I have and 01 Sea Ray 280 Sun Sport with twin 5.7 260 EFI motors with Bravo Drives. Motors are stock at this time. Qustions I have:

1. What kind of longevity will I get out of the motors once boosted? They have 200 HRS on them now.
2. Should I just leave them alone and build fresh motors that are built for boost?
3. Should I go with a set of strong 383 motors and forget the boost? (seen some 425-475 HP motors) Not boosted....

The boat had optional 496 (425HP) mags when new so I know the boat can handle it and achieves close to 62-65 MPH with them factory. Currently I have had a top speed of 54 MPH. Pretty good for what it is. 9'6 wide 28 foot boat. I believe it weighs around 8000lbs.

Thanks in advance for any knowledge.

Mike

Boost is great but I don't think your 260s were built for it. Motor wise, it all depends on how fast you want to go, blown or N/A, how much money do you want to spend. Good running motors will need a good fuel system, probably some kind of headers, at some speed external steering. And when it's running really good you may start breaking drives.

I'm very into small blocks, but in cases like this, I would say big blocks are your answer. 8.1 take outs maybe..too.

I would be very happy with mid 60s. It's not a go fast but would like a little more.

With them already EFI motors could I not just put a better fuel pump in the tank?

From what your describing I agree with SB and say go the 496 HO take out route. You could have the boat as fast as you wanted it in a short amount of time and best of all it would be stock and an easier sell when comes time.

Thanks for the ideas guys, I have learned to ask a lot of question before digging into these little projects.

They are not like cars. The Merc/Volvo marine engines have the pumps external of the tank and rigged to the motor.

Did not know that. This is my first fuel injected boat and I have not really messed around with anything yet.

The long-blocks between the 5.7L (250 HP), 5.7L EFI (260 HP), and 350 MAG MPI were identical. Since the ECM has to be re-flashed anyway, I wonder if these could be made to work?

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