德国大众公司的 4缸 2 0气门发动机首次用于批量生产的轿车上。该发动机每缸 3个进气门 ,2个排气门 ,这样使燃烧室空气混合更快、更均匀 ,发动机排气更迅速、更彻底。燃烧室空间得到更充分利用。采用可变凸轮轴结构 ,改变进排气正时 ,使发动机在高转速时获得尽可能高的功率 ;低 For the first time, Volkswagen’s 4-cylinder 20-valve engine is used in mass production cars. The engine has three intake valves per cylinder and two exhaust valves, which allows the combustion chamber air to mix faster and more evenly, and the engine exhaust more quickly and thoroughly. Combustion chamber space is more fully utilized. The use of variable camshaft structure, change intake and exhaust timing, the engine at high speed to obtain the highest possible power; low