I have a searay 215 express cruiser with 5.0 mpi/alpha 1 with a 17' vengeance prop.

I was just wondering why everybody has 19-23" and me a 17.

what are the differences?

You need to be able to spin a prop in the max WOT range of your engine to get the best performance out of the boat. It takes more power or less weight to spin a bigger prop.

Theoretically a 17 pitch prop will move 17 inches with one revolutuion and so on with bigger props.

17 does sound small. I had a Chris Craft 208 with a 5.0. I used a 19 most of the time and a 21 if I was going on a long ride and wanted to increase my cruise speed.

Like Griff mentioned, you need to be at the upper RPM range for your motor.

searay215,

I have a 32 pitch 6 blade you may want to try on your boat. It will have a great cruise speed. (just kidding)

To find out if you have the right prop or not take your boat out and run it at wide open throttle. Adjust your drive trim to obtain max speed and then note what your rpm is. With your motor you should be somewhere between 4400-4800 rpm. Also note what your speed is at 3000 rpm and 3500 rpm. Note what your minimum plane speed is. Ideally you want the boat to turn 4800 @WOT with just you in the boat with light fuel on a cool day. In the summer hear with people, fuel, coolers, and suntan lotion on board you will still be in the rpm range of the motor.

Then depending on how you use the boat would dictate what prop you would want to have.

Typically with the kind of boat you have our customers are looking for a good cruise speed. In this case a nice 4 blade prop from Power Tech usually works well. You will find with the 4 blade prop that the boat will have a better cruise speed, plane at a lower speed, get on plane better and have better maneuverability around the dock. Your top speed should be real close to what it is now. The prop you have now is basically the Black Max Aluminum prop but cast with stainless steel instead of aluminum.

Matt

welcome aboard.oh!! You could try a Mirage plus as they have a large dia' than the veng.prop it helps the larger boats stay on plane at slower cruising speeds and the big blades really gives it good thrust on take off,I would try a 17Mirage plus if get the chance sometime.

Thanks for the advice.
havent had a chance to run WOT yet but will do as soon as i can and take note of the readings i get.

I will keep you informed

Thanks for the help

Thanks for the reply,We will be around if you need our help with any propeller dilemma.

searay215, that sounds like you are close now with your boat. I had a 21ft Maxum with a 17pitch prop at 4900rpm and it was right at our elevation (3200) Just listen to HOUSTONPROP and throttleup, because these people know what they are doing.

I had a 5.0 mpi/alpha 1 and the 17 was just right and if I wanted the low end power a 15 would really get on it, but it would run to many rpm's on the top end.

Thanks

We appreciate your confidence!

Thank you!

Julie