what is the difference between an automobile engine and a marine engine?


what automotive parts can you put on a marine engine (heads, cam, etc.)?

Valves can be different, Alt. and starter are sealed, carbs are sometimes different. cam setups can be diff in H.P. aplications to prevent water reversion. Thats about it.

Most gas marine engines are automotive engines. Especially the older Mercury black motors. This was also true for the Volvo and Cobra engines. To meet Coast Guard regs, the fuel pump and carburator are specific to a marine engine. The starter, alternator and distributor will also be marine specific. For a mild engine, I assume they retain the stock cam. For the racing engines, they are changing the cam out for something with more lift and less overlap to control reversion. The newer blue Mercury racing engines are more marine engine than automotive though.

so then, i could take my 302 (188 h.p.) powered 22' sea ray, add a cam, heads, 4 barrel intake and carb and increase it's current 32 mph top speed?

drain plugs.... brass soft plugs

i was told bearing tolreences are set up looser?

Not on the black motors. I know that they use the low tension oil rings that GM uses in their cars for milage reasons. That's why the 502's are known to use some oil.