Donman

What cam would you run in this engine?

Gen VI 454, bored .030", 4.25" stroke, 6.385" rod, (489 cubic inches ), 10.0 : 1 compression, Merlin VR square-port heads, Strip Dominator intake, 800 Holley DP, full MSD ignition, Stainless Marine Gen III exhaust. This runs a factory style roller. I am currently running a Crane 731. I have the engine apart right now and would like to bump it up. I was running 8.5 compression, but bought new pistons. Reversion is not an issue, the exhaust is dry up to the tip.
Should I keep my current cam?
What do you guys suggest?

I can have a custom-grind made also....

rmbuilder

HigherPower,
Where will you prop for peak power/max WOT? Target HP?
Bob

Donman

I would like to see my MAX rpm at about 5800.

I would like to get about 550 hp out of this combination.

Thank you for your response. The MAIN reason I am a member here is because of the excellent technical discussion.

rmbuilder

Higherpower,
Those heads have very strong low/mid lift flow characteristics. The runner size/CSA will also provide good velocity for this displacement. Your target of 550 HP brings you in @ 1.13 HP/CID which would be no problem with a cam change. I would closely watch timing and octane and determine the exact compression ratio with the new components.
Bob

Donman

So...... what kind of specs do you suggest?
Can you grind one?

Pat McPherson

Crane 741 or Custom Grind...

Hey you want to sell that 731? If so PM me the $$...

Donman

Yes Pat, I will be selling it as soon as I have replacement in hand.

Prowler

the new 741 falls off at 5500 rpm's now and the 731 falls off at 5200 rpm's trust me i know.so now it's time for another cam change.

Pat McPherson

741 only to 5500? in a 454 or 502?

Yes, I would agree that the 731 is good to about 5200 in a 502...

Donman

Agreed, the dyno does not lie. 5200 is where power starts falling with the 731 cam.