【单选题】In a diesel engine, when refitting piston rings you should ①check the ring gap at the smallest diameter of the cylinder ②remove carbon from the ring groove
【单选题】The scavenging air ports are located at such a height that they are just exposed by the _______of the piston when the piston is in the bottom dead center position.
【简答题】As the piston again reaches BDC, the exhaust valve opens, but the intake valve remains closed. The piston moves upwards on the exhaust stroke to force the burnt gases out of the cylinder through the e...