451 life expectancy?

[dartmeister]

Has anyone here built a 451 that has seen a bunch of street miles or alot of seasons of severe duty use at the strip? I'm thinking about putting one of these together and it would put me more at ease if I know that this is a reliable combination. See Ya

[DartGT66]

I built a 451 six years ago, it has maybe 10 000 street miles and has seen a lot of 7000+ rpm punishment. It's still OK and we have had no problems with the short block. It's got a 440 forged crank with turned down mains, Eagle rods and ROSS off the shelf 4.375" flat top pistons. It makes propably a little over 500 hp.

[montrose ram]

DART- Curious as to what kind of cam you're running. Thats alot of 'Rs' for a street driven big block! I'm runnning a Hughes 5056 and was thinking maybe I could go a little bigger. Was thinking about the Ultradyne .640 lift. What do you think? dartmiester may also need advice on cam selection that will live on street.

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[DartGT66]

I'm running a Cam Motion roller at the moment, have tried a couple of different grinds and this one seems to work pretty well. It's got 276/282 degrees at .050" and .67"/.61" lift with 111 degree lobe separation angle, and it's advanced 4 degrees.

[dartmeister]

Thanks for the reply dartgt66, sounds like she's holdin' up just fine! See Ya

[JANDJ]

Originally posted by dartmeister:
Has anyone here built a 451 that has seen a bunch of street miles or alot of seasons of severe duty use at the strip? I'm thinking about putting one of these together and it would put me more at ease if I know that this is a reliable combination. See Ya

I AM CURENTLY RUNNING A 431(4.280 BORE 3.75 STROKE)WHICH IS THE SAME AS A 451 COMBO JUST IN A 383 BLOCK.I HAVE 300 PASSES AT 6500 RPM AND ITS STILL TOGETHER WITH LITTLE TO NO PROBLEMS.HOPFULLY IT WILL STAY THAT WAY. GOOD LUCK WITH YOURS BUT I HAVE HEARD NOTHING BUT GOOD THINGS ABOUT THE 451 IN FACT I THINK IT IS A LITTLE BETTER THAN A 440 BECAUSE THE BLOCK IS A LITTLE MORE RIGID BEING A LOW DECK.

[montrose ram]

DART_That cam looks pretty trick! Is there any secret to running a roller that big on the street? I read where Freiburger said he had to pre-oil his Hemi if it sat for more than a couple of days! That dosen't sound like much fun!

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[451Mopar]

My 451 only has a few thousand miles on it, but the short block seems to be holding up great. Here is an intresting fact:
The Ross pistons for the 451 are over 4 pounds lighter (per set) than the Keith Black pistons.

I have worried about the aluminum roller rockers and valve spring life on my 451, but they seem to be holding up fine also.
I am running a mild 251 duration @ 0.050" Ultradyne roller cam with 0.620" lift with my 1.6:1 rocker arms.
Hughes sells a max velocity solid cam with simular specs and uses it in their 570 HP 451 stroker engine.

[DartGT66]

No, i think this particular cam has pretty 'soft' ramps since I have used the same valve springs for four years. When at the races, all the other racers measure their spring pressures between the rounds and all I do is push the dipstick pack down. I think same kind of performance could be obtained with a flat tappet, but after wiping out a couple of sticks I got fed up and switched to a roller. My first roller was a Comp Cams 308R which is pretty tame. The car felt stronger in the top end with the MP 296/.557" but never got to track with it. With a custom grind 262/.530" mechanical cam the car run 12.16/116 mph with regular 205/75/14 whitewall radials. With the roller and otherwise the same set up except 245/60/14 M&H's the car run 12.20/115 mph at best. The roller swap cost about 1000$ (cam, lifters, springs, locks, retainers, pushrods, cam button) and performance wise in a moderate vehicle I think it was not worth it. But since I had wiped three cams in a short period of time, I had already 450$ in the cams and didn't want that trend to continue. All the wiped cams were 296/.557" cams, the custom grind I swapped in with used, not numbered lifters every time the cam went south survived. I was told by McCandless that the reason for the cam problem was propably the quality of the MP cam and the MP springs.

[JANDJ]

YOU WENT THROUGH THREE BUMP STICKS, THAT MUST HAVE JUST PI***D YOU OFF.I HAVE A FRIEND THAT FLATTENED TWO HUGHS CAMS IN A 512 INCH MOTOR THAT HUGHS BUILT FOR HIM.NEEDLESSLY TO SAY HE IS PREECHING EVERYWHERE THAT HE GOES ABOUT DAVE HUGHS ENGINES. HE WAS TOLD THAT THE LIFTERS WERE NOT HARDENED PROPERLY,THE LIFTERS HAD HOLES IN THE BOTTOM OF THEM AND THE CAM WASNOT THAT WORN.HE ALSO WAS TOLD THAT HUGHS USES "WHITE BOX " LIFTERS.I FORGOT TO MENTION THAT THIS WAS A HYD.CAM.