I wanted to run my current valvetrain by you guys so that I could get some opinions. I just got my car up and running after about a years worth of work. I went out of town to my buddies house to start the tuning process and ended up breaking a rocker stud. We are trying to figure out the issue, so I wanted to run it by some people that might have had a similar situation happen to them.


1995 LT1
CC503 Cam
CC Pro Mag 1.6 Rockers
CC 26928 Beehive Valve Springs
CC 4705-16 Spring Seats
CC 614-16 Locks
CC 795-16 Retainers
CC Magnum chromoly 7.2 pushrods
TrickFlow Guideplates

Stock heads, never been re-surfaced.


When we pulled the valve cover, one of the rocker studs was snapped in half. It was a clean break. I had bought the studs barely used and thought they were ARP, but there was no stamp from ARP on the stud.

We believe that the springs may be too much for the 503 cam by creating too much spring pressure. Either that or it was just a freak accident and just needs new ARP studs. What do you guys think?? Any help would be greatly appreciated.

 

the 928's should not have snapped an ARP stud, unless you've got some serious valve train geometry issues.

 

The studs that I put in the car are not ARP. When I had them put in, I thought they were ARP. When we pulled out the broken stud, there was no stamp from ARP anywhere on the stud. I think that the studs are basic Comp Cams rocker studs.

 

And what do you mean serious geometry issues? What could be messed up enough to cause this?

 

What's the spec on the 26928 spring? I could not find it anywere.

Unless that spring has serious open pressure I'm not sure what happened
other than a bad stud. What spring locators are you using?

 

is it a 3/8" stud?

just get a GOOD set of ARP, not the el cheapo ones.....

they will hold that with no problem at all.

 

The rockers and studs are 7/16. This is why I am so confused here...I went with the absolute best parts I could afford and it still broke.

Locaters are the CC 4705.

 

Some info I found on a different site :

Quick Summary
Product: • COMP Cams® H/L Beehive™ Valve Springs For GM Gen III/LS Engines
Part Number: • #26928-16 (Set of 16 springs)
• #26928-1 (Single spring)
Features and Benefits: • .650” max lift, 125 lbs seat pressure at 1.800” installed height - for GM Gen III/LS engines
• Engineered specifically for use in severe-service street/strip & competition engines
• Designed for use in both hydraulic roller and solid roller camshaft applications
• Contains manufacturing processes normally only found in exotic race valve springs, which deliver an unmatched level of durability

 

I run a ARP stud with 260# seat pressure.......


I did break a stud before but it was not an ARP.

 

It is starting to sound like everything is set up just fine. I think I will just replace the studs with ARP and be done with it. I really didn't want to take a step down and replace the springs with the Crane double springs.

These are the studs that I should be running correct?
http://store.summitracing.com/partde...5&autoview=sku

 

While I am there, I might as well upgrade the adjusters to ARP. Are these the correct ones?
http://store.summitracing.com/partde...5&autoview=sku

 

http://store.summitracing.com/partde...5&autoview=sku

get the pro series

 

It seems to be getting harder and harder to trust anyone these days. People want to pawn their garbage off to others because of their own stupidity and they will say anything to get rid of it, unfortunately

 

And then there are those who condemn products that they have never used themselves.

 

meaning?