Auto engine vs. Marine 1996 4.3 Mercruiser

[Bansheex13]

My 1996 4.3 is in need of a rebuild,I know the cam is different and the gaskets are different but can I use auto pistons,rods,crank bearings etc? What is different from a Marine and Auto motor? I want to rebuild my shortblock.

 

[Reel Poor]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

It may be possible that you could use a truck short block for your application with some part changes. If you'll use the forum search option above you will find days of reading on this question.

 

[180shabah]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

Short, short version. The rotating assy is the same. Cam, head gaskets and core plugs are different.

 

[Bansheex13]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

I did search but found little ( I'm not good at searching forums).That pretty much answers the question though.I just want to use a short block from a Blazer or something close.Is the compression ratio the same from the car to boat?Pistons?

 

[Don S]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

Do a search, this subject only comes up once a week.

 

[180shabah]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

Then entire rotating assy is the same. Crank, rods, pistons, bearings, the whole works. If your donor engine is from a blazer(or other truck variant) then the cam will also be ok (assuming it is the stock one) to use. There is nothing magic that makes it a marine engine. Just do not use any of the electrical, fuel, or cooling components from the truck. Those MUST be marine rated.

 

[brunolund]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

i did the same thing in my boat. i'm using auto head gaskets though, but my engine is fresh water only. it works great. i used a 90 4.3 from a jimmy, and my boat is a 96. no problems at all.

 

[180shabah]

Re: Auto engine vs. Marine 1996 4.3 Mercruiser

i did the same thing in my boat. i'm using auto head gaskets though, but my engine is fresh water only. it works great. i used a 90 4.3 from a jimmy, and my boat is a 96. no problems at all.

Auto head gaskets can be used without a problem as long as they are not copper or steel. There are many options straight off the shelf at napa, etc. that don't say marine but are still acceptable.