Vehicle engine, esp. for motorcycles esp. with secondary air supply track connecting exhaust gas ducts and ventilation track, for compact construction

摘要

The engine (3) has a crosswise positioned crankshaft (9), and cylinders (32) and cylinder heads (31) positioned so that the cylinder axis incline forwards. An intake system is located above cylinder axis. A secondary air supply track forming a connection between exhaust gas ducts (31c) and a ventilation track, is positioned on the intake side above the axis in head section with cylinder head and cylinder head cover (35). The intake system is approximately straight as seen from the side of vehicle, and secondary air supply track and ventilation track are approximately parallel to intake system.