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-   -   Valve lash (https://www.miataturbo.net/engine-performance-56/valve-lash-101859/)

Ramonn Jan 4, 2020 04:54 PM

Valve lash
 
Assembling my 2004 head i checked the clearance between the (solid) valve lifters and the cam lobes. I did so because I could recall a
about adjusting valve lash.

Now all lifters on the intake cam side had a clearance of 0.09 mm or 0.0035". All 8 of them did not clear the 0.10 mm or 0.004". Now I believe the clearance should be between 0.20 - 0.23 mm or 0.008" - 0.009". Head seemed stock when I disassembled it.

Now I did lap the valves and upgrade the springs to the volvo 418737 valve springs but that's it. Other than that the head is stock.

Could any of the above have caused clearance differences this much? Or is it supposed to be that way? I feel like I should get smaller shims although the clearance is exactly the same across the board. I had to cut it short so will be installing exhaust cam tomorrow and check those clearances as well.

Thnx
Ramon

patsmx5 Jan 4, 2020 04:57 PM

You will need to set the valve clearance to spec. It should be in spec.

tomrev Jan 4, 2020 06:47 PM

Lapping the valves will sink them in the head a slight amount , and .003 in. is not enough clearance to cope with expansion when running at temp. So, yeah, you need to set the clearance to correct specs.


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