hwsiii can you do slip formula for a 4 blade

[junior1113]

i lost the form you e-mailed me 1993 hydra-sport 2000 cc 20" 1993 200hp evinrude ocean pro 1;1.86 14.25x17x4blade turbo ultima. 5800rpms @ 48 mph, 3500 rpms @ 25 mph . 4200lbs with persons motor and gear. have went through 4 props and this is the best one. thanx-paul

 

[hwsiii]

Re: hwsiii can you do slip formula for a 4 blade

Paul, here are your prop slip numbers, and they are excellent.

Prop Slip

H

 

[junior1113]

Re: hwsiii can you do slip formula for a 4 blade

wow 4%. gps was like 47.7 whats the difference when doing the formula on a 4 blade. would'nt it travel more than 17'' per revolution just curiuos. also this thing is very agressive with lots of cup

 

[hwsiii]

Re: hwsiii can you do slip formula for a 4 blade

Paul, there is no difference in number of blades on a prop in the calculations, I am sure the prop has cup in it which adds theoretical pitch to the prop which means you are not really getting that little of a prop slip. But, normally it requires less drop in RPM to Cup a prop, rather than add pitch, diameter or change blade geometry dramatically, that is why it is still deemed a 17" pitch versus a 18" or 19" and the turbo ultima is an excellent prop.

H

 

[junior1113]

Re: hwsiii can you do slip formula for a 4 blade

thanks guess this is as good as this boat is going to do with this motor. yea dhadley got me this prop for a good price said it was awsome and i agree

 

[hwsiii]

Re: hwsiii can you do slip formula for a 4 blade

That is wonderful Paul, Dhadley has a tremendous amount of knowledge and is always helpful to people.

H