Eight-stroke engine cycle

摘要

An eight-stroke engine cycle may include a first stroke forming an intake stroke and including opening an intake valve and providing a first fuel mass to the combustion chamber. The second stroke may form a first compression stroke and the third stroke may form a first expansion stroke including a first power stroke. The fourth and sixth strokes may form a second and third compression strokes and the fifth and seventh strokes may form a second and third expansion strokes. A second fuel mass may be provided to the combustion chamber during the fourth or sixth stroke. The intake valve may be in a closed position during the second and third expansion strokes and an exhaust valve in communication with the combustion chamber may be in a closed position during the second and third compression strokes. The eighth stroke may form an exhaust stroke including opening the exhaust valve.