To many RPM's

[duffster]

A 28 foot Warlock deckboat. Weight about 4800 lb
I would go with 30's running HP500.

[TilliamWe]

If all your info is accurate, and you think the engine could turn 6000rpm with the 26s, then yup, I'd go all the way to 30. That should lower your rpms right into the 5000-5200 range, right where BadKachina says it's supposed to make it's power. Good luck to ya!

[U.T.B.A.V-Drive man]

I went into the prop calulator. I don't think this is right. This boat won't go that fast. I wish it could, buy I don't think so.
RPM=5400
gear=1.5
pitch=30
weight=4800
lenght=28
slip=.15
speed= 86.9

[duffster]

I went into the prop calulator. I don't think this is right. This boat won't go that fast. I wish it could, buy I don't think so.
RPM=5400
gear=1.5
pitch=30
weight=4800
lenght=28
slip=.15
speed= 86.9
The prop calculator is only good for single prop applications you are most likely running 2.0 gears with the B3. If you go with 30's you can always cut the down or add to them. With the 2.0-B3 and my new 502 EFI Mag with pitched to the max labbed 28's from Bronson Hill my 3000lb 21ft will only do 70mph at 5100. If I was to go 1.5-B1 with a 24 pitch single it will do 75+.