Merc 454 Mag to Volvo 8.1
 

Does anyone know what will have to be changed to go from Merc 454 Mag to Volvo 8.1 power. I have a friend that is facing a repower right now and has a line on a pair of Volvo's. I assume at least exhaust, but what else, drives?

Thanks, James

Re: Merc 454 Mag to Volvo 8.1
 

TTT, someone must have some knowledge????

Re: Merc 454 Mag to Volvo 8.1
 

If you're changing the drives to VP you need to cut new holes in the transom.
If you're not changing the drives you have to change flywheel housing and coupler to fit the Merc drives.
Electrical harness is different, but you can get connectors from CP performance.
I think VP 8.1 have direct drive raw water pumps but that would not be a problem, just some new hoses.

Re: Merc 454 Mag to Volvo 8.1
 

Thanks 38KV!

Re: Merc 454 Mag to Volvo 8.1
 

I did it and the only things you have to change are the engine coupler, bell housing and engine mounts. All of this comes off your old engine. As for the electrical stuff your 10 pin will plug right up the only mod you need to do is splice four wires on the back of the motor for your tilt and trim senders. The volvo 8.1 is an excellent choice and changing the raw water pump is much easier than merc.

Re: Merc 454 Mag to Volvo 8.1
 

muffman, thank you very much for the info! That is good news for my buddy that is repowering.

Did you get the 375HP or 420HP?

Re: Merc 454 Mag to Volvo 8.1
 

I actually bought the 375 for less and then installed the 420hp camshaft and had the pcm reprogramed to the 420hp specs except they turned the rev limiter up to 5250 rpm.