Crossflow cylinder head

Crossflow heads use overhead valves, but these can be actuated either by overhead camshafts, or by a valve-train, which has the camshafts in the cylinder block, and actuates the valves with push rods and rockers.

A crossflow head gives better performance than a Reverse-flow cylinder head (though not as good as a uniflow), but the popular explanation put forward for this — that the gases do not have to change direction and hence are moved into and out of the cylinder more efficiently — is a simplification since there is no continuous flow because of valve opening and closing.

In the UK, "Crossflow" is also used to refer specifically to Ford Motor Company's Kent Crossflow four-cylinder overhead valve engine, and its short-block "Valencia" derivative which has been used in cars from the 1960s up to the present day, albeit with the addition of fuel injection and a modern engine management system.

The term was also briefly used in the early 1980s in Australia for the revised 4.1 litre inline six-cylinder engine in Ford's Australian large family car, the Falcon.

This term is used for engines which have two intake and two exhaust valves per cylinder; four (or five) valves per cylinder result in engines having superior high RPM performance sourced from total port circumference, rather than the relative location of the ports.