articfriends

With the problems I started out with this season I DO need them,thanks Gary,Smitty

GPM

What wall thickness push rods are you running?

Elite Marine

I'm switching to them also.

The pushrod geometry of the Big Block is poor at best. Most guys running Dart heads have to modify the guide plates to prevent the pushrods from rubbing on them under no load, so under load there has to be a pushrod rubbing somewhere. I had (2) Crane Gold Rollers come off the push rods several years ago. And never want to see that happen again.

articfriends

.083 wall,the problem I had was on 3 seperate occasions the rocker nuts cracked below the adjuster hex and backed off allowing puchrod/lifter/guideplate damage. Everyone tells me I am tightening the nuts too tight BUT I have built at least 50 motors with adjustable rockers and I had one nut crack once 5 years ago on cheap imported harland sharp rockers. I never had a crane gold nut or even a mr gasket poly lock ever crack,seems strange that 3 nuts cracked within first 15 hours of running this motor (they were all comp pro-magnum nuts). Swapped them all to ARP nuts that were actually thinner where the cracks were occuring and haven't had a problem since. I am done with comp anything as there is a pattern of failure there. I am only running about 190 psi seat/450 open with hydraulic roller,less than 6000 rpm's and barely over .600 lift,Smitty

Vinny P

Smitty,
Would you happen to have the ARP Part # for those adjuster nuts? I am running Comp Pro Magnum rockers on my 540. I dont want to have the same problem as you did.

vinny

GPM

Smitty, I didn't have very good luck with Comp's springs or rockers, I like their solid roller cams.

articfriends

Arp part # 300-8245-they have the shank reduced to .550 to fit the comp rockers.49.95$ in the comp products catalog. If I knew these were available I would have bought them after the second nut cracked. The first nut cracked on dyno and didn't hurt anything (didn't even know it until afterwards). The second one cracked and backed off on lk michigan on sunday after SOTW,bent a pushrod,no other damage. The 3rd one broke on vacation on lk winni,wasted pushrod,lifter,guideplate. Spent second 1/2 of vacation watching boats from shore!! I tore motor down to lifters in the boat as soon as I got home,over night aired a lifter set,pushrod and assorted parts and had it running in time to watch the port huron races from the water 2 days later. Motor ran flawlessly for 9 weekends in a row after that other than one broken lower xr gearset and wasted bearings. I am planning on jesels for next year to prevent problems,Smitty

Vinny P

Thanks Smitty

KAAMA

That's what I always hear....the weakest link in a big block Chevy is the valve train. The old stud mount rocker arm system is an outdated design from the 1960's.....yes, it still works fine, but if you can afford to do it, the much better, more stable way to go is the shaft mount system either from Jesel or T&D....no pushrod guide plates, no studs to flex, no stud girdles needed.

Cam-shaft

083 wall,the problem I had was on 3 seperate occasions the rocker nuts cracked below the adjuster hex and backed off allowing puchrod/lifter/guideplate damage. Everyone tells me I am tightening the nuts too tight BUT I have built at least 50 motors with adjustable rockers and I had one nut crack once 5 years ago on cheap imported harland sharp rockers. I never had a crane gold nut or even a mr gasket poly lock ever crack,seems strange that 3 nuts cracked within first 15 hours of running this motor (they were all comp pro-magnum nuts). Swapped them all to ARP nuts that were actually thinner where the cracks were occuring and haven't had a problem since. I am done with comp anything as there is a pattern of failure there. I am only running about 190 psi seat/450 open with hydraulic roller,less than 6000 rpm's and barely over .600 lift,Smitty

Wow. sounds like a lot of spring psi for a hydraulic roller cam. 190 over the nose is more than I would like to see on a hydraulic roller cam that is running only 6000rpms. However, that is just me. Thanks Cam-shaft.