Advice on 5.7 mercruiser/vortec replacement

[lr3guyjoe]

I’ve just picked up a project with a bad motor. The story goes it started overheating and they kept driving to get back to the dock. Then it wouldn’t turn over after the shut it off. Just got the motor out and it’s full of water and it’s been sitting for about 6 months and it was brackish water so it’s pretty bad.

It’s a 5.7 2 barrel 1997 vortec style motor 880 block 4 bolt mains with a mechanical fuel pump. I’m thinking of doing a reman long block but the mechanical fuel pump seems to be an oddity and everyone is 12 plus weeks.

My other thought was to get a used truck motor and put a marine cam in it but they are all electric fuel pumps as well. Could I just install and electric fuel pump from like a 4.3 mercruiser?

The other question is going with a 2 bolt main a no go? It seems like some are 2 bolt some are 4.

Any other suggestions?

 

[jimmbo]

Mechanical pumps were for many years and are fine as long as they are USCG approved. Replacing it with an Electric pump requires that the Pump doesn't receive Power unless the Engine is Running, or being Cranked to start, again USCG Regulations. Any any Ignition System Parts have to be USCG approved
An engine with 2 Bolt Mains is Adequate for the RPMS these Engines will see running in a Marine Application. You will also have to replace all the Core Plugs with Bronze or Stainless Steel ones, a Marine Grade Water Pump will be needed. The Intake manifold on Marine Engine often have the Coolant Passages coated/veneered with copper to reduce Corrosion Problems, Head Gaskets might not be compatible with Sea/Brackish Water, and would need to be replaced with ones for a Marine Engine

 

[lr3guyjoe]

Thanks for all the info! Especially about the 2 bolt mains. So it sounds like the truck motor is a possible solution.

For the fuel pump I’d wire it like the one on my 4.3 I know there was a lug on the starter for power during crank and I think it had an oil pressure switch for engine running power. I guess my main concern was would the 2bbl carb be fine with it.

 

[achris]

... I guess my main concern was would the 2bbl carb be fine with it.

Those electric fuel pumps can keep a 750cfm 4bbl Weber supplied, so a little 2bbl Rochie isn't going to be a problem.

Chris....

 

[nola mike]

Thanks for all the info! Especially about the 2 bolt mains. So it sounds like the truck motor is a possible solution.

For the fuel pump I’d wire it like the one on my 4.3 I know there was a lug on the starter for power during crank and I think it had an oil pressure switch for engine running power. I guess my main concern was would the 2bbl carb be fine with it.

And no need to swap the cam, just plug and play

 

[lr3guyjoe]

Thanks. I’m picking up a motor from a wrecked truck today.