95 MerCruiser 4.3 cracked block

[Boatbuyingloser]

Hello, this is my first post and first time trying to restore a boat. I've had a problem when the motor is running where it wouldn't get above 4k rpms and had a rough idle. When trying to diagnose we have zero compression on one of the cylinders and when we looked closer, the block had a crack in it. I plan to rebuild it but as a marine motor is different from an automotive one, Im not entirely sure how to go about it. I was thinking I could tear the motor down, get a new block and build it back up from there. I was wondering if anybody had better ideas or solutions. Also I'm not sure if automotive 4.3 blocks are the same as mercruiser block, I would assume so but I need some input. I would rather buy a new motor, but the only ones I can find are over $2,000. The boat is a 95' Celebrity open bow 18'

 

[Rick Stephens]

Generally speaking it costs about the same to recondition rods and crank as it does to purchase a brand new Scat assembly. And seeing as how you need a block as well, might be even more responsible to find a used truck pull and have it gone through or do so yourself. Was mine, I would seriously consider rebuilding a pull and then balance the cost to purchasing a rebuilt motor that comes with a warranty.

 

[Scott06]

If you get w truck 4.3 from a wrecking yard and rebuild it its your best bet. Very little diff between a truck and marine engine- marine head gaskets and brass freeze plugs thats it. Cam is slightly different but general consensus is truck cam will work fine. Strip it to long block and move your marine accessories, intak, carb, ignition over

 

[kvkon]

If you get w truck 4.3 from a wrecking yard and rebuild it its your best bet. Very little diff between a truck and marine engine- marine head gaskets and brass freeze plugs thats it. Cam is slightly different but general consensus is truck cam will work fine. Strip it to long block and move your marine accessories, intak, carb, ignition over

Exactly what I just did. Used an 090M casting block out of an upside down 03 Blazer. It had 113 casting heads which were also correct. I reused the entire rotating assembly in order to maintain balance. A guy who sounded smart told me the Mercruiser cam is a little hotter than the Chevy cam so I reused mine. Only difference was the dipstick tube location. I had to tap the hole and run a pipe plug in it. Every thing in I was still way less money than a long block full of mystery parts.

 

[Scott Danforth]

Block and heads dont know if they are in a truck or boat