Rocker studs breaking.....
06-14-2006, 09:29 PM
#1
Race Director
Thread Starter
Rocker studs breaking.....
Just wondering whether anyone had this problem before and why?
I just replaced another broken intake rocker stud last night
....the third in less than 2000 miles. (2 intake and 1 exhaust)
Dart Pro 1 heads, solid roller with Dart stud girdles.
Is there a specific way to tighten those girdles or did I just happen onto a bad batch of studs??
I just replaced another broken intake rocker stud last night
....the third in less than 2000 miles. (2 intake and 1 exhaust)
Dart Pro 1 heads, solid roller with Dart stud girdles.
Is there a specific way to tighten those girdles or did I just happen onto a bad batch of studs??
06-14-2006, 10:29 PM
#2
Race Director
I wouldn't run the motor again until you find out why you are breaking studs.
They break because they are overstressed and seeing you have a stud girdle on there and they still break I would assume something is way out of whack in your valve train.
Have you checked all the things you are supposed to check with regard to valve train geometry when you assembled the motor ?
They break because they are overstressed and seeing you have a stud girdle on there and they still break I would assume something is way out of whack in your valve train.
Have you checked all the things you are supposed to check with regard to valve train geometry when you assembled the motor ?
06-14-2006, 10:47 PM
#3
Race Director
Thread Starter
Originally Posted by MotorHead
Have you checked all the things you are supposed to check with regard to valve train geometry when you assembled the motor ?
The only thing I can come up with is that the studs that came with the heads are cheap parts. They sell cheap Dart Pro 1 heads because they put junk on them.
I replaced the broken studs (no name on them) with ARP studs. The replaced ARP studs have not broken but the other crap keeps breaking.
I just bought another set of ARP studs online tonight as I only had 5 left in my package of 8 and I replaced all the intake studs with them.
I don't understand unless the girdles are off somehow or the studs are cheap junk.
How much movement are on those studs after all ....
06-14-2006, 11:01 PM
#4
Burning Brakes
I had that happen to me a few times,if there Dart I would think they would use ARP studs,and if they aren't change them all to ARP .
The way to tell the cheap ones are too look at the top of the stud and see if it has a dimple on it, those are the
cheap ones ,
ARP are smooth and say Arp on the top,
Some may say I had wrong geomtry.
I kept braking one at a time every other week, after replacing the second I changed them all ,No more problems,
Some head companys cheap out on some parts Edel use too have cheapys but they have changed and use ARP.
The way to tell the cheap ones are too look at the top of the stud and see if it has a dimple on it, those are the
cheap ones ,
ARP are smooth and say Arp on the top,
Some may say I had wrong geomtry.
I kept braking one at a time every other week, after replacing the second I changed them all ,No more problems,
Some head companys cheap out on some parts Edel use too have cheapys but they have changed and use ARP.
06-14-2006, 11:22 PM
#5
Race Director
Well quite possibly they are cheap Chinese studs that are brittle. I would change them all to ARP, if you break an ARP there are some serious problems there. 
06-14-2006, 11:43 PM
#6
Le Mans Master
Member Since: Sep 2001
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Better check to see if all the studs are in-line with the others ... pull all rockers off & lay a straightedge across the entire row. If they are not in-line and you try & squeeze them into alignment with a girdle ... that is definately stressing them. Dunno where you got your heads ... but alotta places get Dart bare castings & finish the machinework themselves ... of course even Dart ain't above making mistakes either.
