X dimension ?
 

I have a 1987 Four Winns Liberator 241. It was a 350/alpha. It was converted to a 540/bravo. My engine makes 585hp and 620 ft lbs. My gps speeds are only about 65-66 with a light load. I currently run a labbed 26p bravo prop. Its turning about 4950rpm.

I think something is holding me back. I measured the distance from bottom of keel to center of prop shaft and its 7 1/2 inches. The boat gets some chine walk at full speed. I could trim it almost too the trailer posistion and throw a rooster tail and it still doesnt blow the prop out.

The question is, is running a four blade that deep in the water holding me back on speed and rpm? Should I go with a 3 blade? Or maybe a shorty lower? I would like to see 70mph all day with this boat.

Re: X dimension ?
 

Two words: "Imco Shortie" --- JP

Re: X dimension ?
 

You have 2 options the Imco Short lower or a stand off box....

Re: X dimension ?
 

absolutly try a 3 blade prop........you use a 4 blade when your x dim. is high and you need the xtra bite that the fourth blade provides.......a Bravo One prop is semi surfacing design.....that is the prop blades are made so they can come out of the water a bit on the top of the rotation and not loose bite.....high x stuff for sure.......one of, if not thee fastest 3 blade prop........Mercury Mirage or Mirage Plus.......doug

Re: X dimension ?
 

Yes, the right Mirage could help some. It be worth a try if you can find the right one to borrow. But I still think that the set-up guy "missed the boat" by not raising everything when the Alpha/Bravo conversion was made. Again; simplest fix now - Imco Shortie. --- Jp