[zbone]

Вот для ценителей и знатоков подробно описано.

The idea is simple: measure the distance a piston moves, called the stroke, and multiply it by the area of the cylinder, remember that algebra thing?

The area is pi times the square of the diameter of the cylinder all divided by 4; easy enough. But the level of precision required is not so easy.

A standard piece of notebook paper is approximately 0.0025” to 0.0035” thick, depending on the quality of the paper, the humidity and temperature of the room and if you’ve touched the paper. The make or break measurement for Carl 2 Long is on the order of 0.0015”, or half the thickness of one sheet of paper.

Imagine yourself to be a dutiful NASCAR inspector: does this piston in the picture have a diameter of 0.735” or 0.736”? The dial indicator is in between. If your call is 0.735” then Carl 2 Long must be renamed as Carl The Legal; and if your call is 0.736” then Carl 2 Long is a cheat and a liar. Notice the indicator doesn’t have another level of precision, so we can’t say precisely if it is 0.735” or 0.736.” The precise number is something between those two values. Now you the honest, diligent inspector, must make a judgment call.

To be really thorough, the inspector should measure each of the eight cylinder diameters and strokes (not just measure one and then multiply by 8). The dial in our one example seems slightly over the rule limit of 0.735”. But the next one might be slightly under, and the total of all 8 cylinder measurements would still meet the rule.

There are a couple of stories circulating on the Internet, one is that both the bore and stroke were over, but each by less than 0.001"; the other is that the bore was o.k., but the stroke was too long by 0.00154" because the crank had been made for a different (smaller bore) engine and the parts got mixed up, even though the specifications sheet on the engine that Carl bought said it was a legal engine.

Both stories, however, match up in that only one cylinder was measured, then the results multiplied by 8. If true, this is simply inexcusable; just as one cylinder was oversize, another one could have been under by a similar amount.

The sad part of this is that NASCAR's mechanical inspection process may be as poorly thought out as their drug testing methods. Only in this case, Carl Long really does seem to be an innocent victim of someone else's mistake, and the penalty totally unjustified.