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View Full Version : Valve Adjustment/Shims



pdexta
04-26-2013, 12:50 PM
Seems like a dumb question but have any of you guys done a valve adjustment on your NB's? I need to adjust my valves since I did a valve job, but I cannot find where to buy shims anywhere. I read about people putting them in a lathe to cut them down a bit and about people trimming the buckets to effectively lower the shim, but I can't find anything at all online to buy the shims themselves. If anyone has done an adjustment I'd love to hear some suggestions, mine are way out of spec after the valve job.

Agent☣Orange
04-26-2013, 12:59 PM
I'm at a loss where to get them either but I'm pretty sure Track will answer you pretty quick on MFz.

Joe Morreale
04-26-2013, 07:45 PM
This first poster has a supplier. I guess he uses Nissan shims.

http://forum.miata.net/vb/showthread.php?t=471 599&highlight=valve+shim

Joe Morreale
05-07-2013, 01:01 PM
I'm just guessing but since your valves are too tight you are going to have to either swap around or buy some shims that are too small, to make a gap. After that you'll need to plastigauge or carefully measure the gap to make zero clearance. Add the distance of your shim and the distance of zero clearance minus what the valve lash needs to be and that will be the size of the shim for that particular valve. I would suspect that all valves are out, however swapping shims around might get some valves into spec. A Digital micrometer would be most helpful in measuring the existing shims and the plastigauge, if used. If you need help keeping track of the numbers I'd be glad to be there. I read up a little on it. It's complicated.