In a reciprocating engine, the dead centre is the position of a piston in which it is either farthest from, or nearest to, the crankshaft. The former is known as Top Dead Centre while the latter is known as Bottom Dead Centre.

What does the phrase top dead center mean?

Definition of 'top dead center'

Top dead center is the position of an engine's piston when it is at the very top of its stroke. The piston has moved up towards the top dead center. The piston is said to be at top dead center when it has moved to a position where the cylinder volume is a minimum.

How do I find my TDC by myself?

1) Remove the spark plug and place a long screwdriver or piece of dowel rod through the spark plug hole so that it is resting on the face of the piston. As you rotate the engine (by hand), this will move up and down with the piston. When you see it has reached its highest point of travel, it is at TDC.