Which kit is your P-39
It's a Global Quality Kit. I have a build thread available ( [link=http://www.rcuniverse.com/forum/m_6334567/tm.htm]here[/link] ).
Third, looking at the position of the engine at the spinner plate it looks like the engine is not centered in the cowl.
I just placed the engine on the mount to take a picture. It's not screwed down to the mount, but once it is screwed in place, it is centered.
if there is an offset angle (right thrust) built into the firewall
The instructions didn't mention anything about the offset angle and I didn't see one once I installed the firewall. The engine is basically centered with no offset. The problem with reversing the firewall installation is that it caused the engine to be about 1/4 inch off center. This picture shows it a little better.
The engine should be on the left side of the mounts when looking from the front. I had to flip the engine to the other side to center it.
lot of fuel residue on the plane that will make for a messy clean-up
Yeah, that's not going to be fun. I think I may purchase one of those hoses to extend the muffler and route the residue down.
It's a big fix, but not really too bad.
Unfortunately, there is no turning back now. I weighed all the factors and decided it simply wasn't worth tearing everything apart.
I'm mainly worried that having the muffler on top will cause the residue to leak back into the cylinder. Or that the fact that the needle valve in on the bottom, fuel would have a problem reaching the carb. Is this a possibility?