J-3 boot cowl and engine cowl on a PA-18

[j3flyer]

If I were building an experimental PA-18, would stock J-3 cowling fit, especially the boot cowl ? I really like the look of the J-3. To build an experimental Cub, using a standard width PA-18 fuselage, would the J-3 cowlings and windshield work? Engine choice would be C-85, or O-200.

 

[Cub junkie]

Yes it would fit. PA11 w/s looks better.

 

[JimC]

It can be made to work. Shape of boot cowl, engine height, and engine droop angle are substantially different between the 3 and 11 or 18. Fore-aft location of the firewall is about 3/8" different

I would use a non electric 9.5 compression O-200 timed at 28° with an MA3-SPA 10-4115 carb and a Mac 7440 prop as a good compromise between climb and cruise. Cruise would be about 95 mph at 2550 rpm. About 80-81 mph at 2350 rpm. Top speed would be about 115-118 mph. Do not use intercylinder baffles with the open cowl. A-65 exhaust will work with the headers extended about 5/8 inch. A-65 engine mount will also work.

With about 5-10 minutes work on the rudder hinges, the J3 rudder can be used in lieu of the 18 rudder.

 

[WhiskeyMike]

. Do not use intercylinder baffles with the open cowl.

Are you certain about this?

 

[JimC]

Yes.
You do use them on the PA-11, but not the J-3.

 

[barijr]

I agree with Wayne. JLB Jr.

 

[JimC]

I have both. I actually prefer the 'feel' of the J3.