Abstract: The present invention provides an improved adjusting shim used in a valve train for an internal combustion engine for an automobile. The adjusting shim produced from a base material consisting of a ceramic material containing 80 to 98 wt. % of silicon nitride and/or sialon and has a porosity of not more than 3%, a bending strength of not less than 1.0 GPa and an impact compressive elastic limit (Hugoniot elastic limit) of not less than 15 GPa, wherein the base material is provided on the surface thereof which contacts a cam with a ceramic surface layer having a composition different from that of the base material and a hardness lower than that of the base material. The adjusting shim of the present invention enables a power loss of a valve train to be minimized; the abrasion resistance thereof to be improved; and the fuel economy, the performance and durability of an internal combustion engine to be improved.

Abstract: A four cycle internal combustion engine in which cylinders are arranged in pairs. The pistons in each pair of pistons are arranged to operate in tandem.A U shaped arm which is arranged to turn around a center is connected through one set of linkages to a pair of pistons and through a second set of linkages to a crank. The center of rotation of the said U shaped arm is arranged to move around a center in a manner which will change the length of the stroke of the pistons without affecting the compression ratio.A third "air pumping cylinder" is located midway between the two cylinders. This cylinder contains an "air pumping piston".A cam operated rotary valve which is located in the top of the air pumping cylinder will be turned to an intake port during the down strokes of the air pumping piston and will permit air to be drawn in to this cylinder.The rotary valve will be turned to a closed position during the up strokes of the air pumping piston. This will permit air to be compressed.

Abstract: A fuel supply system for an internal combustion engine having inlet porting and a fuel supply passage with valve means therein, the cross-sectional area lying within the outside passage walls being greater in the region of the valve means than in a region upstream of the valve means. Means are provided in the passage tending to equalize the velocity of the fuel flow through the supply passage in different regions thereof.