Modify SCX Cav Plate
 

Guys, I've read the SCX thread and there still isn't a real conclusion cav plate wise.

Here is my problem. I took delivery of a new Lavey 2750 mid cuddy last August. I have about 25 hours on a 502 4.0 Whipple 1000hp. The boat runs about 100 with a BBlades 30 Maximus, cut hub, etc. Unless I trim very positively, I get a porpoise. This is not normal for this boat. Usually a very small bit of trim is needed. The same conditions apply to a 32 labbed B1 prop. I use a little tab and this strong positive trim to settle the boat at WOT.

I plan to take off the trailing edge of the SCX about 3 inches and maybe some width as well. The SCX extends about an inch further back than a Bravo and the SCX plate is enormous in comparison to the Bravo XR. I think that there is some leverage on the beaver tail trailing edge of the plate causing my problems.

I also notice that on gentle turns at 45 or 50 and above that a significant porpoise occurs. So, my jig saw awaits. This is relatively uncharted ground. Any strong reason not to try this?

Just a thought:

Have you ever taken video of your drive while running...I used a go-pro on the back of my boat and discovered that the cav plate of my SCX isnt even touching the water at speed. The spray from the prop hits it...but the plate itself is about 3 inches above the surface of the water.

Chris

How does the boat handle at 80-85 MPH?

Witch lower are you running? SCX or sc

I am running an SC lower....I believe Quent is also.

Chris

I agree with chris, the cav plate is not the problem. try a prop with less diamiter.

It may also be a balance thing...
I don't think you should need any tab in order to go fast.

Using some tab...means you are picking up the rear of the boat some.

Try taking two 60 pound bags of sand...and putting them in different locations in the boat.

I would try them at the rear first.

Chris

P.S. With the rear seat removed from my boat...it porpoises badly

PM KAP. I think he modded his SCX in this manner.

+1