Issue with Comp #980 valvesprings?

[1KWIK6]

I measured 32 Comp #980 springs on a calibrated fixture today. Comp rates the seat pressure as 91# @ 1.700". However, I found that they ranged from 80-84# @ 1.700". I added the stock cups and found the pressures ranged from 94-96#.

Has anyone else measured these and found the pressures to be lower than advertised? I'm tempted to run them with the cups to get the pressure where I need it to be.

 

[bison]

I measured 32 Comp #980 springs on a calibrated fixture today. Comp rates the seat pressure as 91# @ 1.700". However, I found that they ranged from 80-84# @ 1.700". I added the stock cups and found the pressures ranged from 94-96#.

Has anyone else measured these and found the pressures to be lower than advertised? I'm tempted to run them with the cups to get the pressure where I need it to be.

Yes. Typically id shim till i was at 105lbs@1.7in. in most cases. Only time i wouldnt is if it was the stock cam.

 

[1KWIK6]

Thank you, Bison. What pressure would you shim them to for a stock cam? I was going to drop them in with the cups (~95# seat).

 

[bison]

Thank you, Bison. What pressure would you shim them to for a stock cam? I was going to drop them in with the cups (~95# seat).

thats fine

 

[87GN_70GS]

Be careful that any shims will increase the solid heigth