piston 33 and the third piston 44 are near top of their motion and the second piston 39 and the fourth piston 47 are near bottom of their motion the spark plugs 23 30 will fire fuel and air in the combustion chambers 20 27 has been compressed and when the spark plugs 23 30 fire the fuel air mixtures ignite the resulting explosion drives the first piston 33 and the third piston 44 downward and the second piston 39 and the fourth piston 47 upward as the first piston 33 and the third piston 44 reciprocate the first piston rod 36 rotates the first set of cams 64 a 64 b the first piston rod 36 translates the first compression rod 78 such that the first compression plate 77 compresses air in the first air compression chamber 75 and the first piston rod 36 translates the second compression rod 83 such that the second compression plate 82 compresses air in the second air compression chamber 81 as the first piston 33 and the third piston 44 reciprocate the first piston rod 36 rotates a set of cams similar to the first set of cams 64 a 64 b on the opposite side of the cylinder rotation of the first set of cams 64 a 64 b provides rotation to the first power output shaft 67 and second power output shaft 68 and rotation of the similar set of cams on the opposite side of the cylinder.