Dead Reckoning

A. Maberry maberry at U.WASHINGTON.EDU
Thu Jul 26 02:06:57 UTC 2001

Used in timing automobile engines. The timing is determined by the
uppermost travel (top dead center) of the number one piston (which equals
the point of maximum compression in the number one cylinder. It's
certainly been a long time since I tried to tune my own car, so
someone please correct me if I am mistaken.

maberry at

On Wed, 25 Jul 2001 Mark_Mandel at DRAGONSYS.COM wrote:

> (My reception of ADS-L seems to be FUBAR at the moment, so I'm looking at
> the web archive.)
> Another related use of "dead" 'exact' is "dead center", including "top dead
> center" and "bottom dead center" (abbr. TDC, BDC, iirc) for, hmm, I think
> it's automotive or mechanical terminology for something that revolves in a
> vertical plane. At either the 12:00 or the 6:00 position it won't move: in
> the former because it's perfectly balanced between falling left and falling
> right, and in the latter because it's already in its lowest energy state
> and has nowhere to fall to.
> -- Mark A. Mandel

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