Engine Swap - 4.3 to 5.7

[bhammer]

All, I have a buddy that wants to swap a 4.3MPI to a 5.7MPI. He doesn't have anything 5.7 and would aquire a rebuilt long block marine engine and peice it together. Has anyone done this? I am sure that he can find the manifold, ECM and parts. Anyone know if the monts line up? Wire harnesses, throttle and shifter? Anyone ever do this swap? The boat had a 5.7 as an option originally so I think it's rated.

 

[dubs283]

Re: Engine Swap - 4.3 to 5.7

the boat might be rated, but the drive isn't - wrong gear ratio

need a different drive or new upper gearset in the current drive

 

[bhammer]

Re: Engine Swap - 4.3 to 5.7

Good point, he'll need to gear properly. I wonder if the gears can handle it in his current drive if he just props up a WHOLE bunch.

 

[Pete104]

Re: Engine Swap - 4.3 to 5.7

Have HIM try & let us know! We need a good laugh once in awhile!

 

[cr2k]

Re: Engine Swap - 4.3 to 5.7

Well if "props up a whole bunch" it will take him half the lake to get on plane. You know like doing a "burn out" in 3rd gear. The prop could ventilate easily out of the hole.

 

[Bondo]

Re: Engine Swap - 4.3 to 5.7

and would aquire a rebuilt long block marine engine and peice it together. Has anyone done this? I am sure that he can find the manifold, ECM and parts.

Ayuh,.... That's a good way to spend 10 grand for a $5,000 motor...

The front motor mounts need to be moved forward, 'n he'll need a replacement drive...
Repropin' won't get it...

 

[wca_tim]

Re: Engine Swap - 4.3 to 5.7

do some searches, this has been talked throuhg a bunch. cr2k, while 'propping up' isn't the answer for every situation like this, you obviously haven't tried it. With the range of modern props available you can easily get a v8 with a 1.8 gear propped right until your speeds get deep into the 70s. (you run out of available props around 80 mph depending on how fast you turn the engine). keeping the engine cool and the drive holding together are separate issues that also bear careful consideration.