4.3 Mercruiser and Alpha One 1987

[xjmav]

Just bought a new boat, bad motor bad interrior, full restoration project ahead of me.

Its a 1987 Rinker V180 Paired with a 4.3L Mercruiser and an alpha one outdrive

Pulled the lower unit today and all looks okay,

Pulled the motor and... well not so good.

Cracked exhaust manifold water jackets as well as blown freeze plugs.

Water in oil as well. So as far as I can figure, Im shopping for a new block.

My questions are as follow;

My family has been in the fabrication industry for years and my father and uncle believe they can weld up the cracks in the exhaust manifold water jackets, haas anyone had luck with welding them? Should it be ok?

What do I need to look for in the lower unit while it is out. What parts to replace what to check etc.

What production years of the GM 4.3 should I look for to use as a donor block.

Anything else I should know while undertaking the new project.

Thank you for your time and knowledge!!

 

[tschmidty]

Re: 4.3 Mercruiser and Alpha One 1987

You might be able to weld them, but if you are putting in a new block why take a chance on old manifolds? There is not a lot of pressure so your repair would probably work but still doesn't sound like a great idea.

Not exactly sure which years but I think 87 to 93, but others can speak more authoritatively. Of course you need to marinize it, brass plugs, marine/truck cam. I'd probably look for one already built. Like from here.

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

 

[Don S]

Re: 4.3 Mercruiser and Alpha One 1987

You might be able to weld the outside cracks, but that doesn't fix the internal cracks that you can't get to.

 

[Bondo]

Re: 4.3 Mercruiser and Alpha One 1987

My family has been in the fabrication industry for years and my father and uncle believe they can weld up the cracks in the exhaust manifold water jackets, haas anyone had luck with welding them? Should it be ok?

Ayuh,... They could weld on 'em for a Week, 'n not be sucessful....

Find a 4.3l pickup truck motor from 86 to 93...
It'll make a Good base motor...

Replace the manifolds with New 1s...

 

[xjmav]

Re: 4.3 Mercruiser and Alpha One 1987

Ok, I will check into new ones.. A little pricey. Does anyone know of a good aftermarket or online place to purchase good quality at a decent price?

Found a block hopefully. It has been boored .030 over and is supposedly a good block from the late 80s non balancer and has sat on an engine stand since machined. The guy is asking $100 including the stand. Everything I have reasearched says the 4.3 has a 4.00 in bore is that correct? So in theory I would just need a pair of dial calipers to check bore size?

With that being said, does anyone have any links pertaining to mercruiser rebuild kits, or can I use a standard 4.3 kit (pistons needed with new block) and swap out manifold and head gaskets as well as freeze plugs?

Thank you for all of your quick replies. I really think I am going to enjoy this forum site, seems to be alot of knowledge here.

 

[Bondo]

Re: 4.3 Mercruiser and Alpha One 1987

With that being said, does anyone have any links pertaining to mercruiser rebuild kits, or can I use a standard 4.3 kit (pistons needed with new block) and swap out manifold and head gaskets as well as freeze plugs?

Ayuh,... Use either Mercruiser, or marine rated Fel-pro gaskets...
For Pistons, Hyper's are plenty good enough, 'n better than cast....
Coreplugs gotta be Brass...

 

[xjmav]

Re: 4.3 Mercruiser and Alpha One 1987

What do i need to look at/ service while the outdrive is out?