- The primary compression in a two-stroke engine located below the pistons and enables a more fresh charge to be fed into the cylinder. Also called "crankcase pre-compression."
Dictionary of automotive terms. 2015.
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compression —  Applying pressure to a spring, or any springy substance, thus causing it to reduce its length in the direction of the compressing force.  Applying pressure to a gas, thus causing a reduction in volume.  One of the essential factors in a … Dictionary of automotive terms
crankcase pre-compression — See crankcase compression … Dictionary of automotive terms
Crankcase — For other uses, see Crankcase (disambiguation). De Dion Bouton engine from about 1905, in which can clearly be seen a discrete crankcase with upper and lower halves (each a casting), with the bottom half constituting both part of the main bearing … Wikipedia
Compression ratio — For compression ratio in data compression, see data compression ratio. The compression ratio of an internal combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its… … Wikipedia
primary compression — A term that is used in two stroke engines. Primary compression takes place in the crankcase and is then pushed up into the combustion chamber where secondary compression takes place as the piston squeezes the mixture. If the crankcase seals are… … Dictionary of automotive terms
secondary compression — A term that is used in two stroke engines. Primary compression takes place in the crankcase and is then pushed up into the combustion chamber where secondary compression takes place as the piston squeezes the mixture. If the crankcase seals are… … Dictionary of automotive terms
Variable compression ratio — is the technology to adjust internal combustion engine cylinder compression ratios on the fly. This is done to increase fuel efficiency while under varying loads. Higher loads require lower ratios to be more efficient and vice versa. Variable… … Wikipedia
primary compression ratio — The degree of compression achieved in the crankcase area below the piston of a two stroke engine when the piston moves down and compresses the mixture supplied into the crankcase … Dictionary of automotive terms
pre-compression — See crankcase pre compression … Dictionary of automotive terms
gasoline engine — Most widely used form of internal combustion engine, found in most automobiles and many other vehicles. Gasoline engines vary significantly in size, weight per unit of power generated, and arrangement of components. The principal type is the… … Universalium