Please keep in mind these engines are being dyno'd in complete marine trim, running stock manifolds with full water.Just for grins I pulled the serpentine belt and made a pull without accessories. That brought it up over 425 HP. If you installed dyno headers you easily pick up 25-30 HP. So for comparison purposes with other custom builds and dyno tests these engines are well over 450 HP. Also, for real world comparison, a 496 HO makes 430 HP on my dyno in complete marine trim, 496 Mag makes around 390 and 502 Mag made 440.

Bob Lloyd
Full Throttle Marine

Yes, I installed some take off 454 oil coolers I had.

Catpain Yarrr ,, bob ,, were the heads stock cast or some port work done and are you running stock size valves? How did the tq look with the bigger throttle body ? Hey Captain Yarrr what prop are you running ?

I did a pretty thorough bowl blend but used stock valves. Throttle body picked up about 10 ft. lbs. across the board. When I get time I'll try to post the dyno sheets if it's OK with the Capt. One other note. This is a 9:1 compression engine so it can run on 87 octane. That was one of the build requirements.

Nice project! Which heads and valve size?

Jeff

Stock Vortec heads & valves. Machined them for comp 986 springs.

hey bob, can you share cam specs,,,,, just curious ,,,

That's a pretty good result. Where did the torque end up?

Jeff

Sure Bob, feel free to post the sheets. Hopefully they can help someone.

Cam:
112.2 LSA
5.3 valve overlap
225.6 intake duration
.540 lift

Exhaust
232.4 duration
.526 lift

We are talking about spinning the props inward. Anyone know how the Dominator hull behaves with that?