I am lookimg at the RCS 140 gasser for a 1/4 scale aerobatic, need opinions, looks and sounds like a great gasser? thanks wc

It is a great little engine. I have one in a H9 Edge at 12-1/2 lbs. plenty of power for most things but will not do full 3D stuff. If you can keep the weight down you will be surprised at the power of this engine. Mine turns an APC (wide) 17X8 prop @ 8400rpm.

What about the RCS for more power???

The RCS140 is a nice engine for 10 lbs. and under planes. Mine is on an 11 lbs. plane and vertical is certainly not unlimited. The idle is great but there is a large RPM step about mid throttle that could be a problem for aerobatics requiring throttle management.

I would say the power output to be in the area of the older vintage 120 glow engines. It is not on par with the newer YS, OS, Saito 120's.

I run a 16-10 APC prop on it. Don't know the RPMs with this prop.

You might also look at the MVVS 1.6 gasser. I have seen good reports on it. It is a little heavier, but it is also a larger displacement engine.

The RCS 180 is too heavy for it's power output. It is close to the 2.4 engines.

I don't have any trouble with throttle management with my 140

jemo wrote:
"I don't have any trouble with throttle management with my 140"

Did you swap carbs? If so, what carb did you use?

I have had two of these engines and both exhibited large RPM gain when the disk transitions past the high speed orifice.

No, I didn't change carbs. Two things may be the reason. #1, a lot of tweaking. #2, a throttle curve set on my radio.
Other than that I don't know why.

EXPO IS A WONDERFUL THING

snotlocker wrote:
"EXPO IS A WONDERFUL THING"

Expo won't get it, snot. I have a JR 10SXII and can manipulate the curve somewhat, but I would need a 10X with multipoint mixing (eight points) to get the bump programmed out :disappoin

Don't get me wrong, I really like the engine. This little quirk and some mixture weepage around the head is all that keeps this from being a great engine.

The first engine weeped severly and Mike Dooley replaced it with the one I have now. The new one weeped also and Mike suggested some HondaBond to seal it. That helped, but it still weeps some.

i take it weeping is the same as a little leak ? at the head ?
if so mine dose this also ....ill try hondabond

Correct... small leak.

Six flights today after HondaBond cured and the leak seems to have stopped.

Engine is coming on pretty good now after ~2.5 hours running. Need to go to higher pitch prop. 16-8 is not enough now.

after a gallon ,im running an 18x8 on a ten pound world models extra 120 ..
it is getting more power with time ,