GB/T 726-1994 in English

《GB/T 726-1994往复式内燃机 旋转方向、气缸和气缸盖上气门的标志及直列式内燃机右机、左机和发动机方位的定义》由TC177（全国内燃机标准化技术委员会）归口，主管部门为中国机械工业联合会。
本标准规定了往复式内燃机（以下简称内燃机）的旋转方向和气缸编号的标志方法及气缸盖装在发动机上或拆下时气缸盖上气门标志方法。本标准还规定了直列式内燃机右机、左机及发动机各方位的定义、以便用来描述装在发动机上各零部（附）件的位置。本标准适用于陆用、铁路牵引用和船用往复式内燃机，但不适用于用作驱动农业拖拉机、道路车辆和飞机用发动机。可用于筑路机和推土机、工业用卡车动力以及目前尚无合适标准的其它用途的发动机。

Scope

This standard specifies the marking method of the rotation direction and cylinder number of the reciprocating internal combustion engine (hereinafter referred to as the internal combustion engine), and the marking method of the valve on the cylinder head when the cylinder head is installed on the engine or removed. This standard also stipulates the definition of the right engine, left engine and engine positions of the in-line internal combustion engine, so as to describe the positions of the parts (accessories) installed on the engine. This standard applies to land, railway traction and marine reciprocating internal combustion engines, but does not apply to engines used to drive agricultural tractors, road vehicles and aircraft. Engines for road and bulldozers, industrial truck power, and other applications for which there is currently no suitable standard.