ratman

im putting some 1000hp blower motors in my 79 35 ft mistress around the first of the year, im running 1.48 to one #3 drives. my goal is to hit 100 or close to it. will four blades of three blades be better for this combination? threes are easier in the drives correct? any advice on diameter and pitch would be great, thx ratman

stinger390

When I bought my 390 Chris Craft Stinger it had twin 1000 HP blower motors and hit 100 MPH. It cruised at 70 - 75 at 3800 RPM spinning 15 1/4 inch 28P Bravo 1 - 4 blades through velvet drives and TRS's. The engines were rev limited to 6000 RPM and it would spin that easily.

I still have the props if you want them, and have been trying my luck on ebay with them, but a Cig 35 with the same power should be able to spin a steeper pitch 4 blade I would think. The Stinger is 10,000 lbs plus, and I'm sure you are much lighter than that. You might get 30P or 32P or even higher with your weight and that kind of power. I think the 4 blades give a better cruise performance at lower RPM with the same power, but might add a slight amount of drag at the top end. I am nowhere near a prop expert though, and I'm sure the real good advise will chime in.

Good luck,

Todd

throttleup

What is going to be the WOT rpm? Do you have adapters so you can use 26 spline #6 props? The pitch is going to be determined by the engine rpm.

If we were to assume a WOT rpm of 5600, a top speed of 100, a 32 pitch prop, preferably a 4 blade, should get you in the ball park. As far as diameter that is something that may be fine tuned but a good starting point would be in the 16.5" range.

I do have a test set of 16.5 x 32 4 blade 26 spline props you try if you wanted to.

Matt

bbladesprops

Finding the 19 spline props is getting much harder. Mercury doesn't advertise them and really doesn't like to make them anymore. We were still doing it when I left there but things are changing and I don't know if they will even make them anymore.

If you need adapters, let me know. I'm assuming your rev limiter will be in the 6000 rpm range. If you make hp in the high 5's, you'll need pitches 30 or below with slip% in the 12-13 range.

I guess without more information we won't be able to give the exact options. Let us know the approx. wet weight with your normal gear and people weight. Also, more info on the engines.

Thanks