Mercruiser 5.0 MPI to 5.7 MPI

[63A]

Currently running 03 5.0 MPI Bravo 1 in 21' Four Winns. Engine getting tired so I'm considering upgrade to 5.7. Prefer to build an engine instead of buy complete but cannot find data on engine specionss to duplicate stock 5.7 MPI longblock. Looking for valve sizes, head cc, camshaft lift/duration, etc to closely replicate 5.7 MPI. Another alternative is to replace 5.0 shortblock with 5.7 and rebuild 5.0 heads assuming heads for 5.0 and 5.7 are same (valve size and chamber). I know the 305 and 350 are externally the same but need specifics to build next engine.

Also- is 5.0 MPI ECU different from 5.7 MPI? Can 5.0 be reprogrammed for 5.7 if necessary?

Will 5.0 MPI ECU and fuel injection system support non stock engine parameters like hotter cam?

Any suggestions to find the above info would be appreciated. Tons of info on the web about tuning automotive EFI but can't find anything for marine applications.

Thanks

 

[Don S]

Re: Mercruiser 5.0 MPI to 5.7 MPI

Also- is 5.0 MPI ECU different from 5.7 MPI?

In general, no. But impossible to say for sure without a SN. Merc has everything from 98 to present by SN only, not year.

Can 5.0 be reprogrammed for 5.7 if necessary?

No

Will 5.0 MPI ECU and fuel injection system support non stock engine parameters like hotter cam?

Absolutely NO. The ECM has no way of know what parts you have in the engine. Only what info it was programed for.

 

[JustJason]

Re: Mercruiser 5.0 MPI to 5.7 MPI

The 5.0 and the 5.7 will have different ECM's. Different fuel injectors to. A 5.7 needs more fuel period, to run. It's electronics will be calibrated accordingly.