Marine vs. Automotive crate motors

[techspecial]

I've read where some of you have recommended automotive replacement motors. Is there any significant difference between marine and automotive.
I don't mean the obvious manifolds and all the other auxiliary equipment.
I just mean the block/heads and all the internals. When the time comes I'd like to replace my 350/260 small block with a 383 stroker in my Minx.

[joseph m. hahnl]

I don't Know this for fact,But some one told me the water jackets are different. He said they decrease the jackets and thicken the cylinder sleaves.
as most marine engines are raw water cooled. It helps from getting thermol shock in the cast iron. To me the Best way to go is to stroke the 260. if you make it a winter project. you can buy a lot of high performance stuff for what you might buy a motor out right for. Not to mention the sence of pride you'll get doing it all your self.

Oh and lets not forget the admiration of you fellow Donzi pals.


joe

[Rootsy]

marine engines differ in a few areas. first is the use of brass freeze plugs, though most engines these days come with them. the other main area of modification is piston to cylinder fit and the gap on the top compression ring. Both of these are due to increased expansion due to heavier and increased duration loads imposed on marine motors... other than that they use the same parts as a car... marine engines generally have camshafts that are better suited to boating and loads.. lower peak RPM for hp and a flatter torque curve.. but anymore folks like GM use a general cam in many engines..

BUT numerous auto engines have been used in place of marine engines without issue... so the above statement may be a moot point and have no bearing on anything what so ever... unless i reckon you are getting into big hp super high load extended wot operation with a motor... but for the average boat... i reckon just swapping in an automotive engine would work just fine

[Speed-Racer]

Also high volume oil pumps, and marine grade gaskets...