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mannymen 02-05-2012 02:33 PM

Maximum Valve Spring Pressure
 
What is the safest / maximum spring pressure one can run in a SBC with press-in studs?


Thanks
Manny

Paul Precht 02-05-2012 04:07 PM

Re: Maximum Valve Spring Pressure
 
They tend to pull out or break with the stock springs.

mannymen 02-05-2012 06:57 PM

Re: Maximum Valve Spring Pressure
 
"They tend to pull out or break with the stock springs"

Under what kind of conditions does this occur in?

above or under 6500?
over 300 lbs open pressure?

tj310 02-05-2012 07:31 PM

Re: Maximum Valve Spring Pressure
 
Problems occur with stock rocker arms if they pinch the stud at full lift, shorter pushrods may help, we used to run stock Z28 springs.---Trevor

mannymen 02-05-2012 08:52 PM

Re: Maximum Valve Spring Pressure
 
Paul,

Thanks for the info. My plans are to use a set of stock 441 heads 1.94 - 1.50 (press in stud) with z28 springs and aftermarket roller tip or full roller rockers. For some limited street time and some bracket racing.

The camshaft will be in the ballpark of

327 / 350 hp cam

or something similar below

Camshaft Lift: .450 Intake /.460 Exhaust
Flat Tappet Duration @ .050" (222°Int/222° Exh)

Paul Precht 02-05-2012 09:07 PM

Re: Maximum Valve Spring Pressure
 
Some heads might be fine but there is an inconsistency from head to head and stud to stud. If the heads have a good history a slight step up from stock should be OK

Tom keedle 02-05-2012 09:47 PM

Re: Maximum Valve Spring Pressure
 
i've had the studs "pinned" before, might be an alternative for ya...

rustbucket79 02-05-2012 11:13 PM

Re: Maximum Valve Spring Pressure
 
You're not going to break studs with that cam/spring combination, and you shouldn't be pulling studs either. If you want a guarantee, drill the stud bosses with a 1/8" bit and install hardened roll pins, or have a shop pull the studs and tap them for repair studs. (shoulderless studs)

trmnatr 02-09-2012 01:42 AM

Re: Maximum Valve Spring Pressure
 
Quote:

Originally Posted by Tom keedle (Post 307888)
i've had the studs "pinned" before, might be an alternative for ya...

All studs should be pinned or screw in studs and guide plates

Harry 6674 02-09-2012 11:53 AM

Re: Maximum Valve Spring Pressure
 
Quote:

Originally Posted by trmnatr (Post 308517)
All studs should be pinned or screw in studs and guide plates

The cost is cheap compared to popping off a retainer. I found that out a long time ago.


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