Abstract: A piston is provided with a gapless ring positioned in a subport position. Specifically, the gapless ring is positioned between the air ports and the crankcase of the engine. The gapless ring includes a rail and an annular ring received within the rail. The ring includes a ring gap and the rail includes a rail gap. When the rail receives the annular ring, the ring gap and rail gap are spaced apart in a circumferential direction such that the gaps do not overlap. In certain embodiments, the rail includes a notch. When the annular ring is received within the notch, the annular ring and rail are biased against rotating with respect to each other. In certain other embodiments, the gapless ring includes an oil scraping surface.

Abstract: An engine is provided with a cylinder liner that extends beyond the surface of the crankcase surrounding the cylinder. When the engine is oriented in an inverted V-block configuration, the extension of the cylinder liner provides a barrier to oil that can pool on the crankcase surface and otherwise enter the interior of the cylinder, absent such a barrier.

Abstract: An air-shut off valve for an engine is provided to reduce the number of engine cycles that occur if an engine starts in reverse. The air shut-off valve includes a shaft centered on and extending along a longitudinal axis and a valve plate centered on a central axis. The valve plate is mounted on the shaft and positioned such that the central axis and the longitudinal axis do not intersect with each other. The valve plate can be actuated automatically (i.e., through air interfacing with the valve plate) or manually (i.e., by a user) between an opened position and a closed position with respect to the air intake tube.

Abstract: An oil tank for an engine is provided with a separator that reduces the amount of entrained air in the oil tank. The separator includes a body with an outer wall, a divider wall, and an outlet. The divider wall is located between the outer wall and at least a first portion of the outlet. The divider wall is offset from a curved portion of the outer wall, which defines a flow channel through which the oil flows towards the outlet. The oil increases speed as travels around the divider wall. This movement keeps the oil with some and/or more entrained air closer to the outer wall. In contrast, the oil with less or no entrained air moves closer to the divider wall and may travel more directly to the outlet.

Abstract: A wrist pin cap for a piston. The wrist pin cap is configured to form an interference fit with the piston. In specific embodiments, the wrist pin cap is positioned within the piston adjacent to an end of a wrist pin. In certain specific embodiments, the wrist pin cap is configured to form an interference fit with a counterbore of the piston. Some specific embodiments include a method for shrink fitting a wrist pin cap within a piston. In more specific embodiments, the wrist pin cap is shrunk by an application of liquid nitrogen.

Abstract: An engine is provided with a cylinder liner that extends beyond the surface of the crankcase surrounding the cylinder. When the engine is oriented in an inverted V-block configuration, the extension of the cylinder liner provides a barrier to oil that can pool on the crankcase surface and otherwise enter the interior of the cylinder, absent such a barrier.

Abstract: A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

Abstract: A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

Abstract: An internal combustion engine that includes a crankcase having a crankcase pressure defined within the crankcase relative to an ambient pressure. The crankcase pressure varies in response to operation of the internal combustion engine. A crankcase pressure regulator is in fluid communication with the crankcase, and the crankcase pressure regulator includes a first passageway defining a first flow path, a second passageway defining a second flow path in a parallel arrangement to the first passageway. When the crankcase pressure is less than a first predetermined pressure, the first valve moves to the open position to allow a fluid flow into the crankcase through the first passageway. When the crankcase pressure is greater than a second predetermined pressure, the second valve moves from the closed position to the open position to allow a fluid flow from the crankcase through the second passageway.

Abstract: A piston for an internal combustion engine, the engine having a connecting rod coupled to a wristpin, the wristpin being connected to the piston for pivotal movement about an axis, the piston comprising: a top portion and a generally cylindrically-shaped wall portion extending from the top portion, the top and wall portions defining a skirt cavity, the top portion having thereon a downwardly extending projection with a downwardly facing bearing surface for the wristpin, the bearing surface extending in the direction of the axis and defining a portion of a cylinder centered on the axis, and the projection having opposite sides facing the skirt cavity; at least one lubricant passage extending through the projection from one of the opposite sides and over the bearing surface to the other of the opposite sides; and a lubricant opening communicating between the lubricant passage and the bearing surface to supply lubricant to the bearing surface and to the wristpin.

Abstract: An internal combustion engine that includes a crankcase having a crankcase pressure defined within the crankcase relative to an ambient pressure. The crankcase pressure varies in response to operation of the internal combustion engine. A crankcase pressure regulator is in fluid communication with the crankcase, and the crankcase pressure regulator includes a first passageway defining a first flow path, a second passageway defining a second flow path in a parallel arrangement to the first passageway. When the crankcase pressure is less than a first predetermined pressure, the first valve moves to the open position to allow a fluid flow into the crankcase through the first passageway. When the crankcase pressure is greater than a second predetermined pressure, the second valve moves from the closed position to the open position to allow a fluid flow from the crankcase through the second passageway.

Abstract: Improved internal combustion engine, particularly, an improved two-stroke, diesel aircraft engine. The invention includes a new wrist pin/connecting rod connection, a new cooling system for fuel injectors, a new cylinder head cooling arrangement, a new cooling jacket cross-feed arrangement, and a new combustion seal arrangement.

Abstract: Improved internal combustion engine, particularly, an improved two-stroke, diesel aircraft engine. A first improvement includes a wrist pin/connection rod assembly. A plurality of fasteners extend through a wall of a wrist pin and into a wrist pin insert to secure the wrist pin to a cradle-like portion of a connecting rod. A second improvement includes a fuel injection system which cools fuel injectors with overflow fuel from a fuel pump. The overflow fuel is warmed as it cools the fuel injectors, thereby preventing ice-build up on a fuel filter in cold weather as the overflow fuel is recirculated to the fuel pump. A third improvement includes a new cylinder head cooling arrangement. The cylinder head and a cooling cap define an annular cooling passageway. Cooling fluid flows through the annular cooling passageway to cool the cylinder head. The cooling cap includes an inlet port and an outlet port which are not diametrically opposed.