Valve clearances cont'd

[Anonymous]

i'm back and working on the gs again, i ordered a 2.5 shim, and measured the clearance where i knew there was a 2.8 before. now i've got a clearance of .0008 in

what tool could i use to measure clearances b/w the cam and valve? i just wanted to be sure that my clearances could change if i replaced the shim, but that's obviously too high a clearance.

thanks guys

[Poot]

A feeler Gauge.


I tried to get fat shims from the dealership, but they dont carry them , so I'll have to stick with what I got pretty much. only had to order 1 shim.

[mcconnell]

Do you mean you have a clearance of 0.008, which would be too large?

[Anonymous]

no no, i had mostly 2.8, 2.85, 2.75 and 2.9 shims. the clearances with them was zero for every single valve. i put a 2.75 where there was a 2.9 shim, and still had too little clearance..in essence, i'm going to have to get 8 shims, i think, because every clearance was zero, and still were zero with the smaller shims i have. i bought a 2.50 from CRC2, and put it where i had a 2.75, and the clearance b/w the shim and the cam were .008 inches (you measure in ten thousandths, right? .0015, .0020

i just need to figure out how to determine what shim sizes i need based on measurements with this 2.50. if the clearance is... like that one, .008, and the shim is 2.50 (or slightly thicker) would that mean, i need like a 2.60 or 2.65?

[bwringer]

Metric feeler gauges would be a really good idea here... I found mine at Advance Auto.

Or at least inch gauges with mm measurements printed on them prominently.

Once we're all speaking mm, this will get a lot easier.

If you really meant .008 in instead of .0008 with the new 2.50mm shim, you have about 0.20 mm of clearance. You need a new shim .15mm bigger to bring the clearance to .05mm. That's right in the middle of the acceptable range, which is .03mm to .08mm.

Therefore, order up a 2.65mm shim.

Personally, I'd order a 2.60mm and a 2.70mm too, just in case, but I'm anal-retentive like that.

You can get shims for only $4.95 each from the fine folks at Cycle Recycle II in Indy, so why not order up several?

http://www.crc2onlinecatalog.com/

In my experience, their aftermarket shims tend to measure .01 to .02mm fatter than marked, but YMMV. The shims fit perfectly and work great.

Also, I always measure shims when they come out to verify what's stamped on them. You can't read the markings on some shims, too. I used to use a micrometer and convert to mm with a chart, but I bought a digital caliper for $15 that is dead accurate and much easier to deal with.

[Anonymous]

yeah, i hardly see anyone using the metric measurements, so i've just avoided stating them.

CRC2 is where i got my shim-- how would you recommend getting the measurements for the others? stick the 2.50 in and get a measurement for each valve?

[bwringer]

Man, I hate thinking in inches!

If all your valves are too tight, then yes, install the 2.50mm shim, rotate the engine a couple of times to seat the shim and squeeze out excess oil, and then measure the clearance with a feeler gauge.

Covert the clearance to mm (inches X 25.4), then figure out how much bigger a new shim would need to be to get it in the range of .03 to .08 mm.

For example, if you had .010in clearance, that converts to 0.254mm. Shims come in .05mm increments, so the shim that would give you the right clearance would be .20mm bigger than the one that was in there, or 2.70mm.

If you had .005in clearance, you're pretty close. That's .127mm, so a 2.55 shim would put you at about .07mm clearance. That's near the upper end of the range, but that's perfectly OK -- a little looser is better than tighter.

Here's a little quickie chart for your situation:


When you install the new shims, double-check these clearances. Sometimes stuff happens, and the clearance doesn't turn out exactly as you expected.

[Poot]

you can also trade in shims at the dealership. I tried, but they didnt have proper shims for me

[Anonymous]

dur. i posted another question and answered it myself. thanks for the chart, sir, i appreciate it much.