exhaust valve
Noun
Meaning
a valve through which burned gases from a cylinder escape into the exhaust manifold
Source: WordNetHypernyms
Examples
After the opening of the exhaust valve, the exhaust stroke follows, but this (and the following induction stroke) are not shown on the diagram.
Cylinder heads fitted with cast-iron inlet valve guides, phosphor bronze exhaust valve guides, and renewable "Silchrome" steel-alloy valve seats.
At 4 the exhaust valve opens, and the pressure falls abruptly to atmospheric (approximately).