However, Moto Czysz has designed a motorcycle engine with a triple overhead camshaft configuration, with the intake ports descending through the cylinder head to two central intake ports between two outside exhaust camshafts actuating one of two exhaust valves per cylinder each.
All valve drive systems in four stroke engines must both power the valves and time their opening and closing.
Although the term "twin cam" is often used to refer to DOHC engines, it is imprecise, as it includes designs with two block-mounted camshafts.
) Another performance advantage is gained as a result of the better optimised port configurations made possible with overhead camshaft designs.
With no intrusive pushrods, the overhead camshaft cylinder head design can use straighter ports of more advantageous cross-section and length.
The OHC valvetrain system may be driven by the crankshaft using the same methods as an OHV system, but in practice (and depending on the application), lighter weight and maintenance-free methods are more commonly used.
Compared with other camshaft drive systems, timing belts have low design, engineering and production costs, low noise levels, low mass (and consequently low inertia), low space requirements, and no need for lubrication.
SOHC designs offer reduced complexity compared with overhead valve designs when used for multivalve cylinder heads, in which each cylinder has more than two valves.