Valve spring pressure and a Stipe cam

[Jim Brierley]

I've also used Isky springs on performance cams. They are very good but shorter so require a spacer of approx. .500", making them more difficult to install.

 

[hardtimes]

We may want to ask Don Snyder the source of the springs he sells. The Hardware Products site has another spring that has the same specs as the standard Model A spring. It's PN is 14078. I guess we could put that fatigue question to the Hardware Products people.

Fatigue of a spring is important and hard use will bring out fatigue in sub-standard spring material used.
In a stock A engine, with the light seat pressure originally used there, most any old A spring with correct measurements will run such engine at low rpm, likely forever.
However, we expect more out of model A/B engines these days when they are warmed up / 'improved', so use the best valve spring that can be had, is my view and practice. New old stock LZ springs are excellent , as are Isky valve springs, in my experience. Nos flathead V8 springs have also proved consistent when checked for height/pressure, etc....