The Honda K series engine is a four-cylinder four-stroke engine. The K series engines are equipped with DOHC valvetrains and use roller rockers to reduce friction. The engines use a coil-on-plug, distributorless ignition system with a coil for each spark plug. This system forgoes the use of a conventional distributer based ignition timing system in favor of a computer controlled one that allows the ECU to control ignition timings based on various sensor inputs. The cylinders have cast iron sleeves similar to the B-series engines, as opposed to the FRM cylinders found in the H-series.