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How much will valve spring dampers add to seat pressure #3000575
01/01/22 11:20 AM
01/01/22 11:20 AM
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ragtop Offline OP
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How much lbs of seat pressure will stock dampers add to stock small block single springs? Thank you.

Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3000581
01/01/22 11:43 AM
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very little.

Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3000588
01/01/22 12:10 PM
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Originally Posted by ragtop
How much lbs of seat pressure will stock dampers add to stock small block single springs? Thank you.


Most have no effect on seat pressures, just off seat. It’s for harmonics, not pressure.

Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3000596
01/01/22 12:34 PM
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The reason I ask is because I am trying to get an aftermarket spring as close to the specs of the factory 340 spring, but the factory springs are rated without the damper and the aftermarket springs are rated with the damper. So if I can get an approx pressure at any seat height that the damper adds, I can more accurately compare the different aftermarket springs to the factory spring.

Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3000598
01/01/22 12:39 PM
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Originally Posted by ragtop
The reason I ask is because I am trying to get an aftermarket spring as close to the specs of the factory 340 spring, but the factory springs are rated without the damper and the aftermarket springs are rated with the damper. So if I can get an approx pressure at any seat height that the damper adds, I can more accurately compare the different aftermarket springs to the factory spring.




I’m thinking the 60’s and early 70’s manuals called out the added rate of just the damper.

For some reason between 5 and 10 lbs. comes to mind.

Re: How much will valve spring dampers add to seat pressure [Re: A727Tflite] #3000621
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i can't imagine a dampner adding 5lbs but maybe it's possible. that flat spring is for harmonics; not to be a pressure adder.

Re: How much will valve spring dampers add to seat pressure [Re: lewtot184] #3000640
01/01/22 02:27 PM
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I just looked in the '69 parts book and service manual and the only engine I could find with a damper was the Hemi. And the specification listed in the service manual was less damper.


"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3000696
01/01/22 04:14 PM
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Does it really matter? No one can see it and no one is going to measure the pressure. Just get an appropriate spring for your cam.


In theory, there is no difference between theory and practice. In practice, there is.
Re: How much will valve spring dampers add to seat pressure [Re: GomangoCuda] #3000713
01/01/22 04:51 PM
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All the aftermarket springs that use them include the damper in the rates.

Again, the seat pressure is not affected by the damper.

I looked through all my papers and can’t find the damper rate in the AMA papers, so I grabbed a stock max wedge spring from back in the day.

On my scale accurate to a gram it shows 6.9# just before bind.


Last edited by Transman; 01/01/22 05:02 PM.
Re: How much will valve spring dampers add to seat pressure [Re: A727Tflite] #3000725
01/01/22 05:04 PM
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Originally Posted by Transman


All the aftermarket springs that use them include the damper in the rates.

Again, the seat pressure is not affected by the damper.

I looked through all my papers and can’t find the damper rate in the AMA papers, so I grabbed a stock max wedge spring from back in the day.

On my scale accurate to a gram it shows 6.9# just before bind.



In other words, insignificant. Thanks for doing this, real world data is invaluable.


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Re: How much will valve spring dampers add to seat pressure [Re: 6PakBee] #3000747
01/01/22 05:45 PM
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big blocks used a dampner spring. the only modern type spring i know of that didn't use one were interference fit dual springs.

Re: How much will valve spring dampers add to seat pressure [Re: A727Tflite] #3000990
01/02/22 12:44 AM
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Thanks for doing all that work on measuring the dampers. It was very helpful to me.

Re: How much will valve spring dampers add to seat pressure [Re: ragtop] #3001000
01/02/22 03:45 AM
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Originally Posted by ragtop
How much lbs of seat pressure will stock dampers add to stock small block single springs? Thank you.
What year and size S.B. work
I've change inner dampeners getting the coil bind height set up correctly, I'm going to guesstimate maybe 3 to 6 lbs .060 from coil bind by themselves confused


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)






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