will 4.3 mercruiser engine parts fit in a chevy 4.3 block

[mrdmwhite]

Long story short have a freez cracked 4.3 95 mercrusier. Can I swap all my engine parts..CAM, Pistons, Crank etc into a 4.3 chevy block?

 

[Bondo]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Long story short have a freez cracked 4.3 95 mercrusier. Can I swap all my engine parts..CAM, Pistons, Crank etc into a 4.3 chevy block?

Ayuh,.... Welcome Aboard,...


You'll be way ahead of the game to just get a Chevy 4.3 block that's already got it's own parts in it....

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

I know I can get one for 1500....But I can get a bock for 100....this mercrusier only has 1000 hours on it and im try to save cash...

 

[dubs283]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

the long block has all chevy parts in it, mercruiser buys em from GM

the external components are added by mercruiser

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Great...So I should be able to just swap everthing off this engine and put it on the chevy block...

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

If I use all the parts should I at least change out the rings, bearings and oil pump and new gasket set?

 

[ussoldier_1984]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Yes while the engine is open it deffinitly would be the right time to put new rings in it and bearings, no matter what you have to put new gaskets, You need to put new cam bearings in the engine if you dont when you swap the cam it will prematurely wear out the cam with two different old wear patterns, so take it to a machine shop and have new cam bearings pressed in.

 

[dubs283]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

thats up to you

if it were me, yes i would definitely do all that - especially the gaskets

if you are digging that deep into an engine its best to get all that stuff taken care of

 

[Bondo]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

But I can get a bock for 100....

Ayuh,... Is this $100. block got clean virgin bores, that Matches yer pistons,..??

 

[Don S]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

You also need to measure bores, pistons, crank and rod bearings etc. to make sure everything is within spec of what is should be.
Wouldn't want to put new standard bearings in only to find the crank undersized by .010 or the new engine has been bored out .010.
If everything is in spec, the cylinders should be honed and new cross hatch put in, and new rings.
After a 1000 hours, might want to have the heads checked out to.
As far as new gaskets, well that's a DUH. You NEVER reuse gaskets. They are one time use only.
After all that, you now know the internals are like new and ready for a few thousand hours. .................... If you keep the water out of it.

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Thanks for all the replys....I knew not to use old gaskets just threw that in on the list...
I never thought about new cam bearings....I was going to double check and measure everthing to make sure no work was dont on the block and check to make sure nothing was bored out or crank bearings changed..I was going take it to a machine shop and have the block checked and measured too. I will get those new cam bearings pressed in. I was thinking about a new oil pump while im in...I just knew if I did this it would be cheaper than 1550 bucks for a long block.

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Second question will new cam bearings wear on my used cam?

 

[Jmunk]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

I have put used cams in blocks with fresh cam bearings numerous times, never an issue make sure there is no scoring any imperfections on the cam.

 

[dwayne80]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Make sure u check that block to see if it's a manual or electric fuel pump, I did the swap and forgot to check. I did complete swap, used all bearings and cam all I bought was gaskets and silicone, of course inspect parts for wear.

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Ok here is some updated info...This freeze cracked engine only has 197 hours on it not 1000. Can anyone help on matching my engine serial number to a chevy block I can look for. The engine is a 95 MCM 4.3 LX Alpah One Serial number 0F585994. Again I just want to swap all my components into a compatable Chevy 4.3 block. I need to have a starting point on what block to look for. I am hoping this block at the junk yard is compatable. I will have to get the numbers off it.

 

[mrdmwhite]

Help matching a 4.3 chevy block

Help matching a 4.3 chevy block

Messed up

 

[mrdmwhite]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

Ignore this reply messed up on starting a new thread

 

[Don S]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

I just merged both threads into one. Do not post different threads on the same subject, it just confuses things.

 

[Bondo]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

I need to have a starting point on what block to look for.

Ayuh,... On the motors aft flange, behind the head, near the top, probably slightly portside is the block's Casting #s...

Match it with the same, 'n it's as good as it gets...

It'll probably match a block found in a 93/ 95 pickup truck...

 

[btcox123]

Re: will 4.3 mercruiser engine parts fit in a chevy 4.3 block

I just finished a block swap on a 4.3, this is possible but you may have many challenges ahead of you, and the overall cost can be more than expected.

This 1988 OMC had a large crack in the lifter valley, but the crank, rods and pistons were in great condition as was the cam, lifters, etc. I used a donor 1998 truck block.

Here are some key points to compare when looking to swap blocks;

1. mechanical fuel pump Boss

2. balance shaft vs. non balance shaft

3. 6 or 10 bolt timing cover

4. steel oil pan, or aluminum oil pan

5. a Tonwanda built engine or a Romulus built engine

6. a 5/8" oil pump pickup tube or a 3/4"

That's just a few key points, but their are wide range of differences between automotive, and marine, or year model to year model, or manufacturing origin.