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