737jetmech

iTrader: (1)

Anyone running the crane hyd roller 139651 cam ? Its the next step from the 741 grind . I have a pair of 496 ( 1/4 stroke ) mark4 block 454's currently running a very conservative 731 grind .Engines have dynoed @ 785 hp ( 5 psi ) after intercoolers .Static compression 9 to 1 . I have them out for overhaul and considering running a more aggressive profile cam . www.cranecams.com is the 651 to much for these engines ? I run K/E's dry ... so reversion shouldn't be a factor .
I know the 741 will be a improvement over the 731 ... but have been leaning towards the slightly more aggressive 651 grind.

What do you guys think ?

blue thunder

I think your heads won't flow enough to support much more than the 741 and will hold you back from the higher lift cams. You might consider a longer duration cam or even get your cams reground to compliment your heads and setup. Bob Madra of marine kinetics would be a great source for info on your specific setup and if regrind is an option. Have a nice day and good luck with your project. Let us know what you decide to do.

737jetmech

iTrader: (1)

Thanks Dave . Regrinding my cams is not an option . I want an off the shelf stick . My heads have surprised the experts there one of a kind for sure . 290 Edelbrock Oval port matched to the rectangular blower intakes. Only way to see is to flow em on the bench . Then again ... how important is the port size when were talking a 496 inch engine ? We can speculate all day ... on cams ... just wanted to throw it out there to see if anybody has run this cam and what were the results ? Franks buddy had the 651's in this N/A 502's with iron heads ... 9 to 1 comp ... they really woke them up ... he did turn them to 6000 rpm .

blue thunder

I don't think your changes to the heads would impact your flow numbers of the heads unless you did more to them then the pics showed. I also am not familiar with the edelbrock oval port flow numbers so I can't say for sure. I am familiar with the rect port edelbrock heads flow numbers and they are about done at .600 of lift if memory serves me. So just make sure your heads can support the 651 and I think you have a winner. I am just concerned they cannot. Franks example was with a guy running iron rectangle I think.

bunky1957

I put together a 548" motor for my street car. Used a 731 cam first and it was too mild. Replaced it with a 741 and it really woke up the motor,it would pull about 500 rpm higher than the 731.

mike tkach

iTrader: (3)

i have them in my 548 in motors in my cat,i love them,i have 8.71s with innercooler,made 950 at 6500 with 8 lbs boost,i used the isky tool room springs,set at 185 seat pressure.im not sure how it will work with your oval port setup.give it a try,you might be pleasantly suprised.

mike tkach

iTrader: (3)

i forgot to mention,i have dart 320 heads that have a mild port job.

Griff

IMO, the 651 has way too much duration for a 496ci. You would have to spin it at least 6000rpms to make power. I think the 741 would be a better choice.

offshoredrillin

741 is the same cam in a 525 correct?

Noise Pollution

Dyno Sheet for Bob's motor with blower. Sorry for the quality. Couldn't find originall sheet.
Peak torque - 773 @ 4500
Peak Hp - 785 @ 5800