need engine recommendation

I'd like to know what you guys think about 20-25 size engines that are currently available.
Before everybody jumps in with a recommendation too soon, here is what
I'm looking for:
light weight good fuel economy good power-to-weight ratio
I am a big fan of the OS FP 20 and 25 engines for precisely these reasons. I know a lot of guys don't like them because they are "trainer" engines, but they actually have a very good power to weight ratio because they do not have the added weight of ball bearings. Not only that, but their fuel economy is excellent.
My stash of FPs is gradually wearing out, so now I'm looking for something new. I had the pleasure of running a new MDS 18 the other day, and it was great, although I suspect that it eats a lot of fuel, judging from the mess on the side of the plane after 5 minutes. I've also been impressed with the K&B 28 when I ran one a few years ago. Are they still in production?
Anyway, I know I will not likely find an engine with the same power-to-weight ratio and incredibly good fuel economy as an FP, but I'd like to know what you guys think. Except for an 061 last week I haven't bought a brand new two stroke engine in 10 years, and now I'm looking for something good to put on a New Era that I am going to build.
Robbie
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On Wed, 25 Feb 2004 15:56:01 -0600, Robbie and Laura Reynolds

I think Thunder Tiger's .25 GP is a good match for the old OS FP.
Plain bearing, so light weight and moderate power.
Seems to me I had one on a combat plane and was satisfied with it.
For a little more zest with not a lot more weight, there is the TT .36 Pro or an OS .32 FX. Both have bearings and are heavier than the FP/GP models.
                    Marty
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The .32SX is a screamer of an engine. Got one pulling my Uproar .40 and it is more than powerful enough for the job. Very good running engine too.
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Dan
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I like the Norvel .25, very light weight, good power, but have paid no attention to fuel consumption. It's in a PBF, where every flight is an adventure and every landing a nightmare.
Phill

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Ball bearings actually add very little weight to an engine on their own. Most of the weight gain comes from building the engine more robust to handle the extra power that usually comes with ball bearing engines. Ball bearing engines can be just as light as plain bearing engines if power wasn't a consideraton.
Look at the K&B 40 BB engines compared to the OS LA series. Same weight but more power. Same with Fox.
In the .25 class I would go with the Norvel for weight and power.
What are you going to do with it?

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Paul McIntosh wrote:

I've been planning to build a New Era, but I don't want to put the 20 FP on it. For those who don't know, this is a small pattern type plane from the 70s, found in the RCM plans catalog. I definitely know how to build a plane that comes out lighter than the published specs. Generally my planes are anywhere from 10 to 30 percent lighter than what's called for in the construction articles, and that's usually due to wood selection, staying away from epoxy almost entirely, and leaving off unnecessary parts that add weight but little else to the airplane. I also never use paint or fabric.
I like 4 strokes, but I think that my OS 26 would weigh the plane down too much. I have really come to appreciate what a lightweight engine can do for a plane, even if it has only 80% of the power of the "top of its class" engine has. The extra weight just makes the plane more sluggish. If you don't have the weight, you don't need the power anyway. But I fear that the 20 FP just wouldn't make this plane perform. (And my 25 is already busy in a BD-6.)
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Webra Speed .32 (well, one out of three ain't bad) Dr.1 Driver "There's a Hun in the sun!"
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You might check into a GMS .32. Same size as their .25 but bored out. LOTS of power. I have been haunting Ebay myself getting together a stash of FP engines lately, mainly for a twin engine project but decided to go for twin .30FS engines instead. The .25 and .15 FP engines I got wont go to waste, however!
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Fubar of The HillPeople wrote:

So you're the one who is running the prices up!
Those are some of the greatest engines ever made.
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Mwahahahaha!!! Actually, I have only purchased 2 each of the .25 and .15 sized FP engines so far. I put one of the .15FPs on a Hyperbee I just built. Perfect engine for the plane. One of the .25FPs is going on a Super Sportster 20 I am building as preparation for the twin engined SS 40 I plan to build soon. Hmmm.... I might need more engines soon... Mwuahahahahaha!
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