Parts that interchange from 86 4.3 MerCruiser to 01

[brodyalbergotti]

Hello, I hate to make a new topic when its very possible this is already covered somewhere. I can not find it which I am sure I sound like a broken record but try to have some patience with me.

I recently purchased a 2001 4.3 MerCruiser long block with 4bbl carb and correct intake manifold. I have bought a few things that I know I can not use off the old motor but I would like to know a COMPLETE list of everything I will have to buy that wont work from the old motor. The old motor is a 1986 4.3 Mercruiser that was mated to a Alpha 1 gen 1 which I will not be changing.

 

[Scott Danforth]

you are looking at a gen 2 V6 (1986-1988) non-balance shaft, flat tappet motor with a 153 toothed flywheel and a gen 6 v6 (2000-2003) balance shaft, roller motor with a larger 168 toothed flywheel.. they share the displacement and bore size

I hope you got a complete 2001 bobtail and not just the longblock. your life will be so much easier with the accessory drive from a 1996 and later 4.3

you need to buy a 153 toothed flywheel for your 2001 motor to fit within the 1986 flywheel housing and coupler to mate your motor to that drive.

you need new mounts and the proper accessory drive.

 

[Rick Stephens]

I don't think there is such a thing as a 'list'. Each time is trial and error, and the search for compromises. You will be rewiring to add a correct and safe electric fuel pump - oil pressure switch, relay, priming wire from starter. You will also be plumbing said pump, making or buying mounts and fittings. Accessory drive, mentioned by Scott is always fun. Later model motors all switched to serp belts. I'm not sure it would matter whether you use the old squish motor mounts or have to purchase hard mounts - they are the same height. Never had the conversation on whether squish mounts are bad on a balance shaft motor.. And as Scott also mentioned, flywheel.

 

[brodyalbergotti]

The gentlemen I bought it from sold me what he said is the correct flywheel to work for my application i do not know how to check aside from counting teeth. He is a small marine engine guy that builds engines out of Florida and I can not get him to return calls since the engine was shipped in weeks ago. So here I am hoping to get as much help as you guys are willing to share. I did not get a bobtail engine. It is literally the long block with 4bbl intake man, valve covers, 4bbl carb, and supposedly the correct fly wheel. He said the coupler I have would bolt up and work with the new flywheel he sent. I have since ordered the fuel pump kit with bracket and 4bbl gas lines and bracket for fuel filter. Also need to order oil pressure switch and relay as I understand from research.

1- My complete old cooling system will all bolt up and work fine manifolds and risers included?

2- My old thunderbolt ignition and distributor should all work fine?

3- My old starter will work fine?

4- My pulleys, power steering, alternator, and water pump will all bolt up the same?

5- Got a 4bbl throttle cable bracket b/c old motor was 2bbl. Shifting assembly bolts to riser so I do not see a problem there.

Lots of my parts from old engine are next to new. I hate to buy anything I do not need.

 

[brodyalbergotti]

Thanks guys!

So is new mounts for sure necessary. I will buy them if its best but if you think old ones are okay I like saving money but not if it will hurt me in the long run.

I apologize but I do not know what a accessory drive drive is, could someone expand a tad. I tried to research it but did not get a great answer.

So does serpentine belt mean different pulleys?

 

[Bondo]

The gentlemen I bought it from sold me what he said is the correct flywheel to work for my application i do not know how to check aside from counting teeth. He is a small marine engine guy that builds engines out of Florida and I can not get him to return calls since the engine was shipped in weeks ago. So here I am hoping to get as much help as you guys are willing to share. I did not get a bobtail engine. It is literally the long block with 4bbl intake man, valve covers, 4bbl carb, and supposedly the correct fly wheel. He said the coupler I have would bolt up and work with the new flywheel he sent. I have since ordered the fuel pump kit with bracket and 4bbl gas lines and bracket for fuel filter. Also need to order oil pressure switch and relay as I understand from research.

1- My complete old cooling system will all bolt up and work fine manifolds and risers included?

2- My old thunderbolt ignition and distributor should all work fine?

3- My old starter will work fine?

4- My pulleys, power steering, alternator, and water pump will all bolt up the same?

5- Got a 4bbl throttle cable bracket b/c old motor was 2bbl. Shifting assembly bolts to riser so I do not see a problem there.

Lots of my parts from old engine are next to new. I hate to buy anything I do not need.

Ayuh,...... Welcome Aboard,...... #1 should work,.... #2 should work,...... #3 the starter has to match the flywheel diameter, 'n available bolt holes in the block,..... #4 should work, but won't with a serp-belt,.... #5 should be fine,....

I too, can't answer the motor mount question, as I've never run into the soft mounts, but I Think they should allow alignment, 'n work,.....

 

[Scott Danforth]

The gentlemen I bought it from sold me what he said is the correct flywheel to work for my application i do not know how to check aside from counting teeth. He is a small marine engine guy that builds engines out of Florida and I can not get him to return calls since the engine was shipped in weeks ago. So here I am hoping to get as much help as you guys are willing to share. I did not get a bobtail engine. It is literally the long block with 4bbl intake man, valve covers, 4bbl carb, and supposedly the correct fly wheel. He said the coupler I have would bolt up and work with the new flywheel he sent. I have since ordered the fuel pump kit with bracket and 4bbl gas lines and bracket for fuel filter. Also need to order oil pressure switch and relay as I understand from research.

1- My complete old cooling system will all bolt up and work fine manifolds and risers included?

2- My old thunderbolt ignition and distributor should all work fine?

3- My old starter will work fine?

4- My pulleys, power steering, alternator, and water pump will all bolt up the same?

5- Got a 4bbl throttle cable bracket b/c old motor was 2bbl. Shifting assembly bolts to riser so I do not see a problem there.

Lots of my parts from old engine are next to new. I hate to buy anything I do not need.

first, it will be a nightmare getting the old accessory drive to work on the new motor. the damper is not only a different diameter, its a different offset. if you have a hot-rodding, part swapping SBC knowledge background, you can make it work. you need to buy a new water pump, as the old water pump will not fit a balance shaft motor because on a balance shaft motor, the front cover is way different.

second, verify the flywheel. you can measure. but you need to use your existing flywheel housing. the 168 tooth flywheel will not work in the 153 tooth flywheel housing. and there is no cheap way to make a non-balance shaft flywheel fit a balance shaft motor and be right (the balance is completely different and a $79 flywheel is $300 cheaper than having your old flywheel modified)

buy a new starter, your old starter is 35# of direct drive madness, a PMGR starter is 12# of bliss

you will need a relay and an oil pressure switch to wire up a marine certified fuel pump on your 2001 motor

you should (recommended) use the solid mounts vs the gummi bear squishy mounts. will they work, yes. is it right, no.

you could have made up the fuel pump bracket (comes with the carter fuel pump), lines (they are 3/8 brake lines) and other components.

 

[nola mike]

Aside from the flywheel Scott Danforth , anything that he's doing that I haven't already done? Sounds like getting the larger flywheel and then finding a housing would work.

 

[Scott Danforth]

Aside from the flywheel Scott Danforth , anything that he's doing that I haven't already done? Sounds like getting the larger flywheel and then finding a housing would work.

the '01 has the larger flywheel, his drive and flywheel housing uses the smaller flywheel.

for the OP to use his current flywheel housing, he needs the small diameter flywheel.

you can attest to the trials and tribulations of swapping accessory drives on different vintage 4.3's

 

[Rick Stephens]

'Accessory drive' = all the stuff hanging on the front of your motor. Water pump, alternator, power steering, any idlers, fresh water pumps on some models, and last but not least, the harmonic balancer and its pulley.

 

[nola mike]

the '01 has the larger flywheel, his drive and flywheel housing uses the smaller flywheel.

for the OP to use his current flywheel housing, he needs the small diameter flywheel.

you can attest to the trials and tribulations of swapping accessory drives on different vintage 4.3's

I certainly can. The larger flywheel housing is available on eBay for $50-100. So pita, but doable.

 

[brodyalbergotti]

Thanks! You guys are awesome! I should have the install completed in a couple weeks contingent on shipping speeds.

 

[brodyalbergotti]

Just now picking this same project back up. My damper or harmonic balancer off the old 86 I realize won’t fit the 01 reading what Scott said and I kinda verified that. But I can’t seem to find any info on ordering the correct one. The ones I see for sale don’t specify too much other than part numbers.

 

[mr2nr151]

I'm doing a swap from a 93 4.3LX to a Longblock ATK Crate DMW4 4.3 I used a truck 2011 Harmonic Dampiner and trimmed the lip to keep the V belt setup. But you have to measure it. I bought a new Seira water pump from Oriellys and using the composite timing and valve covers. I used an edelbrock intake and that has kinda sucked because it moved the carb forward a little and the thermo to the pass side so I had to modify the hoses. I'm fighting the dipstick now because the larger valve covers sit right up against the manifolds and won't let the tube fit between them.

 

[nola mike]

Just now picking this same project back up. My damper or harmonic balancer off the old 86 I realize won’t fit the 01 reading what Scott said and I kinda verified that. But I can’t seem to find any info on ordering the correct one. The ones I see for sale don’t specify too much other than part numbers.

It will fit. You may need to pull the timing chain cover and remove the crankshaft position sensor reluctor under there (but you may not--i wasn't able to confirm if that was necessary).

 

[mr2nr151]

It will fit. You may need to pull the timing chain cover and remove the crankshaft position sensor reluctor under there (but you may not--i wasn't able to confirm if that was necessary).

Mine wouldn't with the composite timing cover. There was three covers used from 93 till 2010 steel, magnesium, and composite. The composite is so thick that the balancer sit maybe a 1/8 engaged before it hit.

 

[brodyalbergotti]

Okay I can’t remember if mine is composite or not. I will investigate that and the sensor you speak of and let you guys know how it goes. I do appreciate the help and replies!!

 

[nola mike]

Mine wouldn't with the composite timing cover. There was three covers used from 93 till 2010 steel, magnesium, and composite. The composite is so thick that the balancer sit maybe a 1/8 engaged before it hit.

The newer covers (except for real new) are composite. Again, the CPS reluctor might need to be removed