Swap from 4.3 mercruiser to 5.7 Volvo Penta

Hi wondering if anyone can tell me if it is feasible to swap my current motor which is a 4.3 mercruiser with an alpha1 gen2 outdrive leg to a 5.7 volvo. friend has offered me the volvo which is in good shape and I would like the extra horsepower. it is driving thru an omc leg, but I would rather keep my current mercruiser leg (only done 270 hrs) if it is possible to do without too much drama. thank you all very much, cheers.

sharkman said:

Hi wondering if anyone can tell me if it is feasible to swap my current motor which is a 4.3 mercruiser with an alpha1 gen2 outdrive leg to a 5.7 volvo. friend has offered me the volvo which is in good shape and I would like the extra horsepower. it is driving thru an omc leg, but I would rather keep my current mercruiser leg (only done 270 hrs) if it is possible to do without too much drama. thank you all very much, cheers.

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Once you have the bell housing and flywheel / coupler compatability worked out, everything else is in a V-6 to V-8 swap pretty fundamental. The gear ratio on the drive may be way off too, gotta check that, but sometimes that can be compensated for by over-propping. The Alpha 1 Gen 2 is usually good for 300 HP. Use what you can from the Volvo and get / reuse Merc stuff that you need to get running. Wiring harness may be a little tricky. Are both units carb or Fuel Injected. Carbs make it a ton easier. If years are somewhat close, that may help, too. Check the spread and distance back between the risers to be sure the "Y" pipe will fit. May need Merc manifolds and risers.

It won't be cheap. from what I can see, but it'll work.

sharkman said:

Hi wondering if anyone can tell me if it is feasible to swap my current motor which is a 4.3 mercruiser with an alpha1 gen2 outdrive leg to a 5.7 volvo. friend has offered me the volvo which is in good shape and I would like the extra horsepower. it is driving thru an omc leg, but I would rather keep my current mercruiser leg (only done 270 hrs) if it is possible to do without too much drama. thank you all very much, cheers.

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Ayuh,.... There'd be lots, 'n Lotsa Drama,...

Slightly easier than stuffin' a VW motor into a Toyota...

bondo said:

Ayuh,.... There'd be lots, 'n Lotsa Drama,...

Slightly easier than stuffin' a VW motor into a Toyota...

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Thank both of you very much, from the sound of it it would be a much easier proposition just to use the OMC leg which the volvo is running thru now as the volvo is injected the mercruiser carby, cheers from Aus.

By the way this site is great.