diesel engines

gas turbines

petrol engines

aircraft engines

half the operating speed

one-fourth of operating speed

250-300 rpm

60-80 rpm

exhaust valve opens at 35° before bot-tom dead center and closes at 20° after top dead center

exhaust valve opens at bottom ′dead center and closes at top dead center

exhaust valve opens just after bottom dead center and closes just before top dead center

may open and close anywhere

minimum temperature to which1 oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

temperature at which it solidifies or congeals

temperature at which it catches fire without external aid

indicated by 90% distillation temperature, i.e. when 90% of sample oil has distilled off

maximum pressure developed

minimum pressure

instantaneous pressure at any instant

average pressure.