Car engines in boats?

[trash2cash]

I have a question about car engines installed in boats. Is the engine cooled by water, or do they have a seperate radiator. I was curious because i seen a Youtube video of a 455 V8 engine on a boat. Boy those things haul!

 

[jtexas]

Friend of mine had a boat with a chrysler 383 hemi...we plumbed the engine block water inlet to a thru-hull fitting in the floor of the boat, thinking the bournoulli effect would cause it to draw water. After it busted a piston, we installed an electric water pump, worked great. I dunno, maybe it overheated cause it got no water at idle, probably didn't need the pump at speed.

That was just a DIY/hacker kind of solution, I'm sure a professional design would work way better.

This engine was installed just aft of a bench seat (only seating in the boat), and had no cowling whatsoever. Which is a good thing, since automotive components aren't shielded to prevent throwing sparks the way marine components are, on account of the close proximity of fuel tanks to to the engine.

Through-transom exhaust above the waterline with no mufflers--you could really wind that motor up if you wanted to. If we'd got around to installing a tach before it got stolen, I could've told you how many RPMs it would make.

 

[BeerandTVOlympian]

This can be engineered to run either way. If you are in a high salt environment then you want to set it up as a closed cooling system (one that uses a heat exchanger).