Its raining up here today. So a little more hp....did they just create that with more cam duration ( overlap ) , or better head design??? Would all of the higher hp 7.4's be like that even from crusader etc, did they all just buy crates from GM at specified HP then add there own stuff.
Wonder if they all have the offshore cast parts as well ??
Its raining up here today How did they make the extra power ,more duration ( overlap) or better head design ??Do all of the 7.4's at the same power do it the same way, I guess what I am trying to say is do all of them Merc, Crsader etc just buy GM crates at a specified hp then add their own stuff ??
If you change the hp/torque, then you also have to consider re-propping, maybe even heavier drives. And if you do a different hp long block, you can expect upgrading carburetor as well. And completely different manufacturer, then you have to change rigging and wiring. And if you have a closed cooling system, expect the need for more heat removal. And more hp means using more fuel.
If it were me, on a pleasure boat, I'd replace like-for-like, exactly.
I know all too well what horsepower and torque changes cost. Starting at 3 props at 3500 each. 6 carbs. and on and on.....
Thanks
Fred
1969 Glaspar Avalon /1967 Johnson Electromatic 85
1987 Carver Mariner
1988 Cougar Kevlar 46' with triple blown 572 ci
1995 Boston Whaler Rage
Past - 1988 2807, 1989 4207 Aft
waybomb wrote:QR_BBPOST I know all too well what horsepower and torque changes cost. Starting at 3 props at 3500 each. 6 carbs. and on and on.....
Now that sounds like some first hand add on pain....seems like its almost as much or more to change all the peripheral stuff. Believe that we would stick with the same power/ torque range as the originals though.
So a little more hp....did they just create that with more cam duration ( overlap ) , or better head design??? Would all of the higher hp 7.4's be like that even from crusader etc, did they all just buy crates from GM at specified HP then add there own stuff.
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