mmattockx

I am looking for a fairly hot 25 size engine for a small pattern plane. There doesn't seem to be much available anymore that I have been finding. So far, I have found the OS 25FX and the TT 25Pro. Are there any other decent choices? Which of these two would be strongest on the muffler and which on a tuned pipe?

Thanks,
Mark

soarrich

My Feedback: (98)

I have a DD with a OS 25DF engine with a pipe does maybe 110mph.

NikolayTT

Unless you have offcial restrictions for the size, the .25 is not the best, I believe it is
better to get .35 where are the same weight you will get significant extra power,
in fact .35 is the same .25 where the displacement is made a big bigger and that
is just couple mm wide and tall.

Also, for those displacements Super tiger and especially MVVS are well known
to be very good ones at much lower cost than OS.

paulhenley

i would do a sing and dance for the supertiger engines, they are not the cheapes but the do scream (not to shure about their throttle range, especially for the likes of a pattern ship). But reccommend that you stay well away from the mvvs engine, i had a delta with a old 25fx (standard muffler) in it, and bought a mvvs 28 (blue head) with matching minipipe (claimed to swing a 9*8). I tried the engine with a an apc 9*8 and with the same master airscrew 9*6 that was on the old 25 and with either prop it was left standing compaired to the old os 25. The mvvs was a really bad runner too, would never hand start with ease (os, first flick every time), it wouldn't tickover for too long (always needed a throttle input) and is generally just a crap enigine (in my view), it does however have a big carb and blue head and blue prob hub/washer which looks nice .... but thats about it

i'd get the OS 25 or if your not limited get the 32sx, they are a 100% safe bet , even when bought off ebay i'v never had a bad one, they never need tuning (top end somtimes if your squeezing reevs out of one), start off a flick and never cut .


henley

rmenke

My Feedback: (13)

mmattockx:

The O.S. 32 seems to be a decent small block engine with rpms in the 16-17k range. Lifespan seems short, but thats about normal for all OS engines. This engine on a cut down winged Viper Q-500/Jett pipe was the only thing out there that could stay on the same lap (almost asame lap ) as my beloved Jett 35 for around 5 years locally. The Jett 35 is a small block 25 pumped to a 35, result is wonderful, more poop that most 46's in a sneeky 25 frame. Expensive?, well, sort of. If you factor mine is now 6 years old and still running as strong as ever after 5 years of practice and racing, its cheep compaired to replacing the stuff good for a year or so. The 35 still goes to the races as a backup for a Jett 60LX powered thingy that is current king of the hill flown at about 1/2 throttle so as to not be excessive. Most full out Q-500's can not keep up wfo. Spend the money and be overjoyed for years. Second place is simply first LOOSER. enjoy

MJD

My Feedback: (1)

A .28 that turns a 9-8? 9-8 is a reasonable load for a .40. That claim seems out to lunch, I'll bet that engine wants a lot more revs than that. An 8-6, 8-7 maybe.

vertical grimmace

My Feedback: (1)

I think for your pattern plane the OS .25FX or .32 would be the best choice. You can always add a pipe but I do not think you want Max RPM for pattern. Are you trying to go fast or have torque for vertical? I would even throw out the Saito .30 or .40 engine for this application. The .40 is basically the same size as the .30 and both are close to the size of the .25's. I love my little .30 Saito.

evan-RCU

OS .32...... one of the best engines ever made...

freakingfast

My Feedback: (3)

I'll second that!

combatpigg

My Feedback: (3)

Amen, my OS .32 can't exactly be called short lived. Did I ever mention here that I use castor?

mmattockx

I should have mentioned it is an old style ballistic pattern ship, so yes I want it to rip. I am not flying pattern with it, just blasting around and having fun with a small smooth flying aircraft.

Thanks for all the replies, guys. I was looking at weights and the OS 32 does seem to be a winner here. I have a TT 36Pro, but it is a couple ounces heavier than the 32 for only a touch more power. From the sound of it, the 32 would like a Jett muffler?

Mark

vertical grimmace

My Feedback: (1)

Yes, Add a Jett muffler and it seems the magic prop is an 8-8. I am sure someone else will chime in here.

misterpanda

Since you're seeking 25-sized engine suggestions, have you checked out the GMS .25?. It's economical, well made and (mine) runs quite well. Good luck.

Misterpanda

bob27s

My Feedback: (19)

What airframe is it ?

SSGSPEEDMAN

anyone every used the TT Pro .36?

I was thinking about using that with a header and tune pipe on the new Great Planes .25 Spitfire.


Kevin

H5606

Why is it that major manufacturers' two-strokes that had round cylinders seem to be migrating torward square designs? I like the appearance of the GMS engines and their option of a remote or carb mounted high-speed needle. Any other feedback on the GMS .25 or .32 with the needle valve located on the carb?

vicman

My Feedback: (10)

Back to the original options of the FX vs TT. I have both and would pick the FX over the TT every day of the week. However I love my MVVS .28 and would choose it over the FX. That said, being outside of the original option the OS .32 is a wicked good motor. If you got the extra $ get one! Then put a Jett pipe on it

Red B.

One quite hot .25 engine is the [link=http://www.westonuk.co.uk/index_021.htm]Weston W 25[/link], which is Webre Speed 25 customized by Weston UK and sold under their brand name. Performs really well and seems to last a long time.

Another good engine with about the same performance is the MVVS 4,2 GFS/R-ABC-RC Combat.



A rather more exotic engine that outperforms both of the engines above is the Novarossi N528F.