Diameter vs. Pitch
 

Can someone tell me in layman's terms, what the relationship between prop diameter, pitch, and speed is? Is the difference in diameter of the same pitch prop proportionate to slip?
Thanks,
Dumbo

Ayuh,..... Generally speakin',.... Prop diameter goes up, as pitch goes down,....

Blade design plays a bigger roll than diameter,.... especially with efficiency/ slippage,...

The larger the diameter the prop will have more blade surface area thus creating more effective (higher) pitch. So say if you have a prop with 14 7/8" 32pitch and another prop with 15 1/4" diameter 32p, the larger diameter will be lower rpm and act as if it were a larger pitch than the smaller diameter prop even though they are both "labeled" as 32 pitch. Larger diameters can offer benefits when needed such as lower slip numbers on high x boats and also minimize blowout

Thanks for the info!

Diameter is good, when its needed, bad when its not. I think you'll find on boats where the propshaft is deep, adding diameter usually will slow the boat down at top speed. Kind of like on a boat where 3 blades are the fastest after realizing 4 or 5 blades just slowed it down.

Larger diameters and blade area don't increase pitch. I think what you were trying to say is larger diameters can slow down your rpm due to more drag and from surface area. The horsepower to turn the diameter is larger. However, your forward travel is still the pitch of the propeller.

More diameter creates more stern lift. We use diameter in a variety of set up desires.
As manufacturers of propellers, we determine the best all around diameter for any given propeller design based on its most common usage. As custom propeller tweakers, we adjust that diameter when needed to get the affect desired.

There is a ton going on with diameter adjustments.

Brett

So if you take it out and that does not work out so well, Can you put it back in?

unfortunately, no

Sorry I missed this response.

Actually you can weld on diameter but it is not a very good idea in performance applications because of the risk of failure.

Brett