Quick question - 348 valve clearance tol.

Hello again guys.

I did a valve clearance check while I had the valve covers off the other day (last documented valve adjustment was 12k miles ago).

The measurements were all pretty much the same:

INLET: 8 thou” gauge loose, 8.5 thou” gauge tight

EXHAUST: 13 thou” gauge loose, 13.5 thou gauge tight

I didn’t have a quarter thou gauge to narrow it down more but that gives an average of 8.25thou IN (0.21mm), and 13.25thou EXH (0.34mm).


OK, these are all in tolerance (0.2-0.25mm / 0.3-0.35mm) but I was surprised to see both sets at either end of the precscribed band. Then I read on ND’s primer page that this is sometimes the preferred zone to aim for. Can anyone shed any light on why this would be so?

Thanks,
Chris.

Not really a concern as it will be getting a full check again within 5k miles or so – just curious. Car is 92’ Euro tb (standard except for no cats).

 

Thanks Brian, that makes more sense.