Building a Sleeper
#71
#72
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Joined: Apr 2005
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From: Washington, MO
Not 100% sure, but I think Mark is setting up engine to max out around 5600 Sent him a text, so will let you know for sure. I know Bblades has a demo program, and I have a business UPS account, so I may demo a 28 and a 30 and see what works best
Thanks for your interest and help. We want to spend a week at Lake of Ozarks one summer. Seems like that place is Formula heaven!
Thanks for your interest and help. We want to spend a week at Lake of Ozarks one summer. Seems like that place is Formula heaven!
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.
#73
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Joined: Jul 2014
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From: Denton, MD
You're welcome! I love projects like this. Post some pics as things move forward.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.

#74
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Joined: Oct 2015
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From: Charlotte, NC
That's probably too much pitch. What maximum rpm are you planning to turn with the new engine?
BAM has a speed calculator http://www.go-fast.com/boat_speed_predictions.htm and prop slip calculator http://www.go-fast.com/Prop_Slip_Calculator.htm.
Running your numbers and assuming 5500 lbs loaded, 650 HP at the prop shaft and a 225 constant, it comes to 77 mph. Assuming you turn 5200 rpm and have 16% slip, a 28P prop puts you at 77 mph.
BAM has a speed calculator http://www.go-fast.com/boat_speed_predictions.htm and prop slip calculator http://www.go-fast.com/Prop_Slip_Calculator.htm.
Running your numbers and assuming 5500 lbs loaded, 650 HP at the prop shaft and a 225 constant, it comes to 77 mph. Assuming you turn 5200 rpm and have 16% slip, a 28P prop puts you at 77 mph.
#75
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From: Charlotte, NC
You're welcome! I love projects like this. Post some pics as things move forward.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.

#76
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Joined: Oct 2015
Posts: 243
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From: Charlotte, NC
You're welcome! I love projects like this. Post some pics as things move forward.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.
If the engine combination is set up to turn up to 5600 rpm for max power, you may want to start with a 26P. That puts it at 77 mph at 16% slip, which is realistic slip on a heavy, non-step V hull.
5600 rpm turning a 28P is 83 mph and a 30P is 89 mph. Both of which would be pretty optimistic.

#77
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Joined: Apr 2005
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From: Washington, MO
#78
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From: Washington, MO
#80
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From: Gibraltar, MI
Oh, and it's an OMC drive with a goofy 1.42 ratio...
Last edited by BBCLiberator; 02-26-2016 at 02:22 PM.



