Valve spring heights and shims

DavidC

Just FYI, I found a way to accurately determine installed valve spring height on 308. I had a machine shop make a 0.55 inch spacer the diameter of a shim and then used a 1.4-1.8 valve height micrometer to determine valve height. Let me know if you want further details. In the pic you see the spacer which goes in the spring cup, followed by the micrometer placed upside down. Cumbersome but accurate.

My Hudson manual gives an installed height of 2.188, but no +/- variance. I am using Dale Cooper supplied valves and springs. My exhaust seats were replaced with hardened ones (please don't start string about how unnecessary these are, as this was done long ago), thus the need to check spring heights.

I've checked 4 valves so far and I see a pattern. The intake valves, just cleaned up, measured 2.169 and 2.170. The exhaust were 2.196 and 2.222, both out of specs. Now for my questions...

Is the measure of 2.169 acceptably low? or would the spring pressure be excessive at this low height? Remember, this is a stock valve seat, so if it is too small it reflects too short of a valve stem (I have not compared the new stem to stock). I'm betting a valve height of 2.169 is just fine ,but ask for expert opinion.

To bring the exhaust valves into spec, and within 0.02 of the intakes, I need shims. Can anyone recommend a source?
Dave C

[Deleted User]

Dave-You didn't mention anything about what the spring pressure was at that height. A few more pounds of pressure won't hurt a thing. You only talking .019 and will boost the pressure less than 10 lbs. If your between 75-90lbs you will be fine.

Ol racer

FYI


Ive found shims available at most local machine Shops. I believe Chevy are the same dimension...

I failed to mention that some Machine Shops have Spring Pressure Tester, particularly an older Shop....

DavidC

Thank you Ol Racer, will check the locals for shims. When I looked at the size of most modern shims none seemed to match the ones I've seen on Hudsons, except some metric ones came real close. But maybe a local shop will have some stock.

Thanks Randy or Russ (sorry, don't know which). You're right, I did not mention spring pressure, as I have not found a local place to rent a spring pressure tester and purchasing one is a bit pricey. Maybe I can look on Ebay. I was hoping someone who has purchased the Dale Cooper springs had pressure tested them so I would know what ballpark pressure I am in. I think I better get my hands on a pressure tester. I got your cam and timing chain in there by the way. all lined up perfectly.

Dave

DavidC

One more thing: Can anyone tell me if the keepers are 7 deg or 10 deg? My best estimate with a protractor suggests 7 deg, and I'm looking at buying offset keepers vs shims to adjust installed valve height
Thanks for any help
Hudsonly,
dave

[Deleted User]

Dave-you are correct. The keepers are 7 degree. If you changed to 10 degree you would also have to change the retainer to match. Offset keepers will work also to accomplish your objective.
Randy

DavidC

Thanks Randy. Borrowed a spring pressure tester, shimmed all within 0.02 of each other, and got all closed pressures 76-78. Very happy. Thanks again
Dave