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grumpyvette
09-20-2010, 09:22 AM
rockers and rocker studs rarely if ever break for no reason, theres almost always without exception, a clearance or geometry issue, thats the cause,it requires hundreds of lbs of force, to snap off a rocker stud, and thats almost always the result of a clearance issue like spring bind or rock slot to rocker stud clearance being too tight or the rocker/valve train geometry being wrong., just because some component rotates without binding up , does not mean its going to function at higher rpms and loads
if you have not verified all the clearance issues Id strongly suggest you look into that.

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=181

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1376

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=528

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1005

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=399

http://www.maxchevy.com/tech/2007/ii_12-stud-1.html

IM always amazed at the guys that think swapping from 3/8" to 7/16" rocker studs is going to be a huge improvement,in valve train stability,now theres not the slightest doubt that an increase of about 18% in cross sectional area on the studs a significant increase in strength, and while that helps, its not the huge improvement many people think it is because its generally not the rocker studs that fail from flexing,unless they are defective, as most would have you believe, but because its the rocker geometry and rocker support not the stud diameter, that matters, more, you can,t expect a rocker stud with one end unsupported to have any where near the resistance to deflection that a rocker stud with BOTH ends supported will have.
if you support both ends of the rocker studs you easily increase the load bearing capacity to far more than the additional stud diameter increase, can ever do,having one end unsupported the stud acts a bit like a nail being pulled by a hammer, in that loads applied to the upper end tend to both bend the nail and pull on the lower end thats where the use of STUD GIRDLES comes into play.
simply supporting the rocker stud tips so that the forces acting on a single rocker stud are now opposed by the resistance to deflection of all 8 rocker studs
is a huge improvement



http://www.summitracing.com/parts/SUM-141010/?rtype=10
http://static.summitracing.com/global/images/prod/large/sum-141010.jpg
http://www.summitracing.com/parts/CCA-4014/
http://static.summitracing.com/global/images/prod/large/caa-4014.jpg

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=1769

Poltergeist
09-20-2010, 09:45 AM
Great info. :cool2:

nowukno
09-20-2010, 12:42 PM
Great info. :cool2:
X's 2:cool2:

grumpyvette
11-06-2010, 11:46 AM
If you swap to a higher ratio rocker it changes the push rod geometry

http://forum.grumpysperformance.com/viewtopic.php?f=44&t=2839&p=7344&hilit=adjustable+guide#p7344

http://forum.grumpysperformance.com/viewtopic.php?f=52&t=126&hilit=louis+rocker
http://www.grumpysperformance.com/adjustablesbc.jpg

and you may need too use the correct adjustable guide plates when you find the push-rod alignment is in need of minor tweaking to get the clearance and geometry correct

http://www.maxchevy.com/tech/2007/ii_12-stud/full/STUD-12.jpg
http://www.grumpysperformance.com/louis1.jpg
http://www.grumpysperformance.com/louis.jpg

using a louis tool, this tool is a GUIDE /tool for use with a high quality DRILL,its made of HARDENED STEEL that FORCES the DRILL BIT to drill thru the head to correctly lengthen the pushrod slot for increased clearance, they usually come WITH INSTRUCTIONS AND THE NECESSARY DRILL