I guess HP isn't really the issue so much as speed and torque. Torque is a very good thing but you don't want so much that you twist the drive shaft off of your saw. And the thing about speed is when you start getting into larger engines, definitely when your up to the 25 hp and up range, is that their going to put out their peak power at about 3000 if not more rpm's. What you want is a fairly slow running ( same range as your bandsaw runs now) saw so that it doesn't look like you cut your wood up with a torch, that has lots of power behind it so it doesn't get bogged down.
Remember that HP is a rating of energy put out in a certain time frame. So some engines have high horsepoewer because they run at high speed, but are pretty ****ty on torque. When you look at engines, try and find the torque rating, or look for the engine that puts out its peak power at the lowest rpms. It'll also save gas, and make it run cooler.
You may want to come up with some kind of clutch to put on it to, or get an engine thats set up to idle with a flywheel so that you can pull the throttle back between cuts and have the blade stop without shutting the motor off.
In the end you should have a hell of a bandsaw.
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It'll feel better when it stops hurting.
. it needs to have a single drive shaft. what would the dimensions be?
