Simple question...

[kramgam]

Can i use any motor to make my boat an inboard?
Thanks

[Ike]

No. There are significant differences between automotive engines (I am assuming you are considering gasoline engines) and marine engines They are based on the same blocks and many of the components are the same, but the differences are critical.
Here's a link to Marine Engines 101: http://blog.360.yahoo.com/blog-7gAuM...jWwp_TA--?cq=1 See the January 8 and January 9 entries.

[Jango]

Other than the marine fuel system, starter and charging system Marine Engines (Long Blocks) are no different than "Truck" Engines. Camshafts are nearly the same. (exactly the same on my Ford Mercruiser)
Basic differences are water pumps (Brass or S.S. Impellers). Gaskets exposed to water should have Stainless cores. Water cooled Exhaust manifolds and an additional raw water pump are required. Starters and alternators should be sealed to prevent sparks from contacting fuel. Carburators must be marine (venting to inside of carb rather than athmospere).
The basic Engines are the same - Trucks are built to withstand higher RPM,s under load.