3 blade speed prop suggestions? to go with my 20P 4 Blade

[Howard Sterndrive]

18.5 Bayliner/ V6 Mercruiser Alpha 1 Gen II

My 20P 4 blade Aluminum MIWHEEL prop gets me to 45mph gps @4700 rpm

I keep reading that 4 blade props sacrifice some top end speed for holeshot.

Looking for suggestion for a 3 blade Al or SS that would get me another mph or three

I guess 21P SS... or 19P SS.... leaning towards 21P

 

[fossill]

Re: 3 blade speed prop suggestions? to go with my 20P 4 Blade

14x23 was probably stock for that boat when new

 

[NHGuy]

Re: 3 blade speed prop suggestions? to go with my 20P 4 Blade

The guide says to run 4200 to 4600 rpm at wide open throttle. 4 blade 21 pitch of same model should get you down to 4500 RPM, which will be good for your engine and will give you a little bit of speed. If you want every bit of RPM and speed get a 23 pitch 3 blade. The fewer bladed prop will spin to higher revs due to less drag in the water. But the higher pitch will keep your rpms from going over the limit. Downside is you will need to trim in more for corners. Also your holeshot MAY take longer with the taller prop. Some of the holeshot efficiency loss will be recouped by going to SS though. SS props are more efficient than Aluminum as a rule. Keep the 20 aboard for watersports, big loads & emergencies.