[car4jim]

OK guys, Back to possible reasons why my FE Edelbrock head inner valve springs were failing. I have removed the engine and have more valve-train data for evaluation. Each valve has Dual Springs: Here is data I measured for springs installed in my engine:

Large Spring (Uninstalled Physical Measurements)
O.D Inches 1.51
Wire Dia. Inches 0.196
I.D. Inches 1.118
Height (no Load) Inches 2.42

Small Spring (Uninstalled Physical Measurements)
O.D Inches 1.1
Wire Dia. Inches 0.156
I.D. Inches 0.788
Height (no Load) Inches 1.94

I measured the actual valve stroke on the engine using a dial indicator & calipers and determined the following:
Assembled heights (bottom of spring to top of spring): 1.93-1.94”
Valve stroke (dial indicator on spring retainer): Intake: 0.437, Exhaust: 0.424.
Therefore : Spring height with valve full open:
Intake: 1.935-0.437= 1.498”
Exhaust: 1.935-0.424= 1.510”
Coil Bind (Engine Build data) 0.825. I inspected springs at full stroke and visually confirmed the springs are not close to coil bind.
Spring Pressures Engine shop data from spec sheet):
385 lbs @ 0.500
415 lbs @ 0.550
435 lbs @ 0.600
445 lbs @ 0.620
460 lbs @ 0.650
Using some curve fitting data and calculations, the spring force at compressed spring height of 1.51” is 448 lbs spring return force (approx).

Is 450 lbs a lot? Anything striking?