Did this already... not the issue.cardo0 wrote: ↑Tue Jul 10, 2018 12:48 pm The rocker arms need to be checked for clearance. Clearance of the stud and spring retainer. An unbent paper clip works for this if thick enough. Crane came tech info explains this. Most owners expect valvetrain parts are just bolt on and go and find the bad results later.
Broken Rocker Studs... Why?
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Re: Broken Rocker Studs... Why?
Re: Broken Rocker Studs... Why?
As a few of you have suggested, it really just seems like the studs are not up to the task of handling the increased spring pressure. I suppose this should not come as a huge surprise as many of these parts are supplied by the lowest bidder to GM. Hopefully a set of ARP's cures the issue.
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midnightbluS10
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Re: Broken Rocker Studs... Why?
AFAIK, 480-490 lift is max for Vortec heads without needed modifications like modifying the valve guide boss, etc... Just springs won't fix it, AFAIK. Was all of that done to the heads before this? If not, that's proba ly why you're breaking studs. Happens to a lot of people at that lift on stock vortecs with no supporting mods.
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bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
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mag2555
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Re: Broken Rocker Studs... Why?
340 open pressure, so your expecting a stock pressed in stud to hold up to some 60% greater load then stock!
I am surprised you have not snapped off more of them to be honest!
I don't know about you folks but with the average budget most folks have when I build them a motor I don't expect for example the Rods to have 60% reserve strength for the rpm I am shotting for!
I am surprised you have not snapped off more of them to be honest!
I don't know about you folks but with the average budget most folks have when I build them a motor I don't expect for example the Rods to have 60% reserve strength for the rpm I am shotting for!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: Broken Rocker Studs... Why?
midnightbluS10 wrote: ↑Wed Jul 11, 2018 5:48 am AFAIK, 480-490 lift is max for Vortec heads without needed modifications like modifying the valve guide boss, etc... Just springs won't fix it, AFAIK. Was all of that done to the heads before this? If not, that's proba ly why you're breaking studs. Happens to a lot of people at that lift on stock vortecs with no supporting mods.
The OP says he has .045" retainer to seal clearance. You can get away with .500" lift on stock vortecs using the comp 787-16 retainer with a beehive. I am using the same set-up with a .495"/.500" cam with less open spring load and ARP screw-in studs. Never touched the guide bosses on the vortecs.