whats the difference on 310 and 330 h.p 7.4 mpi
 

can some one tell me whats the difference on the two engines ? mine is a 1999 7.4 310 MPI noticed there are 330 HP MPI engines as well both look identical from what i can tell thanks vince

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

I think they are the same engine. The 330 hp is rated at the crank and the 310 is rated at the propshaft.

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

Correct, basically same motor inside..., I like the mark 4's better !

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

You guys are confusing with the old carb version, I think He's talking about the two MPI versions...

7.4 MPI had 310 HP at the prop
The 7.4 MPI LX had 330 HP at the prop... I heard the ECU was different... I don't think there was mutch differences in the internals... Maybe the heads?

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

Either way not enough power for me :D BBB

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

The 7.4 EFI Horizons had even more HP and were fresh-water cooled!

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

I think you are confusing with the INBOARD version witch is probably 10-20 more HP at the prop considering there is no drive but a shaft. The sterndrive versions of the Horizon had the same HP's than the standard blocs.

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

20 Hp

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

We knew you were smart..... :drink: :drink: :drink:

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

Sure, He's a SBRT Einstein.... :rolleyes: :D

Re: whats the difference on 310 and 330 h.p 7.4 mpi
 

Didn't the LXi (wasn't that like 1 or years? 1996-1997 maybe?) use a similar intake to the MAG giving it mismatched ports but that little bit of HP gain?

And/or, maybe peanut port heads?

Or am I thinking too much?? :D

Old thread but I been looking at 2 boats, 2001 Baja rated at 310 and a 1996 cobalt rated at 330. Both have the same 4200-4600 RPM range but intakes look different. Does the 330 engine use the same small ports heads or big ports which gives the extra 20hp? I just posted the engine photos on my FB page under name LARRY HANLON and/or PAWOODCHUCK

thanks

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I have had the engines apart seen nothing different, if there is anything betting its in the ECM, timing etc