Join Date: Jul 2001
Location: Tampere, Finland
Question about valve spring installed height?
I think the reason for so many different installed heights is that there arent one simple correct installed height.There are so many variables in valvetrain construction that it is impossible just list one correct.
I found the Tavia spring tester very handy, available for around 60 bucks from Summit.
If you increase the installed height it reduces the closed and open pressures.How much; depends on spring itself.The closed value may be correct with the new increased height but the open value not.
What I found when assembling my heads this winter was that even though the manufacturer´s advertised installed height did not match the situation at the heads, the springs still had the advertised values.
Just make sure there will a total of 0.060" between max valve lift and coil bind.
Here the Tavia mini Tester comes on handy:
install the tester and the spring in a vice, adjust the spring height to max valve lift and record the spring pressure and the height.Then, tighten up the vice until the pressure skyrockets and record the spring height.The difference between these two values is your safety margin.If it is more than 0.060" you are safe.
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