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Conventional V-bottom hydronamics question..........

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Old 12-23-2007, 01:14 PM
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Originally Posted by Payton View Post
I don't see a pad. I see a notched transom. Which still should alow you to raise the drives a little. How much? I have no idea.
Sorry, your right, the 22 Velocity I had a also had a pad and I was remebering how squirelly it would get when I had it right on the " edge" with jack plate up and motor trimmed out. It was even more severe when I took the smalll hook out of the pad.

What are the thoughts on how I high I an go with lower units with the notched transom. Will their be adequate water pressure for motors if I raise loweres so bullets are in line with notched transom?? And I know I will lose a lot of bow lift, I guess all trial an error

And the reason I ask , the transom was set up for 30" centers.......I was thinking I may be able to go with 25"s all the way across.??? I have even seen 30's on centers and 20's on outers

Any insight would be appreciated
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Old 12-23-2007, 09:37 PM
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I don't know if there's anything that entirely works better than another........it's about the manufacturers preference to build conventional , single step, twin step and 3+ stepped hulls-then ultimately comes down to preference of the customer.
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Old 12-24-2007, 08:21 AM
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Originally Posted by BillR View Post
Jeff,
These pics look familiar?
I believe the dash is from your AT. The other is Thunder Dan's boat.

Back to the thread. . . . . .

both Dans..my gauge placement were different.
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Old 12-24-2007, 09:02 AM
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Now here is another what if for the thread;
Why arent the pad areas on boats running at speed done with a dimple pattern such as on a golf ball. The dimples would provide excellent lift and aeration as well as stability.
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Old 12-24-2007, 09:07 AM
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both Dans..my gauge placement were different.
. . . . . .that's right. Yours was the purple one on the floor at that time. . . . .?
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Old 12-24-2007, 09:08 AM
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Now here is another what if for the thread;
Why arent the pad areas on boats running at speed done with a dimple pattern such as on a golf ball. The dimples would provide excellent lift and aeration as well as stability.
Fountain did test that a long time ago, I don't know what the outcome was.
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Old 12-24-2007, 09:57 AM
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Where's the 38PP when you need them.
Every F-4 is a 38PP...albeit in highly modified form!! It was a great basis for a great hull.
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Old 12-24-2007, 10:00 AM
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Originally Posted by offshoredrillin View Post
Now here is another what if for the thread;
Why arent the pad areas on boats running at speed done with a dimple pattern such as on a golf ball. The dimples would provide excellent lift and aeration as well as stability.
Look at my spoon trick, it would create suction not lift - try it yourself you'll learn about hydrodynamics very fast.

First, have you ever done the spoon under the faucet trick? Where you hold the backside of spoon against the downward flow of the water and the spoon is sucked into the water further not pushed away?
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Old 12-24-2007, 10:26 AM
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Look at my spoon trick, it would create suction not lift - try it yourself you'll learn about hydrodynamics very fast.

First, have you ever done the spoon under the faucet trick? Where you hold the backside of spoon against the downward flow of the water and the spoon is sucked into the water further not pushed away?
yes, and thats the point...one spoon pushes, hundreds of them forcing the water out in different areas would creat aeration would it not? It goes along the same theory that smooth drives and skegs and bottoms are slower than satin finished ones, hence why speed wax was such a joke. To me it would cause more suction planeing, but at speed would be faster.
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Old 12-24-2007, 10:43 AM
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The spoon is sucked deeper into the water not pushed away, that creates a suction that in effect pulls the boat deeper into the water. So even if you put all negative dimples in the pad you have in effect created positive areas as well (higher than the depressions) whick I think should act like the spoon and create suction.

Your theory is very easy to test with a hinged board and a garden hose. It will not be exact but will either suck or push like the spoon and then you'll know for sure - hey it might work - try it!!!!!

As far as aeration goes in order to aerate you need to be able to draw air in from somewhere to make the air space?

Remember there were some early steps hulls that did not have clear access all the way to the chine? In the rise of the step they drilled holes and air was drawn from the top side some where. I believe, but not sure that some of the old Rybovich Runners (center consoles) had them and I thought a race boat named "Varn's Infinity" was like that as well. Neither worked as well as hoped but I'm sure there were many other reasons?
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