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[QUOTE=hullofjustis;4144019]
Originally Posted by supermx96
(Post 4143773)
I have a 29 single with a 525sc and i was run 68-70 mph gps, now i have build the engine with Bob Madara custom grind roller cam, ported alluminium head, 8:1 comp ratio, 468 ci block, BM 250 blower, twin QFT 850 marine carb at 9-10 psi boost with water/methanol injection estimate at arond 800hp runing now 80 mph gps turning a BBlade 26p lab at 5700 rpm.
With std height bravo drive that the center of prop shaft is at 7,375'' below the bottom of the hull. In 2-3 foot chop the boat start to chine walk.[/QUOTE I HAD 825 HP 5900 -6000 RPM -1 IMCO LOWER AND HAD THE BOTTOM BLUE PRINTED AND DID NOT CHINE WALK AT ALL, YOU MAY WANT TO CONSIDER RAISING THE X DIMENSION OR BLUE PRINTING THE BOTTOM I want to try a imco -2 inch next year. What prop did you have at this time 4 blade or 5 blade? And what drive ratio? |
I HAD A 26 4 BLADE BRAVO ONE 1.5 GEAR RATIO, NOW THAT I THINK ABOUT It I WAS USING 4.5LB BOOST ON THE DYNO and DROPPED TO 3LBS WHEN I PUT THE ENGINE IN THE BOAT. SO IT WAS PROBABLY ONLY MAKING 775HP. 7.375 below the bottom is really low but normal for a boat built then. you may even consider putting a -3 imco on or an imco extension box if you are looking for top speed. prop shaft i do not recall where that was on my 29.single, i have my twin engine scarab panther setup to be 3 1/4 below the bottom with std. length bravo and 1 1/4 below with shorties.
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This might be a dumb Q? But how or you guys measuring the prop shaft bellow the bottom? Trimmed all the way down or trimmed half way? Or what? I need to measure mine, I pretty certain it's stock!
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neutral trim. or propshaft at the same angle as the hull. tak a straight rule hold it next t the bottom (lowest point) of hull and put the propshaft at that same angle and drop a tape measure from rule to propshaft center
-------------- like that top line is lowest point of v on a single engine lower line is propshaft ------- you can measure one hull and put the identicl boat next to it and it more than likely will be different .propshaft height that is |
when i posted i guess the computer kept changing this but you get the idea
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got some news: after installing a new bravo X drive and a 25 Bravo 4-blade prop , with max trim, it`s about 65-68 miles fast
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is prop centerline higher on Bravo x than the Bravo 1
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Originally Posted by 01scarab29
(Post 4171759)
is prop centerline higher on Bravo x than the Bravo 1
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Originally Posted by Carsten41238
(Post 4171354)
got some news: after installing a new bravo X drive and a 25 Bravo 4-blade prop , with max trim, it`s about 65-68 miles fast
you stated a 25 pitch bravo one i have only ever seen even number bravo one props. |
Mine are Bravo 1's, 1.5 ratio, Twin 383's ,,,,, Were on the boat when new
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