Using feeler gauges

[gstallons]

Well , I haven't had them checked with The Bureau of Weights and Measures..... but I am satisfied with the results. They are all SnapOn brand.  

 P.S. I do hope you are BSin' me.

 

[Pressureangle]

Golly.

The easy answer is GO-NOGO. 

Insert the one you want for spec, then try to insert the next size up. If your spec goes and the next doesn't, you're there within a half a thousandth. 

Besides, there's more difference in 'factory' and 'RaceCo' spec than you can error at any given point. Don't overthink it. My engine is much happier with the hammering elves in the valve covers than the quieter factory spec, too.

[gstallons]

you got that rite.  Valves get tighter not looser. BTW , I use International specs.

Edited November 3 by gstallons

[Lucky Phil]

On 7/5/2008 at 4:26 PM, dlaing said:

Thanks! That makes perfect sense! (and may explain why my readings go off so fast )

Your readings "go off fast" because they are never correct the first time and here's the reason why. This is what a set of rocker arms look like at 40,000klm on a well looked after V11 sport engine. What are the chances of an accurate valve clearance check repeatability when the rocker pads look like this and the feeler gauge blade straddles this wear area when you check the clearances? You wont actually get the gap where the pad face meets the valve but some sort of average between the unworn and worn spot which will be less than where the valve stem meets the rocker pad on the wear area. So set your valves to 0.15 and end up with around 0.2-0.25 or so. Next time you do the clearances you have the gauge slightly off centre and on the worn area only and bingo a totally different reading and you scratching your head about clearances. You either need to use the feeler at the wear point or replace the rockers. It's a common issue. Pointless analysing Gauge "feel" until you've dealt with this.

   

Edited November 3 by Lucky Phil

[gstallons]

My rocker arms would look like the one on the right long enough to get some more and I would inspect the top of the valve to see what it looked like too . This stuff really needs looking at .