Abstract: An internal combustion engine having an engine block containing a plurality of cylinder bores and a piston slidably mounted in each bore. The block is composed of a hypereutectic aluminum-silicon alloy containing from 16% to 30% silicon and having precipitated primary silicon crystals, while the piston is composed of an aluminum-copper alloy containing from 10% to 15% by weight of copper.

Abstract: A two-cycle, water-cooled marine engine having an engine block composed of a hypereutectic aluminum-silicon alloy. The silicon is distributed as discrete particles throughout the block, including the area bordering the walls of the cylinder bores. An aluminum piston is mounted for movement within each cylinder bore and the outer peripheral surface of each piston is plated with iron. With the iron plated piston in combination with the aluminum silicon alloy engine block, the engine is capable of being restarted after the engine seizes due to overheating caused by a blockage of the water cooling system.

Abstract: An evaporable foam pattern for casting the engine block of a two-cycle engine. The pattern has a crankcase end and a head end and a plurality of cylinders extend from the crankcase end toward the head end. A plurality of transfer passages are disposed longitudinally of each cylinder and one end of each transfer passage communicates with the crankcase end, while the second or discharge end of the transfer passage communicates through a transfer port with the cylinder adjacent the head end of the pattern. The pattern is composed of a crankcase section and a head section which are joined along a parting line disposed normal to the axis of the cylinder, with the parting line intersecting the transfer passages adjacent the discharge end of the passages. A portion of the cylinder in the head section located adjacent the parting line is enlarged in diameter and is connected to the cylinder by a plurality of ledges that are disposed between the transfer passages.

Abstract: An evaporable foam pattern assembly for casting a housing for a rotary engine. The pattern assembly includes a central rotor chamber pattern section and a pair of end pattern sections which, in the cast engine, are mounted on either side of the central section. The cental pattern section is provided with a central chamber of epitrochoidal shape and the end sections are each formed with a central opening. The outer portion of each central opening is cylindrical in shape, while the inner portion is elliptical and separated from the outer portion by a relief groove. Each end pattern section is provided with an air passage that communicates through the relief groove with the elliptical opening, so that in the assembled cast engine, air introduced into the passage of one of the end sections flows into the rotor chamber of the central section and is discharged from the other end section.

Abstract: A cooling water system for a rotary internal combustion engine includes initial direct water cooling for the outer surface of the exhaust manifold with the cooling water directed therefrom to serially interconnected cooling water passages in the various housing elements comprising the engine block. The cooling water passage in each housing element is circumferentially disposed along the peripheral portion of the housing which is directly adjacent the high temperature exhaust and combustion areas of the engine rotor chamber. The cooling system thus supplies water directly to the portions of the engine subject to the highest operating temperatures. The system also includes protection against the formation of hot air or steam pockets and the cooling system is readily adaptable to both single and twin rotor engines.

Abstract: A tuned combustion air intake system for a rotary engine includes a plenum chamber mounted on the engine block and receiving cooling air discharged therefrom. Air from the plenum chamber is directed into an elongated outlet conduit of a extended length determined to provide an optimum pulsed air flow to the combustion air inlet to the carburetor. The extended length outlet conduit is wrapped at least partially around the plenum chamber to provide a compact construction particularly suitable to adapting the engine for use in an outboard motor. A supplemental air outlet from the plenum chamber to a downstream portion of the outlet conduit may be utilized to bypass a portion of the conduit to provide a change in the tuned length thereof for optimizing performance at difference engine speeds.

Abstract: A lubricating system for a rotary internal combustion engine includes an oil supply chamber at one end of the rotorshaft to which lubricating oil is supplied by an engine driven oil pump. The oil is caused to flow from the chamber along the rotorshaft and into the interfaces between the various rotating engine components attached to the rotorshaft. In the preferred orientation of the engine with the rotorshaft vertically disposed, oil flow is primarily under the influence of gravity. Oil accumulating in a sump at the lower end of the rotorshaft is circulated to the combustion region of the rotor chamber, utilizing the inherent pressure differential therebetween, where it provides further engine lubrication and is eventually burned. Lubricating oil may also be picked up and circulated from the main supply dispersed along the rotorshaft by the circulating supply of cooling air through the engine, whereby it is transferred in the combustion air supplied to the carburetor.

Abstract: In a two stroke internal combustion engine (2) having a pair of spark plugs (28, 30) for each cylinder (6), a particular height and spacing ratio of the spark gaps (32,34) have been found to produce misfire-free running during idle. The ratio h/H should be less than 0.5, where h is the height of the spark gaps (32, 34) above the squish surface (20) or the top (60) of the cylinder sidewalls, and H is the height of the top (36) of the combustion chamber above such surface. The ratio d/D should be in the range of about 0.25 to 0.35, where d is the distance between the spark gaps (32, 34), and D is the inner diameter of the cylinder (6).

Abstract: A hypereutectic aluminum-silicon casting alloy having particular use in casting cylinder blocks for marine engines. The alloy is composed by weight of 16% to 19% of silicon, 0.4 to 0.7% magnesium, up to 0.37% copper and the balance aluminum. With the stated silicon content the alloy has good fluidity and the precipitated silicon crystals provide excellent wear resistance. In addition, the alloy has a narrow solidification range of less than 150.degree. F., thereby providing the alloy with excellent castability. The copper content is maintained at a minimum so that the alloy has improved resistance to salt water corrosion.

Abstract: A hypereutectic aluminum-silicon casting alloy having particular use in casting cylinder blocks for marine engines. The alloy is composed by weight of 16% to 19% of silicon, 0.4 to 0.7% magnesium, up to 0.37% copper and the balance aluminum. With the stated silicon content the alloy has good fluidity and the precipitated silicon crystals provide excellent wear resistance. In addition, the alloy has a narrow solidification range of less than 150.degree. F., thereby providing the alloy with excellent castability. The copper content is maintained at a minimum so that the alloy has improved resistance to salt water corrosion.

Abstract: A stratified-charge cross-flow scavenged two-stroke cycle spark-ignition engine (1) includes a piston (2) having a raised crown (6) with a baffle (7) and chamfered sides (8, 9) and reciprocal in a cylinder (3) between a combustion chamber (4) and a crankcase (5). Transfer passage structure is disclosed wherein a pair of elongated scavenging air passages (17, 18) extend between the crankcase and combustion chamber on opposite sides of a shorter fuel-air transfer passage (11). A pair of scavenging air inlet ports (20, 21) in the combustion chamber are adjacent the fuel-air inlet port (12) therebetween and substantially distally opposite the exhaust port (16). The scavenging air inlet ports face the baffle at its edges along the chamfered sides of the piston crown.

Abstract: A stratified-charge two-stroke cycle scavenged spark-ignition engine 1 includes a piston (2) reciprocal in a cylinder (3) between a combustion chamber 4 and a crankcase (5). A carburetor (17) is mounted to the crankcase substantially coaxially with the piston to afford narrow engine design. An elongated scavenging air passage (14) extends between the crankcase and the combustion chamber and has a length substantially greater than that of a fuel-air transfer passage (7), and the height of piston (2), to reduce fuel mixture in the scavenging air passage and afford substantially only air at an air inlet port (16), which port is between fuel-air mixture inlet port (8) and exhaust port (13).

Abstract: A crankcase supercharged four cycle engine (10) includes an outside air inlet port (22) positioned so that upon each expansion stroke of the piston (11) a discrete pulsed charge of pressurized air is fed to the crankcase (15), and hence from the crankcase through a one-way valve (26) into surge tank (28). The surge tank chamber (29) is connected through a tuning pipe (31) to a manifold volume chamber (34) leading to the air intake (20) of the engine cylinder (12). The tuning pipe is designed with the correct length and volume to provide a resonant frequency which increases engine torque at low speed. The construction provides a closed loop connection (24) between the crankcase and engine cylinder which is subjected to air pressure pulses which are directly responsive to the frequency of reciprocation of the piston. A pressure multiplier effect is obtained within the loop to substantially increase the pressure of air ultimately fed to the cylinder.

Abstract: A crankcase supercharged four cycle engine (10) includes an outside air inlet port (22) positioned so that upon each expansion stroke of the piston (11) a charge of pressurized air is fed to the crankcase (15), and hence through a one-way valve (25) and nozzle (26) into an enclosed surge tank (28). A tuning pipe (30) disposed within the surge tank has an inlet (31) at the nozzle outlet and provides a tuned passage which connects for discharge through a valved port (20, 21) into the engine cylinder (12). On one downward stroke of the piston, air from the outside air inlet port is compressed into the crankcase and is forced through the one-way valve and nozzle to provide a charge of compressed air which is trapped within the surge tank and tuning pipe. On the next downward stroke of the piston, another charge of compressed air is forced through the nozzle and into the tuning pipe inlet.