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We continued to rotate the cam through to 0.015 inch on the closing side and recorded a figure of 74 degrees ABDC. This wheel indicates degrees 0 to 180 from TDC to bottom dead center (BDC). But to read the numbers as "after bottom dead center" we must count counterclockwise from the 180-degree mark to the pointer. This indicates 74 degrees ABDC, not 106 BTDC. Most cam cards specify the before and after numbers to make this easier to understand. This little idiosyncrasy trips up a lot of people, so watch out for it.