Tappet/Pallet Shims

[ChrisD]

Hi,

I have been checking my valve clearances. When I measure my Tappet shims using a digital vernier calliper the sizes vary between .061 and 091 thou, which seems thin when I compare them with the replacement shims sizes which seem to in the range 0.090 to 0130 thou.

Am I doing something wrong or is it normal to have shims/pallets of this size? If it is normal where do I get shims of this size?

Also is a digital vernier caliper accurate enough to measure the shim or do I need to use a micrometer?

Thanks in advance

Chris

[StagJonno]

James Paddock do tappet shims starting from 70 thou

[trunt]

Also Look at lotus and SAAB. They use the same shims..

[jbuckl]

A vernier is also referred to a a very near.
An imperial micrometer is recommended.
A high quality digital caliper e.g. mitutoyo would work though, but they typically cost quite a bit more.
Usually if the heads need less than an 85 thou shim it’s because the seats have worn & been cut deeper.
Beware of grinding down valve stems or shims too much. They may be too soft after more than a few thou is taken off.

[mole42]

I use a ball-ended Moore & Wright Imperial micrometer to measure shims. There's often a depression in the centre of the shim where it sits on the valve head and it is important to measure the actual thickness at the point where the shim operates. A vernier caliper will give you an approximate result.

[richardthestag]

micrometer every single time for me, vernier will give you an approximate size as has been said ^^^

[trunt]

4C578398-253B-41FD-B420-D78FB6258980.jpeg



My Dad was an engineer and had a lifetime of measuring tools when he retired. Even though many went to the apprentices, as was tradition, I got a few and this dial gauge was perfect for those shims..

[jakesmig]

4C578398-253B-41FD-B420-D78FB6258980.jpeg



My Dad was an engineer and had a lifetime of measuring tools when he retired. Even though many went to the apprentices, as was tradition, I got a few and this dial gauge was perfect for those shims..

That's a knuckle duster which measures the strike force.

[Richard G]

Been doing mine, Rimmers dont do thinner sizers but Robsport do.....

[mole42]

There's a chap in the Hillman Imp community does some very thin shims. Don't remember his name but my engine has a few in there!

[ChrisD]

Hi

Thanks for all the replies.

All sorted now, I bought a micrometer and ordered the shims from QED Motorsport. (I was extremely pleased with their service) The shims are available from 0.060" in 0.001 increments.

Regards

Chris