Sheared Rocker Stud
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Instructor
Joined: Nov 2010
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Sheared Rocker Stud
I sheared a 3/8" Edelbrock Rocker Stud after a decent 2nd gear pull. The stud sheared off right at the top of the rocker/bottom of the poly-lock. Rocker looks ok, valve keeper looks ok, pushrod rolls smooth on glass. Everything seems ok except for the broken stud and a hole in the valve cover. Anything in particular I should be checking? Already checked for coil spring bind, double checked the alignment, etc. At this point I'm going to slap ARP 3/8" studs into it, a new valve cover, and then call it fixed. Any insight/experience greatly appreciated--captainkawasaki
Racer
Joined: Oct 2011
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From: Benching 455RAW Texas
http://www.google.com/url?sa=t&rct=j...A3mxZA2xXUZNqw
Couple posts on other sites but nothing like Proform rocker failures. Stock cam and lifters?
Couple posts on other sites but nothing like Proform rocker failures. Stock cam and lifters?
Thread Starter
Instructor
Joined: Nov 2010
Posts: 172
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Crane gold race roller rockers, comp cams something or other mild cam (around .550 max lift) so nothing too wild or cheap. The stud was an edelbrock 3/8 job. After disassembly My best guess is that I over tightened the poly lock. I had one poly lock come loose so I went through with a 5/8 socket and gave all the rocker nuts another quarter turn or so. I later read that is a big no-no and it can split the tops of the rocker studs when they get hot. ARP studs are on the way, i'm going to replace them all just in case I screwed up another one.
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Instructor
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Safety Car
Joined: Nov 2009
Posts: 3,971
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From: Adelaide South Australia
.550 lift with full roller rockers, 3/8 stud, lots of rpm and a standard rocker cover = what just happened to you !
if you have seen footage of inside a rocker cover at rpm you will be surprised who much everything moves around, even the studs lean backwards and forwards like a tree in the wind, thats why people use stud girdles and/or 7/16 rockers, and tall rocker covers.
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Thread Starter
Instructor
Joined: Nov 2010
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.550 lift with full roller rockers, 3/8 stud, lots of rpm and a standard rocker cover = what just happened to you !
if you have seen footage of inside a rocker cover at rpm you will be surprised who much everything moves around, even the studs lean backwards and forwards like a tree in the wind, thats why people use stud girdles and/or 7/16 rockers, and tall rocker covers.
Thread Starter
Instructor
Joined: Nov 2010
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It's hard to see in the picture but the mount for the tach filter (the brown thing with the white wire coming out of each end) was coiled up by the hunk of stud and valve cover that came out. It also launched the emblem out under the car. I heard the pieces jingling down the road. I walked the section of road three times but all I found was half of the missing valve cover, the emblem, stud, and rest of the valve cover are all missing in action.
Safety Car
Joined: Nov 2009
Posts: 3,971
Likes: 341
From: Adelaide South Australia
you will need taller rocker covers too, mine are 3.5" and my stud girdle wont fit until i grind off the breather covers inside of them (which are just small pieces of alloy spot welded in so the breathers dont get oil going up them.
p.s. on the bit of cover that broke off is there any scrape marks on the underside of it ?
Last edited by blackozvet; Jun 12, 2014 at 03:28 AM.
Melting Slicks
Joined: Oct 2000
Posts: 2,158
Likes: 9
From: N.E. WA
Moroso had centerbolt stud girdles but they seem to be discountinued. #67040 and their valve covers that fit are $500. I've seen some modified girdles as well, just google them.
I have a valve cover. I bead blasted it and it kinda screwed it up. It looks like there was pockets in the casting or something. It's not terrible but not show quality. You could fill the small pockets and then paint. I think I still have the emblem as well. Let me know.
I have a valve cover. I bead blasted it and it kinda screwed it up. It looks like there was pockets in the casting or something. It's not terrible but not show quality. You could fill the small pockets and then paint. I think I still have the emblem as well. Let me know.
Thread Starter
Instructor
Joined: Nov 2010
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yes you will need taller rocker nuts, you usually get them when you buy a stud girdle,
you will need taller rocker covers too, mine are 3.5" and my stud girdle wont fit until i grind off the breather covers inside of them (which are just small pieces of alloy spot welded in so the breathers dont get oil going up them.
p.s. on the bit of cover that broke off is there any scrape marks on the underside of it ?
you will need taller rocker covers too, mine are 3.5" and my stud girdle wont fit until i grind off the breather covers inside of them (which are just small pieces of alloy spot welded in so the breathers dont get oil going up them.
p.s. on the bit of cover that broke off is there any scrape marks on the underside of it ?
Thread Starter
Instructor
Joined: Nov 2010
Posts: 172
Likes: 0
Moroso had centerbolt stud girdles but they seem to be discountinued. #67040 and their valve covers that fit are $500. I've seen some modified girdles as well, just google them.
I have a valve cover. I bead blasted it and it kinda screwed it up. It looks like there was pockets in the casting or something. It's not terrible but not show quality. You could fill the small pockets and then paint. I think I still have the emblem as well. Let me know.
I have a valve cover. I bead blasted it and it kinda screwed it up. It looks like there was pockets in the casting or something. It's not terrible but not show quality. You could fill the small pockets and then paint. I think I still have the emblem as well. Let me know.
Pro
Joined: Apr 2001
Posts: 744
Likes: 13
From: Lenoir City TN
I sheared a 3/8" Edelbrock Rocker Stud after a decent 2nd gear pull. The stud sheared off right at the top of the rocker/bottom of the poly-lock. Rocker looks ok, valve keeper looks ok, pushrod rolls smooth on glass. Everything seems ok except for the broken stud and a hole in the valve cover. Anything in particular I should be checking? Already checked for coil spring bind, double checked the alignment, etc. At this point I'm going to slap ARP 3/8" studs into it, a new valve cover, and then call it fixed. Any insight/experience greatly appreciated--captainkawasaki
Hope this helps!
Race Director
Joined: Apr 2003
Posts: 17,698
Likes: 1,667
From: moraga ca
Reading this thread, there is no way the op would need a stud girdle with a .550 lift cam. If everything is right, a 3/8" rocker stud should be sufficient. A 7/16" stud will be pretty much bulletproof with that cam. A stud girdle would be way overkill.
Safety Car
Joined: Nov 2009
Posts: 3,971
Likes: 341
From: Adelaide South Australia
Im pretty sure he does need a taller cover,
if you look at the photo with the hole in it, the rocker looks pretty dam close to that cover, or maybe thicker gaskets (like the blue ones) at least to get some clearance ?