Just ran my boat (32 AT) yesterday after playing with the motors all winter. Cruised around for 20-30 minutes and let er rip. Picked up 7-8 mph (79-87) with Marine Kinetics 600's upgraded from carb 500 HPs. Ran 30" borrowed Bravo I props up from 28" Bravo I's but still hit the rev limiter on the port motor. Looks like I have room to move up with props. Also, water in the river here in LA was slick calm yesterday and I generally run best in a 1-2 foot chop.

With the cam selection from RMBuilder the boat accelerates like a scalded ape from 3500 to 5300, the GPS can not keep up.

Motors idled at 700-750 with smooth acceleration, no hesitation and no problems so far.

I can not emphasize how much help RMBuilder, Bob Madara was on this project. Bob I could not have done it without you buddy.

Tom

Tom,
Great numbers on what really matters, how the boat actually performs. I would be very happy with those improvements.

HP 500 sleeper 600 update:
I ran one of the motors today and got 620 HP @ 5500 rpm on the first pull, made some jet changes and spacer changes and it ended up that the first pull was the best one. The TQ came in at 602 FT/LBS @ 4800, a little higher on the rpm than I expected, but 589 FT/LBS @ 4400.
This combo includes the original 800 cfm carb (with a little work), Dart 6200 intake ( with a perfect match to the heads), and Gil exhaust. I ran a top secret fuel ( Marathon 89 winter blend). I am verry happy with the results and can't wait to get some numbers from the boat.
I also would like to thank Bob Madara for all his help.

Congrats to you guys on your new power----for naturally aspirated 502's those are some pretty healthy numbers. If they were my engines I would be very happy!

Wags,
Those are nice numbers. Should be a nice pair of bullets for the boat.

Chris

Chris,
Thanks for the compliment. You were right the Morel lifters worked flawlessly. The motor liked the original stagger with the jetting with just a couple sizes larger than stock. When we tried to square up the jetting the power fell off.
We did not experience the tq dip that some of the other 502's had, it started at 571 ft\lbs @ 3300, made a steady climb to 602 ft/lbs and made a steady drop to 592 ft/lbs @ 5500 rpm.
The motor still looks like an HP 500 and the idle sounds mild like it did before, but when you crack the throttle open it deffinatly has a much stronger sound to it. Jeff

Care to share the parts list and cam specs that got you there?
Thanks

Wow, Awsome results. I guess you will be even further ahead of me this year. Congrats

305cc AFR heads
Edelbrock 454R intake
950 cfm Holley
cam by RMBuilder
Morel Lifters

RMBuilder has the specs and dyno info. Maybe he will chime in.

wags,
post some cam specs and other specs..

whatd you end up with for jetting? what other changes to carb?
im basically doing the same setup only with iron ported heads, not the nice pieces you have!!!

thanks
kevin

Engine specs:
stock HP500 (carb) base motor
AFR 305cc cnc chamber heads
original 800 cfm Holley carb with minor blending
original Dart 6200 intake matched to the heads
original thunderbolt V ignition
small custom ground cam
Morel hydraulic roller lifters
Manley push rods
I spent a lot of hours on the phone and here on OSO talking with Bob Madara and working with Michael's racing most of the winter to come up with the right combo. With the help of Michael's Racing we had the motor set on the dyno pulled 620 HP on the first pull fine tuned the jetting and had it back in the truck by 2:30 in the afternoon.