ORIGINAL: cappaj1
ORIGINAL: codfish
Cappa,
The cylinder is totally outside the cowl so you do not need any air exit in the bottom of the cowl.
If the cylinder was inside the cowl the rule of thumb is the air exit needs to be 2 times larger then the inlet.
Okay, so if I make the hole smaller than the one shown in my picture, but the cylinder head is still sticking out, which it will be, you're saying I don't need any cut out underneath the engine? That'd be great - a nice clean look!
Correct, bit of course you need a cutout for the muffler, so there will still be a small hole in bottom.