What is the shim thickness and how did you get there

[chiz]

Folks I started to do my valves about a year ago and went a bit off target and ended up not going any farther. Anyway I have an example and would like an opinion.
Take my measured clearance of the exhaust valve on far left at .005 or .13mm with a 265 shim in there, what would be the replacement size? and how did you arrive at this #
Lastly would you set the exhausts above .008? and how does .004 right across all intakes some tight to snug sound to you folks?

Thanks Chiz

[Pat Conlon]

You can play with this: http://www.dev8.us/shimcalc/
I'm old school, I try not to over think it...I just follow the table.

I have learned this the hard way: After I change my shims, I must run my engine to seat the new shims before I remeasure the clearances.

Drove myself crazy.

[Tuned forks]

In addition to Pat's comments, get Robert to email you a chart for your measurements, old and new shim sizes.  It sure helps keep the math straight and you can also see trends and patterns in your engine.  Although Pat's mention of running your engine to settle in the shims is a bother with reinstalling the cam cover and fuel tank et al, it's totally worth it.  You would be surprised and perhaps disappointed at how things change.

Joe

[racerrad8]

how does .004 right across all intakes some tight to snug sound to you folks?

Thanks Chiz

Terrible.

.008 exhaust
.006 intake

Every service manual, whether GYSM or aftermarket has the valve shim chart in it. You document the measurement & remove the shim. Go to the chart and find .13(.05") and 265 and it tells you to install a 260.

The chart is priceless and all I use when adjusting valves.

As Pat already mentioned, you cannot accurately recheck the measurements after changing the shims. The oil pool gets under the shim and will give you erroneous readings. You have to run the engine up to temp and them let it cool all the way back down to recheck them.

Randy - RPM