An unthrottled multicylinder catalytic engine having first and second cylinders with first and second pistons, respectively, reciprocating therein. A mixture of air and fuel is inserted into the first cylinder, compressed in the first cylinder, and combustion is initiated, if necessary, during start-up. A transfer passageway communication between the first and second cylinders receives the compressed mixture and a catalyst positioned in the passageway oxidizes or ignites the mixture to provide the power stroke for operating the second piston. Thereafter, the oxidized or burnt mixture is exhausted from the second cylinder. The compressed gas may be heated in the passageway by the exhaust heat.
Robert H. Thring