. . . "an internal-combustion engine in which an explosive mixture is drawn into the cylinder on the first stroke and is compressed and ignited on the second stroke; work is done on the third stroke and the products of combustion are exhausted on the fourth stroke"@en-us . . "103388990"^^ . . "03388990-n"^^ . "0"^^ . "0"^^ . . . "103265384"@en-us . . . . "four-stroke engine"^^ . "four-stroke internal-combustion engine"@en-us . "four-stroke engine"@en-us .