Would like more fuel economy... 4 blade?

[htcheckler]

1) Would like more fuel economy
2) Aluminum 3 blade (not sure on the make)
3) 14.5? diameter with a 19 pitch
4) WOT= 4000 RPM?s
5) 454 7.8L, OMC Cobra drive with a 1:45 ratio
6) 25? 96 Four Winns 258 Vista with an average load around 7000 lbs.


I am looking for better fuel economy without sacrificing my cruise speed of 22-24 knots ideally I would like to cruise at or around 25 knots yet still get the same or better out of the hole. I?m not sure if a four blade or a three blade prop with a different pitch would work best for what I want.

 

[steelespike]

Re: Would like more fuel economy... 4 blade?

If your motor is 300 hp it will use about 30 gph(gallons per hour) at wot(wide open throttle).10% of the rated hp.
Yes a 4 blade should help you plane quicker,stay on plane at less power.And require
less fiddling to maintain speed.
Your best cruising speed could be anywhere from just on plane to 500 to 1000 rpm higher.trial and error or a flow meter are the only way to figure the best.
gph. If 4000 is your rated max rpm shoot for that if your rated rpm is higher you need to prop for that.What is your present max rpm and speed and the rated rpm?

 

[htcheckler]

Re: Would like more fuel economy... 4 blade?

Yes it is a 300hp motor, and my max rated rpm is 4000. My speed at 4000 is 27-29 knots a little faster if I trim it. My current cruise rpm is 3200-3500 which gives me 22-24 knots.