coil bind/valve shims

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Apr 4, 2006 | 04:05 PM

01350ss

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From: central east coast florida

coil bind/valve shims

I now have the trex cam and patriot gold springs. Install height is 1.800, spring coil bind is 1.090. Lift on my cam is .618 and .613
1.800 1.800
-0.613 -0.618
-------- --------
1.187 1.182
-1.090 -1.090
-------- --------
.097 .092
-.050 -.050
------- --------
.047 intake .042 exhaust

So this means that I need .047 shims for my intake valves and .042 shims for my exhaust valves. If this not correct please correct me.
Where can I get this amount of shims?

Apr 4, 2006 | 04:17 PM

vettenuts

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From: Little Rhody

Comp makes shims to fit our heads. They come in multiples of 0.015".

Apr 4, 2006 | 04:17 PM

ArKay99

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From: Washington Township, NJ

Quote:

Originally Posted by 01350ss

No, that means that is the maximum you SHOULD shim the springs, IF YOU WANT MORE SEAT PRESSURE. Also, a lot of guys will shim various amounts to equalize seat pressure. The idea is with an equal number of springs pressing on your lifters at an equal rate will give you zero actual valve train load so more hp, but you would have to measure the seat pressure of your springs individually and shim to equalize them. If you shim the springs .040" you will have an installed height of 1.760" assuming it IS 1.8" now. Have you checked the installed height on an assembled head? I thought it was 1.800" on mine, but it was 1.850" and there was .060" of shim under the seat. So check it first.
If all you are doing is installing a set of springs, I would just check that the installed height is 1.8" or within +-.010" of that. That should give you around the advertised seat pressure of 135lbs. Make sure you heat cycle them properly or the seat pressure could become inconsistent and lead to premature failure.

Apr 4, 2006 | 04:24 PM

01350ss

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From: central east coast florida

^ok, I will be measuring the springs, but if the springs are indeed 1.800 installed height, is my math correct to get the springs .050 from coil bind? If not than I'm a little lost.

Apr 4, 2006 | 04:25 PM

Gunnar@Patriot

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At 1.800" you should have right 140 lbs. As we said earlier, we can provide you with hardened .015" shims. If you decide to go ahead and shim them, let us know and we can sell you the hardened shims you will need.

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