Midvalley

got a motor build underway... and all down to cam selection..

gen 6 454 roller block
496 stroker
305 dart top end setup
looking at the 731 or 791.... crane roller for a nice 5200 RPM peak rpm setup

would the 114 lobe center be better with wet exhaust or do the if it aint broke dont fix it of the 731 setup that is a nice KISS setup for that size motor...

going into a 22 ft checkmate vision
had a 496 with 761 in it before some dousche stole the engine in a storage unit prior to my buying the boat and it was about perfect for the boat HP and use wise... but not looking to be as aggressive because area i can boat is MUCH SHORTER in distances


will be GIL manifolds and later when $$$ allows headers

or would it be more worth the $$$ to get a firing order swap grind of either of them

ULTIMATE RELIABILITY is goal. not over all peak tq and hp... and smoother idle for ease of slow speed in tight quarters is the goals


everything says 791 and the 114 lobe center is the winner but you never hear of anyone using it...

Mr Maine

What are the specs of the 791? I think with a 496 stroker the 741 would be better over the 731.

getrdunn

iTrader: (7)

Something he doesn't want. 246/254-680/680 114 lsa. Lol

Midvalley

that's not the 791.... the 791 is IDENTICAL to the 731 but cut on a 114 LSA

Cam Style: Hydraulic roller tappet Basic Operating RPM Range: 1,800-5,800

Intake Duration at 050 inch Lift: 226

Exhaust Duration at 050 inch Lift: 236

Duration at 050 inch Lift: 226 int./236 exh.

Advertised Intake Duration: 288

Advertised Exhaust Duration: 298

Advertised Duration: 288 int./298 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.587 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.610 in.

Valve Lift with Factory Rocker Arm Ratio: 0.587 int./0.610 exh.

Lobe Separation (degrees): 114

Computer-Controlled Compatible: Yes

Grind Number: HR-226/345-2S-14 IG


GETRDUNN you looked at the 691... WAY TO MUCH CAM for a 496 in a boat lol

Midvalley

3 cams smaller, minor change between it and 731

4 42
57 (1) valve opening vs
6 40
55 1 timings 109/119 spread vs 107/117

only change

SB

iTrader: (1)

731's and 741'shave been fine with stainless marine exhausts and Diamond Marine's KE's. on 454's -540's. I would not get Gill's unless the HP500 style tails that go way up before going back down.

getrdunn

iTrader: (7)

I'm confused. This must be it's angry twin brother.

Midvalley

168791 not 139791 gen 6 roller cam there getrdunn in a MK IV you would be basically looking at a 139771....

Midvalley

boat is set up for dry jacketed exhaust but may not immediately get it

SB

iTrader: (1)

So, your hot girlfriend isn't yet but your planning for it ?

Sorry, could resist, in a funny mood tonight.