Engine swap ....merc to Volvo

[Galbraitro]

Hey all! I’m a newbie to the site, but a long time reader that could definitely use your expertise!
ive got a 1995 searay Sundancer 370 with 7.4 mercs. They are coming out as they are tired, and I have access to two 2006 Volvo 8.1L engines. I understand that the the engine mount pattern is the same, but will these engines bolt right up to my transmissions? What will I need to replace/convert to make this work? Or should I look for mercs again...

thanks in advance

 

[alldodge]

I looked up both motors and rear bolt pattern are the same


Merc uses flywheel housing 865657A04
VP uses flywheel housing 3852831

496 Couplers and the flywheels are different then 7.4

Merc coupler bolts to outside edge of flywheel

VP coupler bolts to crankshaft along with flywheel

Without more info, it appears just use your coupler and bell housing, and replace the crankshaft to flywheel bolts to the size Merc uses

Also not: the 496 uses different exhaust manifolds then the 7.4

 

[Scott Danforth]

Head exhaust pattern is same between 7.4, 8.1, and 8.2 so the 454 exhaust can be migrated to the 496s. Hoeever the 496 exhaust breaths better

Flywheel bolt patterns are the same, however the 496 uses metric fasteners

Bellhousing pattern is the same, however the 496 is M10 vs the 3/8

 

[alldodge]

Head exhaust pattern is same between 7.4, 8.1, and 8.2 so the 454 exhaust can be migrated to the 496s.

There is sure enough info out there stating differently. Something about require drilling of new holes to make them work