Folks:

I am looking for details on the most fuel efficient engines in the 90-and larger class. I am looking for a low rpm, high torque engine, either glow, or glow-converted-to-gas, that produces 2 hp or more. Two stroke or four stroke, does not matter: just looking for a long endurance engine.

Please email me directly, if possible: [email protected]

Suman
Lawrence, KS

There have been several posts on here about the Webra 120 being fuel effecient, I have one that is barely broken in and can only say that it is very smooth running and idles really well and has a good reputation for being light and powerful. Runs best on 5% nitro. 3.2 HP

Have you tried a Davis diesel head for your engine, or looked into converting an engine with a Davis diesel head?
In the past we have run a couple of these, and they really do (almost) double run time.
We flew an FP .40 with one and, it made the 40 min. round trip with a reg. sized tank- granted, this was in a LARGE modified sailplane, but we had a lot of fun taking it on road trips!!

Jetts

Gentlemen:

I have used diesels for years. I am looking for engines that rival, or better diesels in fuel consumption. The problem with diesels is also that they are not made in the large sizes I am interested in.

Thanks for the info, and please keep the responses coming.

Suman

Lots of luck guy, if you find something like that let me know.

Jetts

Mvvs makes .61 diesel that has great power. Capable of swinging large props ~ 15 inch with ease. A large diesel produced by a manufacturer.

bobi

Maybe you can share the fuel consumption of your engine with us.

I ran my OS 160 FX at WOT with a 17X8 prop at 9400 rpm on a eight oz tank for 5 minutes 20 seconds after I had about 1/2 gallon thru it. This was peaked rpm and therefore less fuel consumption than when tuned to fly.

Brian

Turning a 17x8 at 4000 rpm, the 60-size PAW diesel ran about 2.5 minutes on one ounce of fuel. I was disappointed, considering my Irvine 40 can turn a 12x6 APC at 6000 rpm for about 15 minutes on one ounce.

Suman

I'm one of the guys saying the Webra is fuel efficient. I have never measured it. I fly mixed turn-around aerobatics. 15 minutes of flying uses about 10 oz of fuel.

suman, I think what you need is a gasoline engine. Take a look at the MVVS 1.6 petrol. If you're really energetic, and can accommodate a poor power to weight ratio, try a Ryobi four stroke trimmer motor. I think you need spark ignition and the ability to run lean A/F ratio. A tuned pipe may help the two stroke if tuned for moderate rpm. That would be a big long pipe for the MVVS.

A model diesel is different than an "regular" diesel. The fuel is not injected into the cylinder an there is no control of ignition timing. It's more like planed pre-ignition. :stupid:

If you're thinkin about the webra 1.20 and want to get maximum fuel economy, you could get a davis diesel head for it. They make a few of conversion heads for .90 and greater size O.S., supertigre, webra, rossi,and moki engines.