RCU Forums - Engine for Piper cub

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Engine for Piper cub

Hi all,
I've started the build on a BalsaUSA 1/4 scale Piper cub. I'm still trying to decide what engine to use. I pretty much want to use a gas engine. Who out there have used a gas engine on this model? Could you tell me the brand of the engine, how well it pulls the cub, and how much modification it took to fit it to the airframe. The ideal engine for me would be gas with little modification to the airframe and completely covered by the cowl with only vent holes in the bottom for cooling air flow.

Cheers,

Dan

RE: Engine for Piper cub

Evolution makes a nice gas engine that would fit well in the Cub cowl, the 26GT. It will turn an 18 inch prop (scale diameter for 1/4 scale), weighs about 32 oz, makes 3.8 hp, and costs about $400. The carb sits in front of the cylinder, and a Pitts-type muffler would get the exhaust behind it, so the cowl would stay holes-free. Anything around 23-26 cc will have plenty of power to fly the plane, a G20ei or G-23, or G-26 Zenoah would also be good engines, but require a hole for the carb. The G20ei (electronic ignition) is on the small end, displacement-wise, but it makes as good, or maybe better power, than the G23, which has a magneto. G23's aren't available unless you can find a used one, it was upgraded to the -26.

RE: Engine for Piper cub

How about a conversion gasser? weed whacker or chainsaw? a 31 CC should be more than plenty....

RE: Engine for Piper cub

Quote:

ORIGINAL: khodges

Evolution makes a nice gas engine that would fit well in the Cub cowl, the 26GT. It will turn an 18 inch prop (scale diameter for 1/4 scale), weighs about 32 oz, makes 3.8 hp, and costs about $400. The carb sits in front of the cylinder, and a Pitts-type muffler would get the exhaust behind it, so the cowl would stay holes-free. Anything around 23-26 cc will have plenty of power to fly the plane, a G20ei or G-23, or G-26 Zenoah would also be good engines, but require a hole for the carb. The G20ei (electronic ignition) is on the small end, displacement-wise, but it makes as good, or maybe better power, than the G23, which has a magneto. G23's aren't available unless you can find a used one, it was upgraded to the -26.

Thanks, I've been looking at the Evolution also. Do you know if a pitts muffler is available for it? I was also looking at the RCS 140 with the rear exhaust port as a possiblility. The G20 looks like it would mostly fit except that the carb would probably be sticking out the cowl. It is suppose to be equivalent to a 120. I want this cub to fly scale and if possible not hack up the cowl, so as you suggested the evolution might be a good choice. What little I've read about the evolution 26 here on RCU hasn't been very positive. I've also have seen very little mentioned about the RCS 140 as far as reliability and performance.

Dan

RE: Engine for Piper cub

Quote:

ORIGINAL: cochinito77

How about a conversion gasser? weed whacker or chainsaw? a 31 CC should be more than plenty....

How about it? Can you be more specific?

RE: Engine for Piper cub

i think a nice homelite 25cc or ryobi 31cc would be very nice. they are cheap to convert and dont use hardly any fuel. the 31cc ryobi is nice, if you dont want to cut up your cowl (the carb is mounted on the rear). the homelite is more powerful, but for a cub, i dont think the extra ppwer is needed. the ryobi will spin a 16-8 up to a 18-8 prop.
if you need more info, go to the conversion engines section of this site. lots and lots of info

RE: Engine for Piper cub

Quote:

ORIGINAL: andrew66

i think a nice homelite 25cc or ryobi 31cc would be very nice. they are cheap to convert and dont use hardly any fuel. the 31cc ryobi is nice, if you dont want to cut up your cowl (the carb is mounted on the rear). the homelite is more powerful, but for a cub, i dont think the extra ppwer is needed. the ryobi will spin a 16-8 up to a 18-8 prop.
if you need more info, go to the conversion engines section of this site. lots and lots of info

Hey, thanks for the info! I'll go take a look at the conversion section. Thanks again.

RE: Engine for Piper cub

i 2nd that one....homelites rock!

RE: Engine for Piper cub

I've only seen one of the Evo's in use, it seemed to run fine for its owner, and he was happy with it. It looks like a glow engine with a gas carb on it. the exhaust is out the side, and I'm pretty sure Slimline or Bisson would have a Pitts style muffler for it. As far as the conversion engines go, there are a lot out there, bur most seem to have a side carb. try Carr Precision's website, they have several different brands available, and several ways to go. You can send them your engine and they will convert it for you, or they will sell you the conversion parts and you can do it yourself, or they will sell you an already converted engine. they even have a 4-stroke Honda engine available.

RE: Engine for Piper cub

I have a SIG 1/4 scale cub. I have a quadra 35 in it. The only hole I have is for the carb, and it is not that noticable.

You can pick up Quadras, or US 41's pretty cheaply on RCU.

I also used the hangar 9 cowl, as it was cheaper, and had the motor heads molded in.

I have a SIG FS 120 with a ryobi 31 in the nose, with CH ignition. For the cub, I'd still go with a quadra or similar.

Now, if the plane ws a showplane, I'd spend the money and go with the Evolution like mentioned earlier. No cowl holes is very cool. after all :)