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Registered User
Join Date: Jan 2012
Posts: 3
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valve springs
long time listener, first time caller, rebuilding 1980 sc 3.0 back to stock, I have a question on valve springs, purchased new set from pelican, and I am checking valve spring compression on install height, pressure obtained between 95-98, are these numbers in the ballpark for ft/lbs
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09-04-2013, 10:22 AM
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Registered
Join Date: May 2003
Posts: 3,346
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The data I have, which is second hand from the internet, says stock seat pressure is 75lbs. 95-98 sounds more like the pressure for a race spring set.
-Andy
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72 Carrera RS replica, Spec 911 racer |
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09-04-2013, 02:32 PM
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Schleprock
Join Date: Sep 2000
Location: Frankfort IL USA
Posts: 16,639
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Agree with Andy on the 90-something seat pressure at installed height. EBS Racing VMAX springs spec 94 lbs when using their Ti retainers and 98 lbs when using stock steel retainers
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Kevin L '86 Carrera "Larry" |
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09-04-2013, 02:55 PM
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Registered User
Join Date: Jan 2012
Posts: 3
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thanks for info, springs purchased at pelican #901-105-901-52-m260, not racer type, if seat pressure is to high will this cause problems with stock cams?
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09-04-2013, 06:19 PM
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Registered
Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,532
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Too much pressure wears the cam lobes.
Bruce |
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09-04-2013, 06:46 PM
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That's where engineering comes in...just enough pressur applied the the rocker so that it follows the cam profile at high RPM.
If the pressure is correct for the inertia of the valve/rocker/spring combo...and has a little excess to allow for slight over-rev...tehn it's the best it can be. This is why lighter valves and rockers can contribute so much to the longevity of an engine. Bob
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Bob Hutson |
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09-05-2013, 03:21 PM
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Harley
