Shimming valve springs
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From: Port Tobacco, MD
Shimming valve springs We're going to throw a new set of springs into a project motor this week and see how it holds up. This time we're going to shim the valve springs to .050 of coil bind and we just want to double check our math....
coil bind: 1.08
Clearance: .050
Cam Lobe/Rocker lift: .622 .627
So we're looking for an installed height of 1.752(intake) and 1.757(exhaust)
coil bind: 1.08
Clearance: .050
Cam Lobe/Rocker lift: .622 .627
So we're looking for an installed height of 1.752(intake) and 1.757(exhaust)
To shim the springs, you'll need a spring height micrometer. Pop the spring and re-install the micrometer in its place. When you know that height from the base of the spring cups to the underside of the retainer, you can then determine how much room you have.
Installed height (whatever dimension your micrometer reads)
- minus max valve lift of lobe on that spring
- coil bind height of spring
+ plus .050"
= amount to shim
I paid someone $40 at The Head Shop to do this for me but this is how Patrick G explained it to me.
Best wishes,
J.R.
Installed height (whatever dimension your micrometer reads)
- minus max valve lift of lobe on that spring
- coil bind height of spring
+ plus .050"
= amount to shim
I paid someone $40 at The Head Shop to do this for me but this is how Patrick G explained it to me.
Best wishes,
J.R.
I get the same numbers, but you may want to verify actual lift with your rockers with a dial indicator just to make sure since you will be running close to bind although with pushrod/rocker flex you will likely have more than 0.050" anyhow.
