OVERHEAD VALVE ENGINES: Colin Pape of France continues the description of his Step 3 and 3b engines starting with more on the reverser - Part V

摘要

There is an input slot and an exhaust slot for each cylinder and for each rotation direction on the rotor for this engine. These slots are cut symmetrically around the rotor shaft. I designed the system so that both input slots for each cylinder are pressurised at the same time. Since they are opposite each other this avoids the need for balance slots. The design of the rotor is shown in fig 22 and a few words are necessary to explain how the slots are arranged for reversing. First of all the cylinders and the crankshaft offsets are numbered 1, 2 and 3 starting at the drive belt end. When the engine turns clockwise, seen from the drive belt end, the 'firing' order is 1, 2 then 3. When the engine turns anti-clockwise the 'firing' order is 1, 3 then 2. The inlet and exhaust slots are cut to take this change into account automatically. For any given cylinder the slots are arranged symmetrically about the centre of the shaft. This does not seem to be the case if you look at the inlet slots for cylinders 2 and 3 but if you rotate slots g and h, 120deg. clockwise you will see that they look just like slots c and d and if you rotate slots k and 1,240deg. clockwise, they also look just like slots c and d.