North American Turbocoupe Organization



Valve Spring Question
Anthony M Offline
Member
#1
I've been looking around at v/springs and according to This Chart stock 88 T-Coupe springs (VS-1459) only have 33 lbs closed seat pressure...Isn't that awfully low?
I want springs that will be able to hold to a roller cam if/when I decide to swap. Soo, I looked up springs for a 91 Ranger. The same springs are listed, but also listed is PN 212-1243 and according to This Chart those springs have 79 lbs closed seat pressure.

My question is what is the Maximum pressure you would put on a slider cam? This is my daily driver BTW....

Thanks!
88 TC, T3, Volvo IC
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Pete D Offline
Administrator
#2
Actually the 1988 Service manual, for the 2.3 turbo, list the pressure specs as 71.3 to 78.7 @1.52" (closed) and 151.9 to 165.9 @1.12" (open). The 2.3 na springs are only slightly lower pressure, much higher than the 33 you got from chart #1.

The main things that govern how much spring pressure is needed are the valve train mass, valve lift and rpm. Pressures exceeding what is need to satisfy those criteria just result in excess wear on parts that include cam lobes and followers (slider cam) and valve faces and valve seats.

The stock springs are good for over 6000 rpm until they get weak and that won't happen for over 100K in most cases

The point I'm trying to make is you do not need higher pressure springs unless you are going with a high lift cam or are going to exceed the rev limited rpms on an ongoing basis.
Pete Dunham


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Anthony M Offline
Member
#3
Thanks Pete. I thought that 33 lbs closed looked way too low, even for stock.

All I am looking for is a decent set of stock replacements...At a good price of course [Image: biggrin.gif]

Hopefully the 170K mile v/springs is what's killing my top end power.

[This message has been edited by Anthony M (edited 05-13-2004).]
88 TC, T3, Volvo IC
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dezridin2 Offline
Member
#4
go to COMP cams web site....They got it all
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martin0660 Offline
Posting Freak
#5
I just got a set of Sealed Power stock replacements from rockauto.com for $26.00 for the set.

Bob Myers
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Pete D Offline
Administrator
#6
I use stock replacements from NAPA. I want to say around $30, maybe less.

[This message has been edited by Pete D (edited 05-13-2004).]
Pete Dunham


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Anthony M Offline
Member
#7
I just ordered stock replacements at Carquest for $2.89 a piece. And to think the dealership quoted me at 26 bux...a piece!

Im goin there tomorrow to pick them up.

Thanx all!
88 TC, T3, Volvo IC
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