32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
07-10-2006, 12:20 PM
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32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
I have a 31' Corsa, with a BBC 598CI, 600HP. Bravo drive, the boat is front heavy, I cannot get the bow up. Any sugestions ? Boat is doing 62MPH at 5000 RPM, I have tried 5 blade, 4 blade, 23" pitch, to 28" pitch props all the same speed - but RPM changed a little. This boat is plowing the water at 60 MPH: HELP ANY SUG { ?????
07-10-2006, 12:42 PM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
My cig bullet weighs 8900 dry and runs in mid to upper 70 with 565 a side and is very bow heavy
Have you indexed your tabs and drives to nmake sure they are in the position you think they are at?
Have you indexed your tabs and drives to nmake sure they are in the position you think they are at?
07-10-2006, 06:24 PM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
What is your X dimension? I have a 30' single and also need bow lift. I installed a drive spacer and it helped.
07-10-2006, 06:25 PM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
Originally Posted by BY U BOY
Check The Hull For A Hook.
Your 31 corsa is varey close to my 34 Super Hawaii, if not the same hull. I know mine came from the 30' Corsa. I found a very small hook, maybe 1/8" in the last 4" of the hull. I took it out and gained 200rpm and 4mph. I seemed to be plowing water last year. Now I am on top and loving it.
07-10-2006, 09:24 PM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
I never did any indexing, the bow looks straight, ran the boat last year with a 454/365 and a king cobra and it ran 50 MPH all stock. I doubled the HP and put the bravo on and gained about 13 MPH. No bow lift at all. I have about a 3" drive rise at the transome. I have used cupped props with no luck also.
07-11-2006, 12:37 AM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
How far is the propshaft below the bottom???? I would think you would need to be around 5" below the bottom to get enough leverage.
I would try adding a drive spacer.
I would try adding a drive spacer.
07-11-2006, 06:28 AM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
Mine looked straight. Take a 4' level and place it several places on the bottom, at the transom and up to 8' foreward. There should be no air gaps on the level.
07-11-2006, 07:20 AM
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Re: 32' V-Hull BOW LIFT PROBLEM - 598 BBC 600+ HP HELP OUCH
Supper Air,
when you check a boat hull for hook..
1.) Mark a spot on the keel.. about 10' forward of the transom
2.) Draw a line from that mark to each back corner of the boat at the transom. This forms a triangle. Which should be your running surface at speed.
3.) Using a 6' or longer straight edge, check all surfaces to be flat within the triangle. Air gap in the middle of the straight edge = hook. Air gap on the ends of the straight edge = Rocker.
The rule is that all surfaces should be flat and symetrical from side to side, unless the hull was designed with hook or rocker built in for some reason.
Another thing to look for is water in the hull.. I have heard of it happening and a few extra pounds in the front can make a difference..
Hope this helps.
Dick
when you check a boat hull for hook..
1.) Mark a spot on the keel.. about 10' forward of the transom
2.) Draw a line from that mark to each back corner of the boat at the transom. This forms a triangle. Which should be your running surface at speed.
3.) Using a 6' or longer straight edge, check all surfaces to be flat within the triangle. Air gap in the middle of the straight edge = hook. Air gap on the ends of the straight edge = Rocker.
The rule is that all surfaces should be flat and symetrical from side to side, unless the hull was designed with hook or rocker built in for some reason.
Another thing to look for is water in the hull.. I have heard of it happening and a few extra pounds in the front can make a difference..
Hope this helps.
Dick
