RUSSSR1

I am looking for ideas on what cam to use in my rebuilds. Unfortunatly I do not have any idea what was in there befor. The cams must have been custome ground, there was no I.D. numbers on the cam. The motors are set up solid roller.

Specs
Tall deck 4.500 X 4.000 = 509cid
Merlin "grumpy jenkins" heads 2.30int 1.88 ext 119cc
Arias pistons 18cc dome " should make it a little over 10:1"
Victor Jr. Dominator 1050
Crane roller lifters
Crane gold roller rockers
carrillo h beam rods

38 Cig Flatdeck SSM #III so she is a heavy pig. Last year I could only spin the motors to 4900rpm, gave about 67.5 gps. The boat had real good midrange power and not to bad out of the hole so I don't think I'm over proped just out of cam.

PatriYacht

Russ, how's life in Chicago? How far along is your rebuild? An engine like yours is a perfect candidate for a Crane 741. However, it wil then have a power peak up around 5600-5800. With your props 5600=79mph. I don't think 509's will make enough hp to pull them. So you will have to find another set of props or...... put some stroker cranks in those tall blocks.

RUSSSR1

Ian, Chicago is good. All my parts sans cams should be in town befor the weekend, maybe cams to if I can figure out what to run. So short blocks over the long weekend should be no problem.

The plan is for new 4.500 rotating ass. next year + .30 piston for 580cid

Would love to see 79 but that aint gonna happen with no torque from 509

PatriYacht

Check this thread for something about a cam doctor.http://www.offshoreonly.com/forums/s...ght=cam+doctor Apparently they can measure a cam and get it's specs. My guess is that it's a good size cam if it's solid roller. The rest of your engines are built to rev. Put in the 741's and prop it to turn higher. I have the perfect cams for next years engines if you are reusing the Merlin heads. Crane 651's with about 40 hours on them

RUSSSR1

Thanks Ian we will have to talk about next year