the elder engine is able to harness this force to increase the efficiency of the engine this force acts to pull the disk in the proper direction as the heated helium acts to push the disk in the proper direction all three of these forces work together for maximum efficiency in contrast in an internal combustion engine a fuel air mixture is compressed into a small space by a piston and then ignited by a spark plug to produce a small explosion the pressure created by the explosion forces the piston back downwards there are no rotational forces or rapidly moving helium available to assist in this process the elder engine creates rotational force as it works while an internal combustion engine creates reciprocating force an internal combustion engine requires a crankshaft to translate its reciprocating force into rotational force at a substantial loss of engine power and engine efficiency in contrast an elder engine has no need of a crankshaft and is able to translate much more of its mechanical energy into useful work the disk assembly has small vent holes that correspond with the vent openings to the heat exchanger when the disks have rotated clockwise to the proper position approximately 90 degrees from the original starting position the hot helium gas is exhausted to the compression rotor through a heat exchanger there.