frets, I opened up the holes in the upper cowl behind the spinner just a little more. Flew yesterday. Three flights. No engine problems. I can't get over how well this plane flys compaired to other warbirds. With that in mind I'm thinking of maybe doing a KI 100. Get another ARF KI 61, Cut off the engine box, move the firewall back and use a radial cowling. Use a DLE 20 engine. I have another set of Spring Air retracts and servos from another plane I plan to strip and decommission. I'm thinking of using the cowling for the ESM KI 84, which looks very close to the one used on the KI 100.
http://www.troybuiltmodels.com/items/ESMKI84-72FCL.html
I don't have the dimentions so not sure it would work. I did this before, changing a P-40 to a P-36. Made a nice plane.