The Suzuki GSX-R/4 is a concept car made by Suzuki in 2001. Designed as a showcase for technology, it was never meant for production.
A multi-valve or multivalve four-stroke internal combustion engine is one where each cylinder has more than two valves – more than the minimum required of one of each, for the purposes of air and fuel
A cylinder head of a four-valve Nissan VQ engine
Cutaway model of Subaru's i-AVLS variable valve timing system on SOHC 4-valve-per-cylinder EJ25 boxer engine at Tokyo Motor Show 2007.
Combustion chamber of a 2009 Ford Ecoboost 3.5-liter turbocharged V6 petrol engine (77.8 kW/liter) showing two intake valves (right), two exhaust valves (left), centrally placed spark plug, and direct fuel injector (right).
A cylinder head from a 1987 Honda CRX Si showing SOHC, rocker arms, valve springs, and other components. This is a multi-valve configuration with two intake valves and one exhaust valve for each cylinder.