Ignition timing Ignition timing In a spark ignition internal combustion engine, Ignition timing refers to the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke. The need for advancing (or retarding) the timing of the spark is because fuel does not completely burn the instant the spark fires, the combustion gases take a period of time to expand and the angular or rotational speed of the engine can lengthen or shorten the time frame in which the burning and expansion should occur. In a
Henderson archaic pigeon Henderson archaic pigeon The Henderson archaic pigeon ("Bountyphaps obsoleta"), or Henderson Island archaic pigeon, is an extinct bird in the Columbidae, or pigeon family. It was described in 2008 as a new genus and species from subfossil remains found on Henderson Island in the Pitcairn Group of south-eastern Polynesia. The genus was named for both the ship HMS "Bounty" with which, following the famous mutiny, Europeans first discovered the Pitcairn Islands, and for the former bounty the bird provided as food; with the Greek "phaps" (wild pigeon). The specific epithet comes from the Latin adjective for "extinct" or "forgotten about".