Multi-valve cylinder heads are cylinder heads incorporating more than a single intake and single exhaust valve.
Multi-valve heads can have several advantages:
- two or more small valves can provide more gas flow than one large valve
- small valves are lighter and can raise the engine's safe working speed
- smaller intake ports promote higher gas speeds, which can improve combustion at part throttle
Multi-valve heads commonly have four valves (two intake, two exhaust) but three-valve heads (with two intake valves) and five-valve heads (with three intake valves) are also in use.