Need Prop help/ Advise

**fireman24mn** · 09-05-2017, 10:54 AM

I have a 1977 Glastron CV-23. The boat is fully restored and I just got it on the water a month ago.
I have a 383 SBC with about 360 HP and 405 in torq. I am running a Alpha Gen 2 drive 1.47 gear. I have blueprinted the bottom of the boat and removed all the hook, sharpened strakes and the transom. I also raised the X-dimension by 2 inches. The boat is a v-hull with a pad that is about 2 ft wide at the back. The cavitation plate on the boat is about a half inch above the transom edge when trimmed down. The boat loaded and with fuel is probably around 22- 2400lbs

Props I have tried are

23P Turbo 3 blade. This was not even close to enough prop.

25P 4 blade Powertech TRO small diameter. I was at about 5800 RPM and 64.3 MPH(GPS)

Next 25P 4 blade Rev4 This gave me 67.3 and about 5,600 rpm

Next a Hydromotive 4 blade 25P This got me to 68.4 and still about 5600 rpm.

With the last 2 I had a good hole shot, felt great and drove nice. Putting these numbers threw a slip calculator I am at about 23% slip give or take depending on the prop. I am pretty sure I will need a surface prop like the hydromotive. Thinking I will probably have to go to a 27p and have the blade cupped to drop down my rpms

I would like to be closer to the 5100 rpm just to keep from spinning the drive to fast.

Anyone have any thoughts or suggestions on props to try? There really are not any shops around me that I have found(Minneapolis area) that have really anything over a 23p. I will probably be buying some props from here or eBay to get what I need.

Thoughts? Suggestions?

Thanks