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Old 02-05-2012, 02:33 PM   #1
mannymen
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Default Maximum Valve Spring Pressure

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


Thanks
Manny
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Old 02-05-2012, 04:07 PM   #2
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Default Re: Maximum Valve Spring Pressure

They tend to pull out or break with the stock springs.
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Old 02-05-2012, 06:57 PM   #3
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Default 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?
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Old 02-05-2012, 07:31 PM   #4
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Default 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
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Old 02-05-2012, 08:52 PM   #5
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Default 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)
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Old 02-05-2012, 09:07 PM   #6
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Default 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
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Old 02-05-2012, 09:47 PM   #7
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Default Re: Maximum Valve Spring Pressure

i've had the studs "pinned" before, might be an alternative for ya...
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Old 02-05-2012, 11:13 PM   #8
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Default 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)
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Old 02-09-2012, 01:42 AM   #9
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Default Re: Maximum Valve Spring Pressure

Quote:
Originally Posted by Tom keedle View Post
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
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Old 02-09-2012, 11:53 AM   #10
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Default Re: Maximum Valve Spring Pressure

Quote:
Originally Posted by trmnatr View Post
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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