View Full Version : prop size?
maxum
05-21-2007, 05:14 PM
can you tell me the best size prop for my boat?.
i think im under prop .(is that what you call it) it revs to much and not that fast.
i just put in a 5.7 350engine new not run yet. so i will like to do this job the same time
and stop the over rev.i cant tell the size is on it now.drive is alpha one gen 2.
2300sc maxum,thanks.
Jango
05-21-2007, 08:02 PM
We need to know:
1. size of boat - length, width, bottom shape (deepV, flat or somewere inbetween)
2. Total weight w. one passnger (driver) half tank of fuel.
3 Brake HP @ what RPM
4. Final Drive ratio
Whatever else you can tell us will help.
Jango
maxum
05-21-2007, 08:50 PM
ok its 24 foot about 2000lbs ,3foot draft, hp260 engine 5.7 vortec q,jet carb
alpha one gen2 drive.me my wife and my 2 kids
maxum
05-21-2007, 08:53 PM
width about 8 foot.
Jango
05-21-2007, 09:50 PM
I believe your total weight of 2000 lb is a least 600-800-lb low. The motor/outdrive alone is more than 900 lb.
Without more precise details it is difficult to recommend an exact Prop.
Based on similar applications, I would suggest a 14 or 14 1/2 x 19 P. 3 Blade prop. I believe a 21 pitch will probably not allow adequate max RPM. (4400)
Jango
05-22-2007, 12:34 PM
Just figured prop requirements for a boat similar to yours:
1. 24' planning hull, 3000# w. Driver only and half tank fuel.
2. 260BHP mercruiser @4400rpm (5.7L)
3. 1.5 gear ratio
Calculated to 15 1/2D. X 17P Full Cup, 3 Blade (.55 D.A.R.) w.10%slip - Max Speed, 44 MPH
maxum
05-22-2007, 06:39 PM
hmm i see.hull spec is good for 50mph.got it out today prop size,4878120a40 19p.?
Jango
05-22-2007, 07:11 PM
Weight is extremely important in determining Prop size. If boat with Driver only, with minimal fuel was 2400 lb, prop size will be 15 1/2 D x 19 P. Full cup w.10% slip. Max speed 49.2
View Full Version : prop size?