Engine help

[bstrawn1121]

I have a 94 5.0 L V8 mercury in my boat. Last winter, it was not winterized properly (I am an idiot!) and its block was cracked. My question is will a crate engine (purchased at an auto parts store) work? I mean is the block altered when Mercury mairinerized the engine? Will all of the intakes and manifolds match up on a crate engine?

If so, what size of engine is it - a 305? Thanks for your help!

 

[imported_TheMan]

Re: Engine help

There are a lot of Chevy V8 experts around here, so they will give you some more detailed information.

Just to get the ball rolling though, yes, you can buy a crate motor and it will work as long as you have the same model engine. Yes, a 5.0L is a 305 engine. The marinization process usually refers to the ignition components, although the camshaft is probably different as well due to the operation. They did not alter the block as far as I know, with the exception of installing brass freeze plugs.

You will need to use all of the marinized components from your scrapped engine.. If you get a same model engine (year range) and use all of the same parts you should be good to go.

You should make sure your exhaust manifolds are not damaged as well.

Sorry to hear about your boat and welcome to iBoats.

 

[bstrawn1121]

Re: Engine help

Thanks for your reply. Looking forward to hearing the input from the V8 guys.

 

[MikDee]

Re: Engine help

Why not just get a 350 V8? It's all the same outside as the 305, only the internals are bigger. Anyway, I think the only differences between these auto blocks, and marine is the head gaskets, (possibly stainless, on marine) & brass freeze out plugs, But you must use All your marine external parts, for USCG safety reasons, and preferably the marine water pump (though not as important as the rest). They should all bolt on if you get a matching model year as yours (I think?), and be sure to check your marine exhaust manifolds good! or replace them with new ones to be on the safe side. One more thing to assess if good, is the engine coupler, because you can't get at it to change once the engines in! Good Luck, Mike

 

[bstrawn1121]

Re: Engine help

So if I get a long block crate 350 or 305 I am going to have to remove the heads to replace the head gaskets?

 

[MikDee]

Re: Engine help

So if I get a long block crate 350 or 305 I am going to have to remove the heads to replace the head gaskets?

Saltwater use, Yes, definitely!,,, freshwater, not necessarily. I'd chance it myself, but that's up to you.

 

[hard-3]

Re: Engine help

be sure to check if all of the mounting holes are tapped . some marine accessories mount to the block where there were not intended for on an automotive application. be sure to check the specs for the replacement to get a compatible camshaft profile, and compression ratio. some of the middle 80's auto engines were designed to run an airpump exhaust manifold and had very low compression pistons because of the emissions standards for highway use. You would not want to get a low powered dog engine as a replacement for a high hp marine engine.

 

[bstrawn1121]

Re: Engine help

she does not go in saltwater, so I guess I will not remove the heads. As for choosing the crate engine, is there a number on the block that I need to have when placing the order? I apologize for my lack of understanding

 

[John_S]

Re: Engine help

If you are talking GM crate engines, look up the part numbers. When I researched their iron vortec crate, it had SS/graphite head gaskets. Good to go, even if in the salt.