Tech Tip
If you're planning on trying to improve the performance of your boat this spring or if you have a customer just rebuilding his engine, check these few things first. When choosing a cam for a marine engine, the first thing you need to know is the type of exhaust that is being used.. There are several different types of marine exhaust systems which determine how big a camshaft you can use. If you have exhaust logs or underwater exhaust, you must use a cam with no overlap at .050" lift because of the back pressure created by the water in the exhaust system. If you have a through hull or above water exhaust system, you can choose a cam with up to 4 - 6 degrees of overlap at .050" lift. If you have double wall or water jacketed pipes that mix the water and exhaust at the end of the tailpipe, you can usually use any cam that would best match the compression and RPM that you want to prop the boat to at maximum speed. So make sure before you or your customer choose a camshaft, that you know what type of exhaust is in the boat. You don't want to end up with water in your engine.
