set-up-tips/fp-40-does-adding-a-head-shim-help-tame-the-run-away/50/

yup exactly.