More generally, the dead center is any position of a crank where the applied force is straight along its axis, meaning no turning force can be applied. Crank-driven machines rely on the energy stored in a flywheel to overcome the dead center, or are designed, in the case of multi-cylinder engines, so that dead centers can never exist on all cranks at the same time. A steam locomotive is an example of the latter, the connecting rods being arranged such that the dead center for each cylinder occurs out of phase with the other one (or two) cylinders.
Top dead center for cylinder one is often marked on the crankshaft pulley, the flywheel or dynamic balancer or both, with adjacent timing marks showing the recommended ignition timing settings as decided during engine development. These timing marks can be used to set the ignition timing either statically by hand or dynamically using a timing light, by rotating the distributor in its seat.
In a multi-cylinder engine, pistons may reach top dead center simultaneously or at different times depending on the engine configuration. For example:
The concept of top dead center is also extended to pistonless rotary engines, and means the point in the cycle in which the volume of a combustion chamber is smallest. This typically occurs several times per rotor revolution; In the Wankel engine for example it occurs three times for every one revolution of the rotor.
By finding the volume of the cylinder using TDC and BDC and multiplying it by the number of cylinders you have, you will get your engine displacement.
If a single-cylinder steam engine stops in either of the dead center positions it must be moved off the dead center before it will re-start. In small engines this is done by turning the flywheel by hand. In large engines the flywheel is moved with a lever or "turning bar". Both operations must be done with care to avoid the operator becoming entangled in the machinery.
Wipo Publishes Patent of Daimler, Volker Heiderich, Thomas Koch, Johannes Ritzinger, Wilhelm Ruisinger, Friedrich Schmid and Tobias Weyand for "Combustion Method for Piston Combustion Engines" (German Inventors)
Feb 09, 2013; GENEVA, Feb. 9 -- Publication No. WO/2013/013756 was published on Jan. 31.Title of the invention: "COMBUSTION METHOD FOR PISTON...