prop diameter ....

[deejaycee_2000]

is it better to have the max diameter prop that can fit your gearcase? I am ordering a 20p racing cleaver for my 50hp yamaha, the max diameter that will fit is 11 1/2 ..... is it advisable to go that much diameter or should I go smaller?

 

[ivar]

Re: prop diameter ....

As I understand, more diameter allows you to raise the engine more without losing grip in the water

 

[Silvertip]

Re: prop diameter ....

Diameter is just another factor when selecting a prop -- but not the main factor. While a slightly larger diameter prop may work better than a smaller diameter prop from another manufacturer there is no guarantee. Props are designed with a given series of engine HP and gear case sizes in mind. Therefore you find a specific range of pitch selections for a given engine. Within that range you will notice that diameter goes up and down as the pitch changes. Generally diameter decreases slightly as pitch increases and vice versa. Larger diameter means the prop likely has more blade area. In some applications that may be a benefit and in others a drawback. While there is no answer in all of this, I think you just need to try it and see.

 

[MikDee]

Re: prop diameter ....

As silvertip said, diameters vary according to pitch, and manufacturers, generally on a light boat you don't need extra diameter, on a heavy boat with a heavy motor, like an I/O you may need extra diameter to keep from falling off plane in a turn, or a better hole shot, as I have personally found.

 

[MikDee]

Re: prop diameter ....

is it better to have the max diameter prop that can fit your gearcase? I am ordering a 20p racing cleaver for my 50hp yamaha, the max diameter that will fit is 11 1/2 ..... is it advisable to go that much diameter or should I go smaller?

Also most motors of that horsepower range seem to use a 10" dia prop standard, 11 1/2" is not that much bigger when you consider the average prop for an 85-150hp outboard is 13-15" diameter, plus I bet there's a lot less blade area on that sleek cleaver, so they have to make up for that by increasing dia. a bit.

 

[deejaycee_2000]

Re: prop diameter ....

thanx for the info guys, I appreciate it ......

Ron Hill is building me a racing cleaver ...... anyone own one of his props?