In a reciprocating engine, the dead centre is the position of a piston in which it is furthest from, or nearest to, the crankshaft. A reciprocating engine, also often known as a piston engine, is a Heat engine that uses one or more reciprocating Pistons to convert The former is known as top dead centre (TDC) while the latter is known as bottom dead centre (BDC).

More generally, the dead centre 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 centre, or are designed, in the case of multi-cylinder engines, so that dead centres can never exist on all cranks at the same time. A flywheel is a mechanical device with significant Moment of inertia used as a storage device for Rotational energy. Engine configuration is an Engineering term for the layout of the major components of an Internal combustion engine. A steam locomotive is an example of the latter, the connecting rods being arranged such that the dead centre for each cylinder occurs out of phase with the other one (or two) cylinders. A steam locomotive is a Locomotive powered by Steam. The term usually refers to its use on Railways but can also refer to a "road locomotive"

Bicycles

Bicycle cranks have dead centers at approximately 12 o'clock and 6 o'clock where simple pushing down of the pedal will not turn the chainwheel, but the rider's leg is able to apply tangential force at the pedal to overcome it. The bicycle, cycle, or bike is a pedal-driven, human-powered vehicle with two wheels attached to a frame, one behind The crankset, or chainset, is the component of a Bicycle Drivetrain that converts the reciprocating motion of the rider's Legs into rotational Fixed gear bicycles (without a freehub) use the momentum of the bicycle and rider to keep the chainwheel turning even if the rider makes no attempt to pedal in a circular motion. A fixed-gear bicycle or fixed wheel bicycle, is a Bicycle without the ability to coast A freehub is an Axle assembly used notably for the rear axle of bicycles In Classical mechanics, momentum ( pl momenta SI unit kg · m/s, or equivalently N · s) is the product

Internal combustion engine

Top dead center is the datum point from which engine timing measurements are made. For example, ignition system timing is normally specified as degrees before top dead center (BTDC) although a very few small and fast-burning engines, require a spark just after top dead center (ATDC), such as the Nissan MA engine with hemispherical combustion chambers, or hydrogen engines. An ignition system is a system for igniting a fuel-air mixture The MA is an all aluminium Straight-4 SOHC 09 L 10 L or 12 L engine made by Nissan. A combustion chamber is the part of an Engine in which Fuel is burned A hydrogen vehicle is a Vehicle that uses Hydrogen as its on-board fuel for motive power

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. A flywheel is a mechanical device with significant Moment of inertia used as a storage device for Rotational energy. A timing mark is an indicator used for setting the timing of the Ignition system of an Engine, typically found on the Crankshaft pulley (as pictured or 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. A timing light is a Stroboscope used to dynamically set the Ignition timing of an Otto cycle or similar Internal combustion engine. A distributor is a device in the Ignition system of an Internal combustion engine that routes High voltage from the Ignition coil to the

In a multi-cylinder engine, pistons may reach top dead center simultaneously or at different times depending on the engine configuration. Engine configuration is an Engineering term for the layout of the major components of an Internal combustion engine. For example:

• In the V-twin configuration, the two pistons reach TDC at different times, equal to the angular displacement between the cylinders. Configurations "True V-twin" vs V-2 There is some ambiguity regarding what defines a V-twin which arose from 180 degree "V" engines (see Angular displacement of a body is the Angle in Radians ( degrees revolutions) through which a point or line has been rotated in a specified
• In the flat twin configuration, two opposing pistons reach TDC simultaneously, which is also called 0° displacement. A flat-twin is a two cylinder Internal combustion engine with the cylinders arranged on opposite sides of the crankshaft
• In the straight-4 configuration, the two end pistons (pistons 1 and 4) reach TDC simultaneously, as do the two center pistons (pistons 2 and 3), but these two pairs reach TDC with an angular displacement of 180°. The straight-4 or inline-4 engine (often abbreviated I4 or L4) is a four cylinder Internal combustion engine with all four cylinders Similar patterns are found in almost all straight engines with even numbers of cylinders, with the two end pistons and two middle pistons moving together (not necessarily 180° out of phase however) and the intermediate pistons moving in pairs in mirror-image around the center of the engine. Usually found in 4- and 6- cylinder configurations the straight engine (often designated Inline engines is an Internal-combustion engine with all cylinders
• In the flatplane V8 and many larger V engines, the piston motion within each bank is similar to that of a straight engine, however in the crossplane V8 and all V10 engines the motion is far more complex. A V8 engine is a V engine with eight cylinders mounted on the Crankcase in two banks of four cylinders in most cases set at a right angle to each other A V engine is a common configuration for an Internal combustion engine. The crossplane or cross-plane is a Crankshaft design for V8 engines with a 90° angle between the cylinder banks A V10 engine is a V engine with 10 cylinders in two banks of five

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 article is about Internal combustion engines that do not use conventional Pistons See also Rotary engine (disambiguation for other uses of this 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. The Wankel engine is a type of Internal combustion engine which uses a rotary design to convert pressure into a rotating motion instead of using reciprocating

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.

Steam engine

As steam engines are commonly horizontal, the relevant terms are front dead centre and back dead centre rather than "top" and "bottom". A steam engine is a Heat engine that performs Mechanical work using Steam as its Working fluid. In Astronomy, Geography, Geometry and related sciences and contexts a plane is said to be horizontal at a given point if it is locally

If a single-cylinder steam engine stops in either of the dead centre positions it must be moved off the dead centre before it will re-start. In small engines this is done by turning the flywheel by hand. A flywheel is a mechanical device with significant Moment of inertia used as a storage device for Rotational energy. 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.

Steam locomotives normally have two cylinders with the cranks set at right angles so one piston will always be off the dead centre and no starting assistance is required. A steam locomotive is a Locomotive powered by Steam. The term usually refers to its use on Railways but can also refer to a "road locomotive" A crank is an arm at right angles to a shaft (an Axle or spindle by which motion is imparted to or received from the shaft it is also used to change circular into Reciprocating In Geometry and Trigonometry, a right angle is an angle of 90 degrees corresponding to a quarter turn (that is a quarter of a full circle A piston is a component of Reciprocating engines Pumps and Gas compressors It is located in a cylinder and is made gas-tight by Piston

Other machines

This term is also used in the realm of production equipment. A mechanical punch press employs a crankshaft similar to that found in an engine. In the punch press the crankshaft drives a ram which when it is farthest away from the platen of the press is considered to be in the position of top dead center.