Parts interchange between chevy smallblock family and mercruiser 140 3.0 liter

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Chevyls6

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Does anyone have an idea what parts can be used from a smallblock engine in a mercruiser 140? I'm getting ready to rebuild my shortblock and would like to save money since sbc parts are usually the cheapest of any engine.

The block is going to the machine shop to be crack checked this week and from there either bored or sleeved. I am definitely gonna need pistons and rings plus new valvetrain and bearings. I've got 2 cores to choose from a 1974 and a 1987. Are there any benefits to one vs the other? Theyre both 2 piece seal blocks.
 
alldodge

alldodge

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Don't use either IMO.
Get a truck motor from a junk yard, 1995 or newer and change core plugs. You will need marine Dist, Carb, Starter and Alt
 
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Chevyls6

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Im sorry if my question was confusing. I am actually rebuilding a 3.0 shortblock to go back in place of the original 3.0. A 5.7 swap is beyond the scope of this project.

I'm mostly interested in knowing if things like piston rings, lifters, rod bolts, etc will swap between a smallblock and the merc 3.0 as i've heard it said that the two engines share some parts.
 
alldodge

alldodge

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Chevyls6 said:
Im sorry if my question was confusing. I am actually rebuilding a 3.0 shortblock to go back in place of the original 3.0. A 5.7 swap is beyond the scope of this project.

I'm mostly interested in knowing if things like piston rings, lifters, rod bolts, etc will swap between a smallblock and the merc 3.0 as i've heard it said that the two engines share some parts.
Click to expand...

No idea, I'm out
 
Scott Danforth

Scott Danforth

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Your 74 and 87 blocks share nothing with an SBC other than the flywheel housing pattern

Your 3 liter motors are stroked and bored variants if the 2.5 liter / 153 cubic inch motors which was the 4 cylinder variant of the 230 cubic inch 6 cylinder (1962 to 1980)

Not until the 1991 and later motors do you get a 4.0" bore which shares the same bore with the SBC 350

The 3.0s you have were built in the mexico industrial engine plant, and shares vary little with anything
 
Scott Danforth

Scott Danforth

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1960 Starflite said:
Just Edification for you youngsters 😊
Click to expand...

However because of the 3.6" long stroke of the 181 4 banger compared to the 3.25" stroke of the 327 or the 3" bore of the 302, the piston compression heights are different
 
Bondo

Bondo

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Scott Danforth said:
However because of the 3.6" long stroke of the 181 4 banger compared to the 3.25" stroke of the 327 or the 3" bore of the 302, the piston compression heights are different
Click to expand...
Ayuh,..... 'n then there was the 3.5" stroke, 'n the 350 was born,.......
 
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Chevyls6

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good info guys

I did a little checking and it doesn't look like 230 I6 parts are gonna work either.

Anyone ever reuse rod bolts on these? paying $80 for a factory set from mercury isn't ideal.
 
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