ratio of the inlet gas usually lies between 8 1 and 12 1 that is the intake chamber has a volume of between 8 and 12 times higher than the volume of the chamber in which the ignition occurs for engines that use diesel as fuel the ignition candles are unnecessary employing the rudolf diesel cycle compression ignition and the design of the chambers is resized so that the compression rate is between 15 1 and 25 1 instead of between 8 1 and 12 1 as in the case of the otto cycle fig1 shows the internal combustion engine in section by the dot dash lines in the leftmost representation can be observed the admission windows completely exposed given the rotor position so is represented by continuous line only the intake manifold 12 is hidden so is shown by the dashed lines in centre we can see the assembly in section being possible to observe one of the two intake manifolds 12 and one of the two exhaust manifolds 13 and please note that in this position of the rotor and cutting there is a small gap between the rotor and the cylinder representing the exhaust chamber and it respective wall which prevents it to be exposed to the inlet window in the rightmost representation of fig1 we can see.