Will a stock OS 25 LA fly a Twister?

Does anybody have this setup? Wondering if a stock OS 25 would be enough for a Twister. (monocoated wing, sprayed fuselage). Looking to fly the beginner pattern on 60' lines. The plane is not built so I cannont give the weight. I know other planes would be more appropriate for this engine. But I am curious about this particular setup.

Some might say yes if you build it super light but, how often does that happen. Get an LA .40 and fly it on 65' lines.

LAST EDITED ON Nov-28-04 AT 06:14 PM (CST)
 
The LA 25 has a bit more power than a Fox 35, which has been used on many many Twisters. 9/4 or 10/4 prop. Adjust the venturi size to get the kind of speed and power you want.

Yes it will, though I use a 40 on a Banshee. I also chop 2 inches off the nose and add 3 inches to the fuse behind the wing. Changing to a slightly larger tail and it usually balances. It definatly has an excess of power which I stop down by using the smaller old CL muffler from OS and letting a big prop with low pitch run at a richer than needed setting.

The Twister though has a shorter nose already, so you may only need to extend the tail.

I've READ that the 25 flys twisters just fine, heck they're more power than a Fox 35. But I've got experience with the 40. When it goes lean, you definately know where the model is!

You know, after having just enough power on my Mustang to fly with a good Fox 35, ta heck with it. NO, if you need to ask, it ain't enough power. Get more power with the la or fp 40. When you KNOW you build light enough for the Twister, it that ain't gonna be a kit, then you can screw around with the 25.

A stock OS 25 has more power than a stock Fox 35?

Yes, swinging a 9x4 or 10x4 prop the os will have a higher power output. But it won't swing a larger, higher pitch prop that the Fox does. Then again, the Fox doesn't swing that bat too fast.

I would venture to say no. The FP 25 seems great on smaller planes (Ringmaster, flitestreak, etc size) It works great on my Tomahawk-it seems to have tons of usable power for that small, flapless 42 inch wingspan plane. I would be afraid a larger plane might be marginal on power, especially a flapped job. I just had that 'hawk out today, and again as always marveled how well the entire plane/engine package works, especially on a very windy day like we had this afternoon. I just don't think the power deal with the 25 would translate real well to the larger heavier airframe.

I would throw in my 2 cents for an LA 40 or 46, or magnum 36.

For the past year I have been flying two Twisters with ASP .25's on board. The .25's are strong enough to handle the Twister. Give yours a try. If not satisfied you can always go to a larger engine.I didn't need to.

Back when I was younger and flew better, I flew a Twister on a Fox 35 with a Zinger 11 x 5 prop and found it quite fine. So, if a modern 25 has more usable power than a 50+ year old 35, it should be even better.

>Does anybody have this setup? Wondering if a stock OS 25
>would be enough for a Twister. (monocoated wing, sprayed
>fuselage). Looking to fly the beginner pattern on 60' lines.
>The plane is not built so I cannont give the weight. I know
>other planes would be more appropriate for this engine. But
>I am curious about this particular setup.

Short answer: Yes.

Longer Answer: Keep the overall weight light, and if the necessary, try shortening lines a foot or two in 6 inch increments after you have it trimmed out.

V/r

LAST EDITED ON Nov-29-04 AT 08:00 AM (CST)
 
I once built a Sig Twister from a Kit. I don't know how much the airplane weighed. I experemented with several engines. The OS 25LA flew my Twister better than the Fox 35 did.

Comparing the 2 engines is like comparing apples to oranges. The OS gets its power from high RPM's. An OS 25 LA with a 10x4 prop is about the same as a Fox 35 with a 10x6 prop.

One of the local stunt clubs thought they could race 25 sized engines against our Fox 35 stunts. They just couldn't keep up.

I'm sure an OS LA .25 with no boost port has alot less power than a Fox .35.

For stunt you might be talking apples and oranges if the Fox is 424 and the OS is a rich 2 stroke then I can see where you would say the .25 has more power. Tweek the needles and the Fox walks away.

A friend of mine had a nice flying kit built Twister with an OS FP .40

Must've been the prop. Try a 7x6 on the .25, they'll honk. The fastest Fox Stunt I've ever seen was one of Bud Bodzioch's - about 80mph with something like a 8x8 prop, on a Combat plane. Some people can supposedly get them up to 100mph on a racer and the right prop.

Glenn Lee was running some Fox Stunt 35s in a beginner speed event some time back, and I think they got them up over 100 mph. I think that is stretching things for that old fox. I get plenty of speed out of them in the Foxberg event. I don't ever recall clocking one for speed though. Just go out and run as hard as you can and hope for a win. Lots of fun.

The 25 FP will pull the Twister fairly well with the right prop.

Bigiron

I think combining Glenn Lee and Stock Fox 35 in the same sentence is risky!!

Fellow TreeTown member,

He really loves them!!! I get to run against him at the Sig contest in the Foxy Hazel race occasionally. I haven't flown that event for the last three years due to some health problems, but am looking forward to butting heads with him again .

Bigiron

Back in 1993, I flew a modified (profile) Twister with a K&B 28 for power. It flew the Beginner pattern just fine (enough to win Beginner at the big SIG contest). So I would think the OS25LA would be quite close.

If you were flying the full pattern, I would recommend something larger, like a LA40.

The discussion of LA25 and FP25 vs the Fox 35 has cropped up a number of times on this board. Alan Hahn and I have played with all of these engines and have definite opinions. I believe the LA25 and FP25 are quite useful engines and MAYBE close to a good Fox 35 in useful power, IF you find the prop that makes them happy. For us, it was much easier to find a prop that makes the Fox 35 perform the way we like and make stunt friendly power. BUT, I also do not usually run Fox's in profiles. They sometimes have strange characteristics when positioned sideways. When vertically mounted, they are wonderful basic stunt engines.

Alan, any further comments?

Fred

my kit built twister is powerd by a stock thunder tiger gp25 and has plenty of power (it has been crashed and repaird once) so it is not real light but the tt25 a 9-5 apc and a clunk tank on 55 foot lines and handles the wind better than my magnum/st51 combo. i run the 25 along the lines of the brett buck fp combo (cant by the fp20 easly here in aust.) and if i was a fraction of the word smith of your own bad boy stunt author i would rave about this combo (these boys should be apreciated!) having said that i also have a la25 and is a much softer running motor out of the box ( just a novices opinion )
stephen

I'll add my .02 here since I had a Fancherized Twister that started out with the OS 25FP and switched to the FP 40.

Mine flew fine with the .25. You just cant let it get off to a rich start. It will also suffer some in the wind.

If you are just getting into the beginner pattern, I believe you will feel more secure with a 40 in front--especially if the twister comes in a tad bit heavy.

As your skill improves and you gain more confidence in your inputs and the plane, you wont have any trouble flying it with the smaller engine--I'de go with a forty--it will be better able to overcome your initial (over zealous) control inputs and power you out of some problems.

Just my two cents.

I also built a Twister that had a Fox 35, and then a 25LA. Both didn't have the power required to fly the plane really well. I switched to a 40FP and the problem was solved. Like Curt said if your planning on using the plane to teach you the pattern the 40FP or similiar is the way to go.

As a sport flyer, I often am flying both engines on models, one right after the other. Despite OS's claim of 0.7 HP for the FP 25 (and, I think the LA also), I would rate the stock Fox 35 as roughly comparable in power (Peter Chinn of MAN and other testers usually found c. 0.5 HP here, albeit at a lot lower rpm vs the OS) The OS FP 25 is on a foamie "combat trainer" type model with a single, Streak-type landing gear. It has about 450 square inches and a pretty thick airfoil, and pulls this model with authority. I was fortunate in scoring some original Y & O (not the more recent B Y & O) 10-4s at a Canadian swap, and this is what my FP 25 likes. I think the Y & O fully exploits its capabilities.

The two competing engines, of course, do their jobs in different rpm ranges, and with rather noticeable differences in smoothness. And noise too, with similar tonque mufflers often used on both.

I see that you are pretty close to sea level. So I would say if you have a 40 use it on the Twister. Use the 25 on a smaller plane. I have been watching John Bender fly the ARF Flite Streak with the Blue LA 25. Great combination, especially since he has built a new baffled tank for it. But, I know from experiance that planes and power plants fly differently in other than home location. Gold Brick flew fairly well at VSC, but, Hear in Kansas it is very twitchy. Later, -DOC:-)

> I see that you are pretty close to sea level.

Actually, we are flying at around 850-900 ft above sea level. People usually do not know that the Great Lakes are at about 600 ft or so. True, this does not significantly affect engine performance.

Where I fly is a Metropark called Stony Creek. It is about 26 miles from the center of Detroit. Certain parts of the Detroit metro area, mainly to the northwest, exceed 1000 ft altitude.

Twisters are THE stunt trainer (and cheap simple serious competition flyer in Advanced and P40) in my club. Abuse was heaped on me for a year and a half until I finally built one. (What a relief.) The ultimate mythic combo includes an FP40 with an extra head gasket, an apc 101/2x41/2, running on powermaster half and half %5. We use tongue mufflers with a lot of big holes and the larger venturi using an OS needlevalve. We add half ribs and lengthen the tale moment at least 11/2". (Sort of Fancherized.) The FP40 set up this way will do a wet 2cycle that breaks into a faster 2cycle. If runaway continues to be a problem the head gets a hemi perm.

The plane flies a bit fast but pulls well and handles the weird winds that blow at our field. One club member, a couple of years ago, scored real well in local contests using a stock fox 35 on a stock Twister. Talent will out.

I'm sorting out my Twister with an FP35. The FP35 runs o.k. using an old style fp muffler but runs away with the newer muffler. I proceeded to dork this plane first day out. Should be repaired by the weekend.

My flying buddy has used different FP40s on his for the last two years set up as above. Almost always finishes high up in advanced. It's an ugly looking bird, but he sure flies it well. The engine/airplane combination is consistent, sweet and snarly. I believe the plane and engine won P40 at Brodak and Garden State this past season.

My LA25 on an ARF Streak seems well matched. I run it close to flat out. Doing the beginner pattern nicely when I'm aligned right. Definitely an LA25 will not pull a Twister with similar authority.

>Does anybody have this setup? Wondering if a stock OS 25
>would be enough for a Twister. (monocoated wing, sprayed
>fuselage). Looking to fly the beginner pattern on 60' lines.
>The plane is not built so I cannont give the weight. I know
>other planes would be more appropriate for this engine. But
>I am curious about this particular setup.

25FP = the hot setup, far better than anything else I have seen on a Twister
20FP = pretty good
25LA = on the edge, if you ask me
25 baffle-piston = better build very light and fly in the calm

All 25's are not alike. The 25FP is a well-proven combination, very common around here. The LA seems to be noticably down on power by comparison.

Thanks for all the great input. It is much appreciated. Based on the nay's I think I will hold off on this combination at this time.