You, a neophite, cannot check piston to cylinder wall clearances with feeler gauges or calipers to any kind of accuracy.
Edit for Cope; It is nearly impossible to check skirt clearances with feeler gauges or calipers, to any kind of accuracy.Even after doing it hundreds and hundreds of times the correct way, feeler gauge comparisons fail miserably.Some might insist they have a feel for it.Perhaps there is ,or are a tech or two that do. I am not one of them.I have several decades of experience building motorcycle,Atv,Pwc,Marine,and sled engines.If an engine comes back to me with broken skirts or scuffed skirts, I can check the build sheet and say;"look here, this is the spec I set it to; and these are the tools I used.Do you think this has anything to do with your failures?"It will not say feeler gauges.
Feeler gauges act like little springs,throwing the "feel" off. But worse is,they are about 1/2 inch wide, so when you stick them in a curved recess,they measure two points,about 1/2 inch apart, but the middle measurement, the important measurement, they don't measure at all.Small error,one might say.Never-the-less, do you want to risk a come back?I sure don't.End Edit
I had a boss once, when I was learning sleds, who swore he could do it with a dial caliper. Since I came from motorcycles, I had measuring tools. So I let him wiggle and jiggle and fudge his way through his "technique."Then we miked it. Together. With my tools.His dial caliper went into the tool box and I never saw it again.
Next thing you know, there's a dial bore gauge in the tool cabinet, alongside a new mike set.
