Valve Seals
Thread Starter
Drifting
Joined: Apr 2008
Posts: 1,687
Likes: 86
From: De Pere, WI
Valve Seals
Does anyone know of a company that make shorter than normal valve seals? After shimming my valve springs to get the correct installed height the valve seals won't seat for ****....I need a shorter one, anyone know of 1? I have Comp Cams 511-16....
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Guess I don't understand how shimming the valve springs effects the guide seals from not seating right on the stem, or not staying on the stem? How much shimming is needed to get the right spring installed height?
Thread Starter
Drifting
Joined: Apr 2008
Posts: 1,687
Likes: 86
From: De Pere, WI
the shims go under the spring seat. This raises the height of the spring seat and decreases how much the valve seal can go on the valve guide. On average, I am having to shim them .15". .14" would have been ideal but I was unable to find a .010 shim.
Thread Starter
Drifting
Joined: Apr 2008
Posts: 1,687
Likes: 86
From: De Pere, WI
The comp 921 spring has an installed height of 1.77". The installed height unshimmed was anywhere from 1.905" - 1.920". Excessive spring installed height will reduce valvetrain stability, longevity, and close seat pressure.
Thread Starter
Drifting
Joined: Apr 2008
Posts: 1,687
Likes: 86
From: De Pere, WI
Holy **** me to tears....the spring micrometer I have is not calibrated for ****. it is calibrated to the TOP of the tool, not where the retainer sits. WTF kind of **** is that? There is a .15" difference between where the retainer sits and the top of the tool....how the **** did they screw this up? Never again will I buy anything from Howard's Racing Cams. The tool is going back along with the $40 in shims....so ****ing pissed!
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Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I am not following. The micrometer always measures from end to end. If you use it for beehive springs the retainer will fall down into the top of the micrometer and you either need to account for that distance in the measurement or make a shim to correct for the height difference and bring the beehive retainer level with the top.
That being what it is, I thought the 921's were dual springs so the retainer should sit on top. Also, if the seals are one piece seal/seat, then the shims go on top of the seals not under them.
That being what it is, I thought the 921's were dual springs so the retainer should sit on top. Also, if the seals are one piece seal/seat, then the shims go on top of the seals not under them.