4.3 engine compatibility

[danny9696]

Hi all a friend of mine bought a boat with a mercruiser 4.3 that had been frozen and the block broke, we would like to know if there is a difference between an automotive long block and a marine long block, there is a price difference just not sure what the differences could be, maybe a cam and valves?

Any info would be great, thank you

Danny

 

[cr2k]

Re: 4.3 engine compatibility

A marine engine is not a smog engine so it has a little better cam.
I have been told that a 4.3 of the same type (balance shaft or no balance shaft) from a pick up is very close and should work, but not so much a car engine. You should also change the circulation pump for the marine one (what would be called a water pump in an car/truck) as well as ALL the electrical and fuel related accessories, starter, alt, carb, fuel pump etc.

 

[danny9696]

Re: 4.3 engine compatibility

Right on! thank you I found a new Chevrolet S10 4.3 with a 3 year unlimited engine for $1450, or a marine 4.3 1 year unlimited for $1950, but was not sure if the automotive engine would work,

thank you very much

Danny

 

[Gary H NC]

Re: 4.3 engine compatibility

It will need to have brass core plugs installed and have the same type rear main seals....the one piece or two piece seal...whatever the original engine has.
A truck engine will have a cam close to a marine cam.A car engine will not.
Have you checked with Rapido Marine?

As far as a warranty on the car engine,you can forget it if installed in a boat.
I doubt any warranty would be honored in that case.

Ready to bolt in marine engines...

http://www.rapidomarine.com/default.aspx?p=/engines/default.aspx

 

[zbnutcase]

Re: 4.3 engine compatibility

Luckliy not many 4.3s were used in cars, most are truck/van engines

 

[danny9696]

Re: 4.3 engine compatibility

Thank you all for your help it was very informative, one more question, what is the reason for the brass freeze plugs

Thank you all again

Danny

 

[180shabah]

Re: 4.3 engine compatibility

what is the reason for the brass freeze plugs

Steel plugs are the norm in the auto world 'cause they are cheaper, but they don't last long in a marine environment. You don't want any steel in contact with your raw water cooling. Same reason, the head gasket is different in marine engines.

 

[danny9696]

Re: 4.3 engine compatibility

Right on thank you so much, you guys have just proved my point to a buddy about the difference of the marine and automotive engines in his boat

You all are great thank you very much

Danny

 

[cr2k]

Re: 4.3 engine compatibility

Steel core plugs will rust out in a boat unless you have a closed cooling system.

I don't think there is a 2 piece rear in the 4.3 models. But thee are 2 designs one with a counter balance shaft that runs under the intake - newer vortec
And one that doesn't 88-? year model.