Prop Qustion?

[gypsy121761]

I have 40 hp Johnson outboar that I want to change my pitch for a faster top end. My question is ok, my prop now is 10.5 by 12 inch so which way would I go with the pitch to get a high top end speed? Can anybody help me with that, Thank you, Jess

 

[etracer68]

Re: Prop Qustion?

What is your WOT rpm, and gps speed?

 

[Haffiman]

Re: Prop Qustion?

It is not all about pitch. Type of prop, brand of prop, material of prop - it all comes into play. Need a pick of installation as well as rpm as mentioned above.

 

[AEROCOOK]

Re: Prop Qustion?

You should post your question in the prop forum here on iboats. The experts over there will be more than happy to assist but be prepared to answer a few questions. As etracer68 has pointed out, you need to know what your WOT RPM is so a tachometer is absolutely required. There is so much more to prop design than just the pitch and the wrong prop can damage your motor. I'm no expert so once again, try the prop forum

 

[F_R]

Re: Prop Qustion?

But the short answer to the question is you would increase pitch. A 12" pitch travels forward 12" with each revolution. A 14" travels forward 14" with each revolution. IN THEORY ONLY. The real world doesn't act that way at all.