Supreboat in

I got the new engine put in. We are prop testing now. We started off with a non labed 4 bladed 32 pitch from merc. I ran 86 at 5000 rpm. At about 15 percent slip. We sent the prop off to a local prop guy to have the blades thinned, balanced, labed. Got the prop back and we went backwards. 80mph at 5000 and 21 percent slip. Can anyone on here help me with what a good starting point would be. I'm hoping to get the prop slip down to about 11 percent and rpms up to about 5300 and I should be around 95 mph. Just need the right prop. The motor is a 572 cubic inch Merlin block. Aluminum 2x heads with port matched brodix intake and a quick fuel 1050cfm carb. I'm at 700hp and around 780 ft lbs torque. I'm running a xr upper and bravo lower with a 1.50 ratio.

OCCJoe

iTrader: (13)

I've read and studied Y2K's to the point that it would be considered an obsession . And as I've stated in other post , The 02 hull is going to need 850-900 hp to get to 95 mph . You would need 1000hp to see 100 . You were very close with 700/86 , I would think you could hit the 90 mark with the right prop and running on fumes .
You need to have a talk with your prop guy and have him rite the wrong . I think if you search the threads and look back in the Superbabi thread theres some prop testing info . Have you considered putting a shortie on . Most of the Y2K's are running the short's . They like the high X .
What are you going to turn your motor up too ? Is 5300 you target RPM ? Where did it make the HP and torque ?

Dave M

I've heard the opposite as far as shorties go. The guy who ended up with the "fasterdammit" tried a shorty, no luck. Pretty sure Eddie has tried about everything possible too. He told me shorties don't work.