Other .25 size engines

The most popular .25 engine seems to be the OS FP, and now LA .25, but what about other .25's? Has anyone extensively tried the Magnum, TT, converted Norvel (plain or BB), Fox, etc?
I know some are only available in RC versions but venturi setups are not hard to obtain (buy or make).
Thoughts?

The Thunder Tiger available from Leonard is great!

I agree. My SSW TT 25 GP is easy starting, smooth, and consistent, and it has the useable power of my tricked out, very good Fox 35. I highly recommend it every chance I get.

The Mecoa 28 isn't a bad engine and fairly cheap. Not quite as light as the LA and FP because it is a BB engine. Run it in the hi-rev low pitch mode with a suction venturi and it preforms great.

Put it on a bladder and fly speed limit combat

>The Mecoa 28 isn't a bad engine and fairly cheap. Not quite
>as light as the LA and FP because it is a BB engine. Run it
>in the hi-rev low pitch mode with a suction venturi and it
>preforms great.
>
>Put it on a bladder and fly speed limit combat

Are any of these alternatives compatible with the FP/LA engine mounts?

I even considered a TT 36.

I have been using the ASP .25 with both the Jenn and the MVVS NVA's. I couldn't be happier, but then I am not an expert. I think the secret on .25's is to just experiment with fuel, props plugs and tanks until you find the combo that WORKS FOR YOU with Your planes. I have used these on Ukeys and recently on Twisters.Easy starting, economical and all the power I will ever need.

>Are any of these alternatives compatible with the FP/LA
>engine mounts?
>
>I even considered a TT 36.

If you are talking 20/25, then the Thunder Tiger 25 is a clone of the FP 25. It uses a true type venturi with the needle in front (my only complaint) but it uses a fully machined and balanced crankshaft (like the very early FP engines), has better plating on the cylinder, and parts are interchangeable (and cheaper). It is a drop in replacement for the FP

For the 35, 40 FP (or 40, 46 LA) the Thunder Tiger 40 is a clone and the Thunder Tiger 42 uses the same mount and shaft length, but is NOT a clone. This uses a different bore/stroke so parts are not interchangeable, but makes a very good engine in both side or upright/inverted mount.

The TT 25 should be a drop in replacement for the 25FP, which it copies. I've got a dozen or so 25's I originally acquired for SLC. They include LA's, TT's, Magnums, and a lone Irvine. I like the Magnum best for SLC, it's a few hundred RPM better than the others on the same prop and slightly more rugged. However, I think the Thunder Tiger is by far the sweetest of the bunch for stunt (in the right ship) and sport flying. Unlike the FP, it's still being made and venturis and NVA's are readily available and cheap. I think that you folks out there chasing that magic setup with the LA25 should look hard at the TT instead. I've got nothing against the LA's (I own several 46's and I love them), the TT is just a better made engine and of course, runs like an FP.
I found Bob's remarks regarding Mecoa interesting too. I bought a Mecoa 32 last year to put in my ARF Nobler on a whim, and quite honestly I'm in love with it. It's very light for a BB engine in this class (about 8oz.) and put's out gobs of power as long as you don't try to make it run like a Fox. It likes to run fast in a wet 2 stroke so you have to play around a bit with props to get acceptable lap times. I've settled on the Top Flite 11/4 Power Point, gives me 5.2 sec. laps and is cheap to boot. The best part was the price. They were going for $60 last year, but I talked the gal on the phone into selling it for an even $50...told her to keep the R/C carb and the too-heavy muffler. The second best thing about the 32 is that the Mac's 6650 muffler fits perfectly. I have several that I've used with the LA46's and FP 40's so that was a bonus for me. If you're looking for a modern replacement for older cast iron 35's for the classic designs and consider something like the Magnum 36 a bit of overkill, you might consider the Mecoa 32, it's really a fine engine. MTCW

...They were going for $60 last year, but I talked the gal on the phone into selling it for an even $50...told her to keep the R/C carb and the too-heavy muffler...you might consider the Mecoa 32, it's really a fine engine. MTCW

Jim, I read a thread somewhere a couple of years ago that said MECOA makes CL versions of their engines. Did you ask? Perhaps they still do.

George, I had not heard that Mecoa had C/L versions of thier motors, they weren't listed on the web site anyway. I was actually trying to buy the 28 but they were out of stock (no suprise there). I ended up "settling" for the 32. It's got that stange looking rectangular head, looks like a miniature ST 51. In spite of that, it's relatively light. Like I said before, I'm very pleased with it.

I have several Fox 25 pb engines, four bolt backplate, 5.5 oz. I think they were built from the 70's to the 90's. Out of production now. I used one on a Dumas Tomahawk, 325 Sq In. Zinger 10/4, 015 x 58'. Its a nice easy going sport flyer. They made a 19 similar, but the 25 is same weight, same mount.
But my all time favorite 25 is the 1950's Fox 25 3 bolt backplate. It's just under 5 oz, good 2-4 break, but hard to find at swap meets. I have one on a PDQ Flying Clown for OTS.
All of the above engines are convenient because the Fox 19, 201, 25, 29 and 35 all fit in the same mounts.
Happy Landings

>But my all time favorite 25 is the 1950's Fox 25 3 bolt
>backplate.

I took Fred K.'s advice and used a K&B28 Sportster on my Skyray that I used in beginner a few years back. Flew very nice with a Zinger 10-4 prop. One advantage is that it is a close fit to the Fox35 mounts (I used that Skyray for Fox racing and learning to fly stunt.)

>I took Fred K.'s advice and used a K&B28 Sportster on my
>Skyray that I used in beginner a few years back. Flew very
>nice with a Zinger 10-4 prop. One advantage is that it is a
>close fit to the Fox35 mounts (I used that Skyray for Fox
>racing and learning to fly stunt.)

Actually a 10/4 is kind of small for the K&B 28 it behaves like a long stroke motor and really likes larger props. I used one in an early hershey bar funfly against some potent Webra 32's and just for fun I ran a Davis Diesel head and an 11/7 M/A prop. I didn't win but got 3rd place to everyones suprise. Point is as a glow it likes 11/4 props and it will interchange with a Fox 35. You just have to shave to top of the mount slightly. Dennis

Hey.... John Brodak is releaseing a 25 sized motor.......if they are anywhere near as good as the 40's then I am sure there will be a newer option to the OS........

I just happen to have aquired a couple of Magnum GP-25s as part of a box-lot. Both are in very good condition, with RC carbs and mufflers.

Has anyone had any experience with them? I'd really like a starting set-up since they appear as if they are quite similar to the FP clones. If they are close, one'll go into my "Prowler".

Maybe I lucked up! Hope so.

Bigs

" What constitutes the dignity of a craft is that it creates a fellowship, that it binds men together and fashions for them a common language. For there is but one problem - the problem of human relations."

The early Magnums were made by Thunder Tiger in Taiwan and they were FP clones. These may be the ones that you have. Yes, by all means, use them.

Glad to see this topic raised as just a few days ago I was comparing specs on the .25s that Tower Hobbies offers.

Any comments on the GMS series they handle? Looks like an ounce-and-a-half heavier than the OS LA but has Ball Bearings and a much higher horsepower rating (0.85 @ 18,000 rpm vs 0.6 @ 15,000 rpm)...

>Glad to see this topic raised as just a few days ago I was
>comparing specs on the .25s that Tower Hobbies offers.
>
>Any comments on the GMS series they handle? Looks like an
>ounce-and-a-half heavier than the OS LA but has Ball
>Bearings and a much higher horsepower rating (0.85 @ 18,000
>rpm vs 0.6 @ 15,000 rpm)...
>
>
>Dennis

The GMS motors have not always received sterling reviews. Made in china, it seems that the quality has varied from excellent to horrible. This line was initially introduced by Jim Goad at Indy RC in the 80's and was dropped when that company was absorbed by Horizon Hobbies. Made a re appearence by MECOA to the same complaints. A lot of the complaints were on carb and P/L fits.
No one that I know ever bought one so I can't comment further.
dennis

>Glad to see this topic raised as just a few days ago I was
>comparing specs on the .25s that Tower Hobbies offers.
>
>Any comments on the GMS series they handle? Looks like an
>ounce-and-a-half heavier than the OS LA but has Ball
>Bearings and a much higher horsepower rating (0.85 @ 18,000
>rpm vs 0.6 @ 15,000 rpm)...
>
>
>Dennis

They are heavy, and the higher horsepower rating is not useable power. We aren't going to run them at 18,000 rpm in stunt applications, and horsepower will fall off drastically at lower rpms. They could certainly be made to run, but the weight difference alone takes me out of the picture.

The current issue Magnum XL .25/.28 are nice runners. I ran a .25 on a Pat Johnston "Stunt Trainer" with good results. RSM (Fox .35 size) tongue muffler, .250" venturi, ST clone NVA, 10-22GMA fuel and Taipan 9-4 worked well. Probably tried 10-3 and 10-4 APC's, but didn't clip either. Mike Haverly has run a .28 quite a bit, even tried it in his Oriental. Steve

Have had good luck with three Fox 25 BBs. Did not lap, so there was a lengthy breakin period of course. I think stock venturi ID may be too large for pure suction, but have had no probs with GRW chicken hopper tanks and motors run consistently well, even with stock nva. 8" props are best. Plan to test with bladder on 450 sq in combat ship for SL. Will get back with results...

LAST EDITED ON Jun-29-04 AT 02:03 PM (CDT)
 
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Virtually all of the 25 size engines are useable. Unfortunately we have some who are fixated on a certain motor and can't remove their heads from other parts of their anatomy and come up for air.
Often overlooked is the Enya 25 both in SS and BB versions. Mine is probably the steadiest runner that you'll ever use.
The fox 25 plain bearing has been mentioned, the newer BB version has not received much notice or development. Both are useable but not high on anyones list
The Norvels are well known in RC combat but seem to have been bypassed by the ultra conservative element of the C/L community.
Most of the Asian rim motors are very similar in running chacteristics and all can be made to run pretty much the same.
The only other criteria is to have one that is idiot proof something that THE DIRT can run and not embarass himself.

Edited per Dans request

Dennis,

Idiot-proof is good, I depend upon this sort of product on a daily basis.

Please capitalize "Dirt" so one and all will readily acknowledge that you're pickin' on me.

Nice use of smiley faces...

I heard it once said that anyone who believes they can make something idiot-proof doesn't fully understand the ingenuity of idiots.
No disrespect intended to anyone, and the smiley face left off for Dan.