No shim clearance, now what...

[Guest]

Hi,
Checked my valve clearances just a few minutes ago. My smallest feeler is .02mm.
All of the valves are <.02mm ! 26,600 miles on the engine. Should I assume there is no clearance and go with something that would give me .06mm-.08mm?

Thank you!
Andy

[jeff.saunders]

Assuming you can spin the bucket, then you know you have better than zero - so between zero and .02mm drop 1 shim size.

If you cannot spin the bucket, then you have less than zero - so you might need to drop 2 shim sizes

[Mr.Mom]

I can spin the buckets. A couple were a bit snug but still moved. Thanks Jeff.

[Steve]

Assuming you can spin the bucket, then you know you have better than zero - so between zero and .02mm drop 1 shim size.

If you cannot spin the bucket, then you have less than zero - so you might need to drop 2 shim sizes

I used to think that, too.

I got into one engine that I could spin the buckets on, but had to drop THREE sizes to get them in-spec.

Mr.Mom, have you inventoried your shims yet? When you know what all the sizes are, remove your thinnest one, replace it with a quarter. Move that thinest shim around to the other locations to see if you get a better idea on what you need.

Also, I would be remiss to not direct your attention to the invite in my signature.

.

[Mr.Mom]

Aghh 4 of the shims don't have markings anymore...?

[refeicul]

A digital caliper is your best friend in this case.

[Mr.Mom]

According to a digital caliper all of the mystery shims were 2.60. Ok off to order some shims.

Thanks!

[bwringer]

waitaminit...

Are you SURE you're using a metric feeler gauge?

The smallest feeler I've ever seen is .03mm, and it is an extremely fragile, whisper-thin piece of metal. It often sticks to an oil film and gets damaged before you can slide it between a cam lobe and shim. I can't even imagine how you'd work with a .02mm feeler.

A .002 inch feeler gauge would be right at .05mm, and while that's still pretty thin, you can use it normally. It's also in the safe valve clearance range.

[Chris G]

Are you SURE you're using a metric feeler gauge?

The smallest feeler I've ever seen is .03mm, and it is an extremely fragile, whisper-thin piece of metal. It often sticks to an oil film and gets damaged before you can slide it between a cam lobe and shim. I can't even imagine how you'd work with a .02mm feeler.

A .002 inch feeler gauge would be right at .05mm, and while that's still pretty thin, you can use it normally. It's also in the safe valve clearance range.

I have a set that lowest reading is .02mm fragile yes, but no issue when using to measure valve clearances.

[Brendan W]

According to a digital caliper all of the mystery shims were 2.60. Ok off to order some shims.

Thanks!

What does it say the marked ones were ?

[Mr.Mom]

marked 2.55(2.53, 2.54) ,2.60, 2.69

[Missile99]

It doesn't seem right that not even one is in spec with 26K. Don't most of these engines usually start with 2.75 / 80 shims? It almost sounds like the valves have been adjusted before.

Mr. Mom, what is the next increment in your feeler gauges? It should definitely be .03mm if your set has as low as .02 which I've not seen before. If not, then they are probably stuck together and need to be squeezed and slid apart like you were opening a garbage bag or a slowed down version of snapping your fingers.

[Mr.Mom]

I checked to make sure they were not sticking, checked multiple feelers .02, .03 etc.

[tkent02]

It doesn't seem right that not even one is in spec with 26K. Don't most of these engines usually start with 2.75 / 80 shims? It almost sounds like the valves have been adjusted before.

.

I haven't seen them that small except on old engines, agreed something is fishy.

[Mr.Mom]

Ok Thanks to Ray & the shim club I was able to get my valves back in spec. No one had 245 shims so I used the club. Some of them I dropped two sizes and they were still only .04mm-.05mm clearance! So my exhaust valves are running .08-.09mm and my intakes are .04-.05mm.

Thank you
Andy
From Wisconsin