top dead center


Also found in: Acronyms.

top dead center

[¦täp ′ded ′sen·tər]
(mechanical engineering)
The dead-center position of an engine piston and its crankshaft arm when at the top or outer end of its stroke.

top dead center (TDC)

top dead center (TDC)click for a larger image
top dead center (TDC)click for a larger image
Topographical map
The position of the piston within the cylinder when the piston has reached its farthest uppermost (closest to the cylinder head and valves) position.
References in periodicals archive ?
Engineer a valve at the beginning of each intake manifold which will begin to open when its respective cylinders are at top dead center and will be fully closed when its respective cylinders are at bottom dead center.
One of the more popular entries was the Top Dead Center Scooter Club of Eugene.
Because the unique method of firing after top dead center is combined with a very fast moving power piston, the two biggest emission problems for diesel engines (NOx and soot) are eliminated or drastically reduced.
The Ikona tooth form is a patented non-involute profile consisting of a specifically matched external and internal tooth pair that provide maximum performance in the smallest size possible with no contact at top dead center.
Because of the unique method of firing after top dead center and a very fast moving power piston, the two biggest emission problems for diesel engines (NOx and soot) are eliminated or drastically reduced.
By that time, the piston has moved so far from top dead center, no work of any value was being performed.