Abstract: The pattern, composed of a polymeric material, is formed of three sections joined together by an adhesive along a pair of parallel parting lines. One parting line lies in a plane extending through the axis of an outlet to the engine block and through the axis of a sea water inlet, while the second parting line lies in a plane that extends through the axes of outlets leading to the exhaust manifolds of the V-engine. An inlet opening, through which coolant is received from the engine block, is located in one of the pattern sections and the axis of the inlet opening is normal to the parting lines.

Abstract: An evaporable foam pattern for casting a metal engine block for a two-cycle engine having a direct charge system. The pattern includes a block pattern section having a head end and a crankcase end and a plurality of cylinders extend between the ends. A transfer passage is associated with each cylinder and one end of each transfer passage communicates with the crank-case end of the block, while the opposite end of the transfer passage communicates with the cylinder adjacent the head end. The block pattern section is provided with a plurality of openings each of which provides communication between a transfer passage and the exterior and the openings are bordered by a generally planar surface. The pattern also includes a cover pattern section enclosing the openings in the first section.

Abstract: A tuned combustion air intake system for a rotary engine used in an outboard motor includes a plenum chamber mounted on the rear of the engine directly against the exhaust manifold, which plenum receives cooling air discharged from the engine. Air from the plenum chamber is directed into an elongated outlet conduit having an extended tuned length to provide an optimum pulsed air flow to the combustion air inlet of the engine. Direct attachment of the plenum chamber and integral outlet conduit to the rear of the engine eliminates extended length tubular connections of the prior art and allows the width of the engine to be kept to a minimum, thereby adapting the system to enclosure in a conventional cowl for an outboard motor.

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 for casting a metal block for a two-cycle engine. The pattern includes a first pattern section formed of a polymeric material and defining at least one cylinder. The first pattern section has a plurality of elongated slots each of which extends through the section and communicate with a cylinder. Each slot is bordered by an external planar surface. The pattern also includes a group of second pattern sections each formed of polymeric material and having an inner portion extending within a slot and having a peripheral flange disposed in abutting relation with the surface bordering the slot. The abutting surfaces are joined together by an adhesive.

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: An evaporable foam pattern assembly for casting a centrifugal pump housing for an internal combustion engine. The assembly comprises three pattern sections having abutting surfaces joined by adhesives along a pair of parting lines. The parting lines are parallel and disposed normal to the axis of the impeller chamber of the pump.

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 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: 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: An evaporable foam pattern for use in casting a metal part, such as an engine block. The pattern includes a first evapoable foam section having an outer peripheral rim and an internal wall which is spaced from the rim. The pattern also includes a second pattern section having a rim disposed in abutting engagement with the rim of the first section and having an internal wall spaced from the rim and disposed in abutting engagement with the internal wall of the first section. A third pattern section is disposed outwardly of said second section and has a rim disposed in abutting engagement with the rim of the second section. A layer of adhesive or glue is disposed between the abutting rims and between the abutting internal walls.

Abstract: A polystyrene foam pattern (10) is provided for the cylinder block of a crankcase compression two-cycle engine having transfer passages (15) formed in the block. The pattern includes a head-end component (12) and a crankcase end component (11) mating with each other. The mating surfaces extend through the transfer ports (14), transfer passages (15), and exhaust ports (16) to allow the formation of complex passages with die cast pattern components.

Abstract: The pattern comprises an engine block component having at least one generally cylindrical internal wall that defines a cylinder. A head encloses one end of the cylinder while the opposite end of the cylinder is open to the crankcase end of the block. One or more longitudinally extending recesses or cavities are formed in the cylinder wall. Each recess has a base portion spaced radially outward from the wall and a generally curved end spaced from the head. A separate evaporable foam strip or insert is secured across the recess and is spaced from the base portion to provide a longitudinal transfer passage, while an end of the insert is spaced from the curved end of the recess to define a transfer port that communicates with the cylinder. The longitudinal edges of the wall bordering the recess can diverge in a direction toward the axis of the cylinder, and the longitudinal edges of the insert are similarly contoured to mate with the edges of the wall. The mating edges are joined by an adhesive.

Abstract: In a two cycle internal combustion engine (2), the sidefaces (60, 62) of the connecting rod (40) have grooves (64) formed therein dragging lubricant from the fuel-air-lubricant mixture in the crankcase (8) along the crankfaces (38, 40) of the crankarm discs (34, 36) of the crankshaft (24), providing a hydrodynamic bearing with a layer of lubricant separating the sidefaces of the connecting rod from the crankfaces of the crankarm discs such that the sidefaces of the connecting rod ride on a layer of lubricant, and eliminating the need to silver plate the sidefaces of the connecting rod.