Shim or stretch valve springs

GoFastHP

New member
Shimmed yes, stretched no. Stretching will yield absolutely nothing as the spring will return to its original, or weaker, rating once being ran.

-Shannon
 

Ryan Thompson

New member
Both methods are illegal for/in BSP.
I think he means the valve seal by "shim" which is legal on the exhaust valve.

Shimmed yes, stretched no. Stretching will yield absolutely nothing as the spring will return to its original, or weaker, rating once being ran.

-Shannon
Agreed^

Stretching is a waste of time..you'll see a change and then it snaps right back. You need to buy a few sets of valves, and retainers...start measuring and swapping valves/retainers and this will get your installed height where you want it..that's for the shimming part of the questin..but stretching part is for pressure..and if you are having a pressure issue or not meeting the 10.8 rule then buy some more springs or different type as streching won't help.
 

gregp07

Member
Yep..a couple years back before there was an .815 , when the rule was only 10.8 @ .850 I shimmed mine..modified 5/8 flat washer=.060..too bad the springs weren't as good then as they are now.
 
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