Pitch change no change in rpm

[david2027]

Changed the stock Black Max 14.25 x 21p to a Turning Point Legacy 14.25 x 19p. Engine is 3.0 Mercruiser recommended rpm is 4400-4800 but the BM showed 4200 @ 41 mph while the TP was 4200 @ 38 mph at WOT. I expected to gain 300-400 rpm with the TP. What gives?

 

[Bob_VT]

Re: Pitch change no change in rpm

It's all about prop design.......... the science of it will drive you nuts!!

 

[fossill]

Re: Pitch change no change in rpm

If you would have went to another Black Max the numbers would have worked in your favor. With a different manufacturer, you're looking a a complete different prop design so you have to start from scratch. Now if you take the numbers from your TP and repitch accordingly using another TP you should be good to go.