Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc 4.3L

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Noltz

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

Are you asking if a Chev 5.0 V8 harmonic balancer will fit a 4.3 V6? The answer is yes, BUT. There's 3 different size balancers for the old 305; 6 1/4", 6 3/4" and 8". I used to get asked this question every time I ordered a dang belt for these engines in the C and K-series pickup trucks. Just checking over on summitdirect I found a few balancers that list both engines in their descriptions. I am NOT a marine mechanic and I don't know if the belt arrangement is the same from automotive to marine, but if they are you may find ordering a balancer straight for the V6 to be your best bet.
 
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Ming15237

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

Hermonic balances are engine specific, they are very different from v6 engines to v8, their objective is to counteract the harmonics of cylinder firing operations, which are different from v6 to v8. Damage to a crankshaft can result by using the incorrect one.
 
achris

achris

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

ok... Here's what I found. This only applies to non-vortec engines.

The front cover seal for the V6 and V8s are the same, means the hub outer diameters match. The timing tab used on both engines is the same, meaning the balancer outer diameters are the same. The cam timing sprockets are the same, so the hub inside diameters are the same. Even the pulleys on some engines (V6/V8) are the same. That means a marine V8 balancer will fit on a V6 engine... BUT... as the V6 and V8 are both 90? vees, making the V8 a balanced engine, and the V6 an unbalanced engine, the weighting of the pulleys are very likely to be quite different....

Would I put a V8 balancer on a V6 engine? Most definitely NOT!!!!

Chris......
 
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Fun Times

Fun Times

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

Agreeing with no! The Mercruiser part numbers do not cross over between V6 & V8 in the 1988 year range. Your OEM part number would be 11990 while the SB-V8 part number for 1988 would be 75420.
 
Bondo

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

Ayuh,.... I agree, while it might bolt on, the motor will vibrate to beat 'ell,....

The 4.3l is a uniquely balanced motor,...
'n it's unique balance changed several times durin' it's production run,...
Both the harmonic balancer, 'n the flywheel are not only Motor specific, but Vintage specific as well,...
 
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Noltz

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

We're getting a little off topic, but can someone tell me how the V6 is unbalanced more than a V8, or are we simply talking able power stroke overlaps? It's my understanding they changed the crankshaft to 30? offsets and effectively deleted #2 and #4 cylinder? I know in about mid '95 the blocks were changed to add a balance shaft simply because 90? engines don't idle smoothly.. but I'm genuinely curious about the balance.

To the OP, get a V6 dampener. Until an engineer says they're interchangable, it's not worth risking an engine over $100.
 
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1988Larson

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Would anyone happen to know the part# for the harmonic balancer on a 1988 4.3L merc??

Would anyone happen to know the part# for the harmonic balancer on a 1988 4.3L merc??

If anyone would happen to know it would help a lot!!!
 
ktbarrentine

ktbarrentine

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Re: Would anyone happen to know the part# for the harmonic balancer on a 1988 4.3L me

Re: Would anyone happen to know the part# for the harmonic balancer on a 1988 4.3L me

11990 (as seen on ebay and dealtagger) Looks like its obsolete on the normal parts sites. (guess he didnt want to get the info posted in his other thread).
Put this into ebay: "HARMONIC BALANCER CRANKSHAFT MERCRUISER 4.3 LTR 175 185 205 4.3". Looks like your best bet so far...
 
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Fun Times

Fun Times

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achris

achris

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Re: Can I get a harmonic balancer of an 8 Chevy engine that will work for my 88 merc

The 90? V6 is unbalanced because in order to have an even firing crank, the journals need to be offset, so the rods aren't directly opposite each other... The reason your V6 got a balance shaft was nothing to do with idle. It was to dampen a harmonic at around 1800 rpm.... Before the balance shaft, they tried 'fluid mounts'....

A properly balanced V6 would be 60?, like the big Merc outboards.

Chris....
 
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