The proper way to modify an engine cheaply

[Cam]

Well i mean its not like its a super saloon or pushing several hundred horsepower, the trick works well for most small 4 stroke engines and i would support saying that it actually is a one size fits all when your only working with small 4 stroke engines - not for 2 strokes of course thats a whole different bag of cats.

 

[Kaptain Krunch]

Increasing compression is great for OHV engines, however if your running a flat head, flow is more important. I would say no more than .030" off the head if its a flathead. Also, high octane gas is a myth for these little engines, unless your doing some serious compression mods. If the only thing you've done is shave the head a little, or get a thinner head gasket, dont bother.