2.5L vs. 3.0L Mercury

[J Blake]

I am trying to get educated as my need for speed has taken over! I just upgraded boats from a 77 Ventura II w/150 Merc to a 21 Checkmate Pulsare w/ 225 EFI 3.0 L . Top speed on both boats is the same at 69 mph. I see that the 300 Promax is a 3.0L engine like the 225 EFI. However the 225 Promax is a 2.5 L as well as the 2.5 which makes 280 Hp. It seems to me that a 2.5 L size engine has to work harder to make 225 or 280 hp. What type of upgrades are available to improve my 3.0 L 225 or to make it like the 300 Promax. Also when it comes to turning rpm's what is different about all these engines that let them run from 5800 stock or upto 7000 like the 2.5 L

Please enlightenment me!!!

[vector mike]

The 2.5's have a different port timing and a much higher rev limiter and ECU. I think they have forged pistons versus cast in the 3.0 too. The 2.5's also have lightened flywheels. They are much higher spinning motors that are mostly designed for light weight boats where alot of torque is not a concern. Maybe someone else can jump in here with some more knowledge and totally fill you in about them. :)

[Promax300]

call wayne taylor at www.madefi.com he has all the goodies of the 3.0s and also tony brucato at http://www.brucatosvs.com/