Abstract: An internal combustion engine has a positive displacement supercharger which can be used with particular advantage in an underpumping two stroke engine which is in the form of a valved diaphragm which reciprocates in a housing to deliver positive pulses of air. The internal combustion engine also has an oiling system which includes injecting oil between the piston and cylinder walls at discrete time intervals and any excess oil is removed through galleries in the piston, connecting rod and main drive shaft preferably by a vacuum exerted on the galleries. Various other innovative features include a two part exhaust valve, generation of the vacuum by a positive displacement supercharger, a two-part cylinder head, use of inserts on moving parts to increase the efficiency of an underpumping engine and a specially constructed flywheel.

Abstract: A compression operated fuel injector assembly (1) for an internal combustion engine. The injector assembly (1) has a body (2) with a bore (8) having a gas passage (9) at one end for communication with an engine combustion chamber. A piston (7) is slidable in the bore (8). A fuel pump (5) is mounted within the body (2) having a plunger (14) which is mounted on the piston (7) for reciprocal pumping movement within a complementary fuel pump cyclinder (15) for delivery of fuel to a nozzle assembly (6). The nozzle assembly (6) is mounted on the piston (7) and projects through the gas passage (9).