prop shaft depth, x-dim
#1
prop shaft depth, x-dim
I realize they aren't the same thing though they get used interchangeably. On my little resin bucket the best I can measure the propshaft is 6.5" deep below the bottom of the little delta pad.
What is considered deep? How high can one realistically go? before needing a LWP? I have to take the transom assembly off anyways so I was thinking of going up 2"
Thoughts???
What is considered deep? How high can one realistically go? before needing a LWP? I have to take the transom assembly off anyways so I was thinking of going up 2"
Thoughts???
#4
Registered
I think around 5.5" is the highest you can go with a three blade. I was running 4.25" on a 12" box (so 5.25" at the transom if 12" back = 1"?) and my mirage plus had too much slip, 18-20%+. I had no water pressure issues with a dual water pickup bravo up to my 68-69mph top speed. Some guys take screws and plug upper holes of pickup. I like dual water pickups, upper holes can act as pressure regulator.
#5
I think around 5.5" is the highest you can go with a three blade. I was running 4.25" on a 12" box (so 5.25" at the transom if 12" back = 1"?) and my mirage plus had too much slip, 18-20%+. I had no water pressure issues with a dual water pickup bravo up to my 68-69mph top speed. Some guys take screws and plug upper holes of pickup. I like dual water pickups, upper holes can act as pressure regulator.
#7
Registered
6.5" is pretty deep. Especially if you're putting a big blower motor in it and spinning a big prop, that kind of depth creates a longer torque arm which will make the boat torque roll and chinewalk, etc. You can go to 3-4" no problem and still run a 4 blade and not have any planing issues. Most of the fast single engine v-bottoms (Howard, Lavey Craft, Hallett, etc) all set up their boats 2-3" or higher if the boat has big power. Mine right now (with a -2 lower) is ~4" and I wish I could go up higher.
#8
Registered
You need the LWP if you're going to raise the x-dimension like that. The other thing you can do is just run a transom mounted pickup to feed the motor and innercooler. An adjustable water pickup like Teague sells would allow you to dial in the pickup depth without too much drag, and it should provide more than enough water for the motor and innercooler.
#9
Registered
iTrader: (2)
6.5" is pretty deep. Especially if you're putting a big blower motor in it and spinning a big prop, that kind of depth creates a longer torque arm which will make the boat torque roll and chinewalk, etc. You can go to 3-4" no problem and still run a 4 blade and not have any planing issues. Most of the fast single engine v-bottoms (Howard, Lavey Craft, Hallett, etc) all set up their boats 2-3" or higher if the boat has big power. Mine right now (with a -2 lower) is ~4" and I wish I could go up higher.
Last edited by TxHawk; 04-09-2017 at 02:28 PM.
#10
Registered
Good info there. The west coast boats, some do some don't have a notched transom. Mine is notched and I'm still over 4" below, so I'm really too deep. Any issues getting on plane with your setup and a B1? Mine rolls on plane effortlessly which I like because I still ski and tube behind it.