Simple Prop question

[stuartboater]

I currently have a 14 3/4 in 3 blade Stainless Steel 21 pitch prop on my Wellcraft Excalibur 21 sport. Has a 5.00 VP with SX drive.

My max reccomended rpm is 4000 rpm

Currently at wot I am running 3000 rpm when trimmed well.

I want to go faster, Plane well, and have good control in choppy waters.

Will the increase in rpm by going to a lower pitch (say 19 in) which will raise rpm give me better top end speed? Should I go lower?

Anyone with a simmilar engine and setup, what prop would you reccomend?

 

[Don S]

Re: Simple Prop question

Moving simple prop question to the prop forum.

 

[stuartboater]

Re: Simple Prop question

Edited

 

[05GlastronSX]

Re: Simple Prop question

Your pitch is way to big for that boat/motor combo, which is clearly indicated by your WOT rpms (unless something is wrong with your motor) Drop down to a 17 pitch prop, thats a heavy boat to be able to push a 21 pitch prop. I have a feeling the 17 will put you in the WOT rpm sweet spot. Also, you want to run your motor to the upper end of the rpm range. For a SBC 5.0, im guessing that would be around 4600.

Also, do not keep running your boat at WOT the way it is, its lugging the motor and is terrible for its longevity. You need to switch props ASAP. By dropping down to a 17, you will gain a lot of RPM's and overall performance, since your motor will be able to run to its designed RPM range and allow you to take advantage of its powerband, which your not using at all with the current prop, thus why your performance is poor.

 

[stuartboater]

Re: Simple Prop question

Thank you very much for you help
Much appreciated

What about this prop

http://boatpropellers.iboats.com/Vo...404978&**********=027952581&*******=149058065

Do you think it will do the job?

 

[05GlastronSX]

Re: Simple Prop question

I cant tell you for sure, youd have to try it out and see, but that potentially will be a lot better (at least putting your motor in the proper rpm range). Its cheap enough to try out and either sell if you dont like it or keep it as a spare.