Yep, you sure are right Buck. I started out with a lowly 16cc Echo on a Big Stik. I loved it and never looked back. Now I have 5 airplanes flying conversion engines, my friends and family have engines flying converted by me, I've sold some, and I must have 20 good engines waiting to be converted!! (Nope guys, it's my prized collection and sorry, but I don't want to sell any.)

Your formula is correct, but I use "(bore x bore) x stroke x .7854". If you measured in inches, this will give you cubic inches. To get cc, divide by .061. Same result, different method.

AV8TOR