Camshaft: Description and Operation

The engine has twin overhead camshafts with large base circle diameter cams, providing a high lift but little stress. The camshafts are driven by a timing chain equipped with a self-adjusting chain tensioner. The camshafts act directly on the valves via hydraulic tappets.

The hydraulic tappets adjust automatically to differences in valve clearance caused by temperature variations. They operate in an oil bath, with oil supplied via an oilway in the cylinder head. The main advantages of these hydraulic tappets are their near-silent operation and high degree of reliability. The valves are made of steel and have chrome-plated stems. The heads of the exhaust valves are stellite