1989 272
 

I am repowering my 1989 272 . Current power twin 454\365 looking into the merc dropin 383\350hp mpi , don't want to lose any top end but the all new and mpi sounds great to me! anyone out there have any 272 with this engine combo? what are your cruise and top end #s also what props? thanks

Are the mags original? Performance sheet for 89 only shows 350mag or 330hp 454 non mag. Thought 454mags came out in the 272 in 90.
Why repowering? If the mags are tired why not rebuild?

I think the boat would be better balanced with small blocks and if it already had 350s I would say go for it.
but since it already has big blocks I think you wI'll miss the torque. My guess with those 383s is 65mph. You will need a smaller prop, probably 23 vs the 25 I assume you are swinging now and hence you will lose cruise speed.
Let us know the results if you do it, I'm interested.

The current engines are 454 /365 mag says the flame arrestor covers. I have owned the boat 6 years, has stainless marine exhaust no other upgrades. lost port engine due to manifold failure (they were on the boat when I bought it) broke a rod bent the crank and hole in the block. current speed is 68 spinning a pair of 25 mirage plus. I am thinking that the lighter small blocks will help reduce bow lift and give a more even ride.
Dose anybody have a 272 with mild built small blocks real numbers?

I have two 383's that I just pulled out of my 242. They are almost new. Maybe 25 hours. Would you be interested in them? They are carbed. Not efi.

More info on the 383s and their location please.

Are you over trimming it? I never felt that mine had too much bow lift and that can be adjusted with props. We did that swap to a 29 scarab, seemed to work out well but not as fast as it was with 385 mag mpi's. It does use quite a bit less fuel.

Pm me your email and I will send you some info. Located in Pa.

I am a previous owner of a 1988 272. We replaced carburated merc 350 mags with [new at the time] 350 mag mpis rated at 300HP ,1.47/1 alphas and 23 mirages. Acceleration was strong but this boat was hard to push to higher speeds. 61 MPH on GPS was top speed. In hindsite it would have been better to go to big blocks and have the torque to get a higher top speed.

used to be a 272 local with 383's that would get 68/70, lots more room to wrench then the BBC

I had a smallblock 272sr1. Great boat. Plenty of power 57-58 all day. Best of 63. Great boat.