Dyno proven 675-700 HP 540CI recipes?
07-20-2015, 07:50 PM
#84
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Thanks for the clarification. Bent rods perform better with Ms Brittany Fountain Skank. In fact, they have to almost go in sideways as There is no piston, even custom, that will fill that bore.
07-20-2015, 08:06 PM
#86
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Have you tried any other props to see if it can pull any more rpms and get you closer to the power band IF it is up there higher? IF power curve shifted up a few hundred rpms and you had as much prop as boat could possibly pull previously maybe you have hit a point where it needs to rev a little more, just a thought, hope you find some resolution, I would think the tq band overall would be fatter but maybe not?
07-20-2015, 08:13 PM
#87
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Reason to ask lobe overlap is a prime key to big power numbers, but only if your are running good exhaust. Have ever heard that an engine needs a little backpressure, you might want to ask yourself why an engine would want an exhaust system that literally pushes exhaust back into the combustion chamber rather than sucking it out. The simple answer is, it doesn't. If a big-overlap, big-cammed engine has an exhaust system with any measurable back-pressure, the price paid.... big drop in output. That said that is a big cam, for a 5400 rpm engine, 6000 rpm engine, ok.
Looks like helping the OP on this post is not the point so I will exit, experts carry on...........
Looks like helping the OP on this post is not the point so I will exit, experts carry on...........
07-20-2015, 08:20 PM
#89
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that's next step and reasoning, I have pretty much come to conclusion the old engines just were stump pullers and these need the rpm....
Have you tried any other props to see if it can pull any more rpms and get you closer to the power band IF it is up there higher? IF power curve shifted up a few hundred rpms and you had as much prop as boat could possibly pull previously maybe you have hit a point where it needs to rev a little more, just a thought, hope you find some resolution, I would think the tq band overall would be fatter but maybe not?
07-20-2015, 08:22 PM
#90
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Reason to ask lobe overlap is a prime key to big power numbers, but only if your are running good exhaust. Have ever heard that an engine needs a little backpressure, you might want to ask yourself why an engine would want an exhaust system that literally pushes exhaust back into the combustion chamber rather than sucking it out. The simple answer is, it doesn't. If a big-overlap, big-cammed engine has an exhaust system with any measurable back-pressure, the price paid.... big drop in output. That said that is a big cam, for a 5400 rpm engine, 6000 rpm engine, ok.
Looks like helping the OP on this post is not the point so I will exit, experts carry on...........
Looks like helping the OP on this post is not the point so I will exit, experts carry on...........
