99 42 staggered
 

how fast should a 99 42 staggered 500hp bravo boat run??

I would guess 70ish

friend of mine had one with sealed 500efis, ran 77-78ish

75-76

i figured close to the 80 area. a buddy of mine had 540's built and is going slower than he did with 500hp's we are just trying to figure out where he went wrong..... or why he isnt making the power.

I was talking with the man who owns one of the local custom boat shops, and he pointed out that Mercury Racing HP numbers are very different from engine shop HP numbers, such that a Mercury 600 ran faster than an engine builder's 900.

this 42 will only pull 5000 rpm's with 26 hydro's. the motors are new. the only thing used was the blocks and they stroked them to 540's with dart iron eagles (345cc), merlin intakes, 850 holleys, msd etc. never dynoed but i would think 650 hp. it runs 75-76 mph and that's it. very disappointed with the whole deal. what do you think, be honest, you won't hurt my feelings, it's not my boat. lol it's hard to believe that these motors won't make more hp than 500's

looks like we have another boater that should have left the stock 500's in their boat!!!!!!!!!!!!!:hitfan:

i bet the blocks werent the only "used parts":party-smiley-004:

Those are big heads (runner's). I would think that is where his problem lies. With a smaller runner it probably would make more HP.

sounds like he does not have the right combination of components.the heads have to big of runners for a natural aspirated motor . the problem he's having is no velocity of air in the intake system. the merlin intake manifold doesn't help that either. a brodix high rise manifold works much better. also the combustion chamber cc's have a lot to do with the initial compression ratio. the cam also has to work with all of these componets. i had a similiar problem with some 540's i had and all i did was change the heads. i had older chevy zl 1 alum. heads and i changed them to brodix bb2 x's and the motors never ran the same. i had to add superchargers to them to gain back the velocity that i lost by using those big runners on those heads. hope that helps you.