Time to dial it in, high slip %
 

Finally took the boat out today, everything went great, boat runs real well, but my slip numbers are way too high.
Hull:
82 excalibur Hawk 40, about 10,500 lbs, notched transom 18" x dimension, std bravo 1 drives, hp gimbles no boxes
Power :
454'S .030 over 9:1, 088 heads b&m 174 blowers
make about 590 each
ran 26p hydromotives spun up to 5150 rpm 66-67 mph top
was kinda hard to get on plane kept blowing out
cruise @ 3500 rpm 42-43 mph,
4000 rpm 49-50 mph
5150 rpm 66-67 mph
this was light on fuel 2 guys no equipment and the water was COLD!!!!! but air temps were high 60's
any thoughts ???? my next try was going to be 26 bravo 1's

that hull needs bravo's.....what are you looking for? cruise? top end?

i have extension boxes and went from bravo's to maximus b/c of slip and that made the difference....doesnt blow out as bad getting on plane and has a good cruising speed....im still not done

cruise would be most important to me, it's big, heavy, and lacking power so top end will never be big i would like to pick up 5-7 mph cruise and anything 70 or higher for top end would be great

At 5150 rpm/ 66.5 mph, I've calculated 21.33% slip. Personally I've never had good results with Hydromotives on old straight bottom boats. (other than Fountains) I think you will find your slip #'s much better with the B1 .

X-sounds pretty agressive for an old heavy V. at 18" X, it would put your propshaft about 3.75" below the hull. From my experience with straight bottom, notch transom Cigarettes, running Bravo style props. Slip #'s go up rapidly above 4.5". If you can get your hands on a pair of 1" spacers, I think you might be really close.

Good luck,

Kurt

i believe 15% slip or less will get me there but i'm at 26 now, if it will still turn a 26p prop

thanks kurt I think we have 1 I'll look

The Bravo One 26 will be far superior over the Hydro at cruise. I would not be surprised if you gained 4-5 mph @3500

Stay away from the Max 5 blade if you want to get any drive life at all with your weight.

Your at 26% at 3500 rpm, slip will be much higher at lower rpm's. In my line of work, anything above 18% WOT is unacceptable. With proper spacers and the B1 4 blade, you might just get it to 15% , if you can, that would yeild about 72 mph.

thanks kurt !! appreciate the input

Just a little word of advice. Do one thing at the time. Kurt is right on with the B1 but test props before you start playing with spacers, it's a mess doing everything at once.
Also, there is of course pros and cons with everything, but with your high x, you may find a maxie to be faster than a B1. However, your drives will take one heck of a beating as Kurt says. I'd still say it's atleast worth the extra 90 bucks for a 15 day test with your current slip.