help with engine block swap

[scottietoohottie123]

hello everyone,
so im in a problem situation here i have a 96 wellcraft with a 5.7 mercruiser that a exhaust valve fell into a cylinder and crumbled the topside of the piston while grooving the wall about a 16th of a inch in 4 places so i pulled out engine and bought a older 4 bolt main block not knowing that it has a 2 piece crank instead of a one piece like the original engine...my question is what do i have to do to make it work with the flywheels being different? my alpha 1 gen 2 coupler wont bolt up to the new flywheel.do they make a adapter?

 

[Bondo]

Ayuh,.... Welcome Aboard,...... What's the pattern of yer coupler,..??..??

 

[Scott Danforth]

I would sell the older motor and build a vortec headed stroker

If your motor is a 1996 and not a 1995, you have other issues besides the 2-piece RMS. You basically bought a motor 2 generations older than the motor you had

 

[scottietoohottie123]

so you have no answer to my question...you just want to tell me what i bought and what i should do? and what other problems are you talking about? you sound like you have billions of dollars to just build whatever. i mearly just wanted to know what i needed to do to couple up the drive with motor.

 

[Scott Danforth]

They don't make adapters

You might be able to buy a different coupler. What bolt pattern is your current coupler

Your current motor is most likely a vortec headed V8, so your current intake won't fit the old generation motor

 

[Scott06]

The two piece uses this coupler That bolts to crank hub

MerCruiser Hub Style Coupler (1985-Earlier)

This coupler is used on pre-1985 MerCruiser 350 ci or 305 ci engines, with what is commonly called a "two-piece rear main seal" or "split seal".Replaces MerCruiser part #76850A2

www.michiganmotorz.com

other diffs are the starter bolt pattern. I believe your original engine will use a 14” flywheel with staggered pattern , replacement engine will use the 12 5/8” flywheel with straight pattern. So you likely need a new starter.

also if you are using the complete long block your intake bolt pattern is different. 96 is the cross over year to vortec heads with their 8 vertical bolt intake. Either way the 86-95 intake is different from the pre 86, so you likely need a new intake.

you may not have liked Scott’s answer but he is right…Other issue is if you swap later vortec head engine for earlier non vortec head engine you will also be loosing about 30 hp. You will likely feel that in. Seat of pants and probably need to drop prop pitch.

so it Does make sense to question vs giving an ear full, how much effort to put in an older generation engine that makes less power if you are loosing vortec heads and has an older more leak prone seal design.…

 

[stresspoint]

hello everyone,
so im in a problem situation here i have a 96 wellcraft with a 5.7 mercruiser that a exhaust valve fell into a cylinder and crumbled the topside of the piston while grooving the wall about a 16th of a inch in 4 places so i pulled out engine and bought a older 4 bolt main block not knowing that it has a 2 piece crank instead of a one piece like the original engine...my question is what do i have to do to make it work with the flywheels being different? my alpha 1 gen 2 coupler wont bolt up to the new flywheel.do they make a adapter?

NO!.

 

[Bondo]

so you have no answer to my question...you just want to tell me what i bought and what i should do? and what other problems are you talking about? you sound like you have billions of dollars to just build whatever. i mearly just wanted to know what i needed to do to couple up the drive with motor.

Ayuh,..... It would help if you answer our questions,....

What style coupler do you have now,..??

What size flywheel are you attempting to use on the replacement motor,..??
Is the block drilled for both starter patterns,..??

 

[alldodge]

so you have no answer to my question...you just want to tell me what i bought and what i should do? and what other problems are you talking about? you sound like you have billions of dollars to just build whatever. i mearly just wanted to know what i needed to do to couple up the drive with motor.

Welcome
Answer questions post 2 and 8 and get answers

 

[Cali_Boat_Guy]

I have had vortec engines in two pickups and both had problems with oil pressure and lifters. I don't know if this carries over to marine engines, however, newer isn't always better.