Abstract: A V-type cylinder block of internal combustion engine is disclosed, which provides two angularly disposed cylinder banks each having a cylinder row of cylinders. A plurality of ribs rise generally from head bolt hole portions defined between two cylinders adjacent each other, are provided between two cylinder rows for interconnecting wall portions of the cylinder rows and intersect at the middle of the cylinder rows for forming intersecting points. At the intersecting points of the plurality of ribs are disposed fixing portions of knocking sensors for detecting an engine knocking.

Abstract: A power transmission apparatus has a first shaft and a second shaft which are supported by an aluminum housing, and an iron gear and a synthetic resin gear which are respectively mounted on the two shafts and are engaged with each other. The synthetic resin used for the synthetic resin gear contains an aromatic polyamide fiber.

Abstract: An engine block comprising a first crankcase-defining member including a first semi-cylindrical surface having an end and extending about a first center, and also including a first shoulder extending radially outwardly from the end of the first semi-cylindrical surface, a second crankcase-defining member fixedly connected to the first crankcase-defining member and including a second semi-cylindrical surface located in generally co-planar facing relation to the first semi-cylindrical surface having an end and extending about a second center located in spaced relation to the first center, and also including a second shoulder extending radially outwardly from the end of the second semi-cylindrical surface, a crankshaft supported by the engine block and including a crankcase-defining disc including a cylindrical surface in spaced and generally co-planar facing relation to the first and second semi-cylindrical surfaces and including therein an annular groove, a first seal member located in the annular groove and h

Abstract: The oilpan of a low-noise crankcase is bolted to the downwardly extending ankcase sidewalls and has omega-shaped crosspieces extending transversely to the oilpan sidewalls and to the sidewalls of the crankcase, and the crosspieces are in alignment with the main bearing walls of the crankcase. The crosspieces form part of the oilpan and are connected to its sidewalls in such a manner that forces are propagated, the sidewalls being reinforced as compared to the bottom of the oilpan which is not reinforced. The oilpan is bolted to the crankcase by additional bolts located in pockets in the crosspieces on both sides of the cylinder axes, and are attached to the crankcase as far away from the outer walls thereof as possible.

Abstract: A one-piece crankcase and cylinder block structure for V-type internal combustion engines is disclosed, which is formed by casing and comprises a crankcase with its one end wall side opened and a cylinder block including at least a pair of right and left cylinders opposed to each other at 90.degree.. The cylinders are formed to project at their skirt portion into inside of the crankcase forming a longitudinal space between the protruded ends of the skirt portions to house a camshaft. Another space is defined adjacent to the opened side of the crankcase between the protruded ends of the skirt portions to house a camshaft gear. Since the construction is such that, in casting, the directions in which the segments of mold and the cores are ejected from the casting are uniformly distributed, and the distance over which the cores and mold segments are ejected is greatly minimized. Thus, a relatively small casting machine can be employed to properly cast such a one-piece crankcase and cylinder block structure.

Abstract: The present invention provides for an internal combuston engine having housing parts such as a cylinder, cylinder head and crankcase formed of a light metal. A plurality of tightening screws are provided for securing the above-mentioned parts so as to form an engine block, the screws having threaded ends which are received in the heads of steel tie rods which are integral with the crankcase and which extend substantially parallel to the cylinder axis. When the engine is in use, the tightening of the light metal housing parts by way of the steel tie rods, prevents undesired deformation of the crankcase.

Abstract: Components in or for self-powered vehicles, including in particular an integrated power unit in which a reciprocating-piston internal combustion engine and a transmission system are formed as a compact, single structural item in which the engine cylinders and the principal rotary members of the transmission are all located to one side of a plane which lies normal to the cylinder axes and includes the engine crankshaft axis. Compactness and simplicity are further promoted by designing the casing structure of the power unit to include an indivisible main component which encases parts of both the engine and the transmission system. The invention also includes features combined with and/or related to such a power unit, including a specific design for the transmission system, an arrangement of the induction system for the engine, installation arrangements for the power unit within vehicles, and related vehicle suspension systems.

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 portable engine unit is provided. The unit comprises an engine including a clutch, a crankcase enclosing a crank shaft, an engine cylinder enclosing a piston and a piston rod, a carburetor, an air filter, a recoil starter, and a muffler; and a housing for enclosing the engine, comprising at least two portions which are assembled and disassembled along a plane including the axis of rotation of an output shaft of the engine to enclose and expose the engine.

Abstract: A portable engine has a fan cover fixed to a front surface of a crankcase to cover a fan and to guide upward a blown stream of air generated by the fan, and a cylinder cover disposed behind and in series with the fan cover to cover an engine cylinder and to guide the blown stream toward the engine cylinder. The portable engine has a partition plate formed integrally with said crankcase to cover a step formed between the fan cover and the cylinder cover, and an ignition coil is fixed to the partition plate. According to this arrangement, heat of the engine cylinder will not be directly transmitted to the ignition coil to cause deterioration of the function of the ignition coil. The engine cylinder has positioning pieces which are engaged with positioning holes formed on the crankcase to allow easy assembling and a correct positioning of the engine cylinder and the crankcase.

Abstract: Components in or for self-powered vehicles, including in particular an integrated power unit in which a reciprocating-piston internal combustion engine and a item in which the engine cylinders and the principal rotary plane which lies normal to the cylinder axes and includes the engine crankshaft axis. Compactness and simplicity are further promoted by designing the casing structure of the power unit to include an indivisible main component which encases parts of both the engine and the transmission system. The invention also includes features combined with and/or related to such a power unit, including a specific design for the transmission system, an arrangement of the induction system for the engine, installation arrangements for the power unit within vehicles, and related vehicle suspension systems.

Abstract: An engine cylinder block structure includes: a cylinder block integrally formed to include skirts projecting downwardly from both sides of the lower surface of the cylinder block; an oil pan attached to lower surfaces of both skirts of the cylinder block, the oil pan having a deep first portion on a front side and a shallow second portion on a rear side, the first and second portions being connected to each other; flanges integrally formed on lower ends of the skirts for having the oil pan attached thereto; and reinforcing mechanism for reinforcing the strength of both skirts.

Abstract: A chain saw has an intermediate wall portion integrally formed with a body thereof for separating an internal combustion engine chamber from a carbureter chamber and a fuel tank chamber. The intermediate wall portion includes a double wall portion having a heat insulation space formed therein, and an opening portion through which the carbureter chamber communicates with the internal combustion engine chamber, the opening portion forming a seat for mounting the carbureter.

Abstract: This invention relates to an internal combustion engine including an oil seal ring between a cylinder block and a crank shaft, a crank shaft cap and a conduit. The cylinder block includes a plurality of cylinders, a crank shaft support portion and an oil seal retainer. The crank shaft support portion is located under the plurality of cylinders and the oil seal retainer projects outwardly from the cylinder block. A crank case is defined within the cylinder block. The crank shaft cap is secured to the crank shaft support portion and an opening is defined therebetween. The crank shaft includes a main journal and a flange portion. The main journal is inserted into the opening defined between the crank shaft support portion and the crank shaft cap. The crank shaft is rotatably mounted on both the cylinder block and the crank shaft cap.

Abstract: A crankshaft supporting structure in a multicylinder internal combustion engine has a cylinder block made of a light alloy and including a cylinder housing and a crankcase having a plurality of spaced journal walls. A plurality of spaced bearing caps made of an iron alloy are coupled respectively to the journal walls. A crankshaft is rotatably supported in bearing holes defined by the journal walls and the bearing caps. A bridge made of a light alloy extends across the bearing caps and is coupled to the bearing caps. The bearing caps and the bridge are fastened together to the journal walls by connecting bolts disposed one on each side of the crankshaft. The bridge has a main portion defining a main gallery extending longitudinally therethrough and a plurality of legs coupled to the bearing caps, respectively. The bearing caps and the legs jointly define branch oil passages communicating with the main gallery and the bearing holes.

Abstract: An internal combustion engine for motor vehicles in which the main journals for the crankshaft are rotatably supported by main bearings including upper portions fixed to the engine block and lower caps joined to the upper portions by pairs of tie-rods anchored at one end to the cylinder head and interconnected at their opposite ends by respective brackets which surround and clamp the caps against the upper portions of the respective main bearings.

Abstract: In an internal combustion engine, the cylinder head 1 is screw-fastened to the cylinder crank case 2 by means of differential screws 8, each of which has two threaded sections 11 and 12, of which section 11 has a larger outside diameter and a smaller pitch than the second section 12. The threaded sections 11 and 12 cooperate with corresponding internal threads 13 or 10 in the cylinder head 1 or in the cylinder crank case 2. As a result of the different pitches of the two threaded sections 11 and 12, there occurs a joint tensioning of the cylinder head 1 with the cylinder crank case 2, without a bearing surface for a screw head or a nut being required. The space requirement for the cylinder head fastening thereby becomes exceptionally small, so that the fastening can be provided at points, for example, between adjacent valves, at which no space would otherwise be available for a bearing surface for screw heads or nuts.

Abstract: A crankshaft support structure for a multicylinder internal combustion engine employing a plurality of bearihng caps with pairs of vertical and horizontal surfaces fitting mating surfaces in the cylinder block for structurally mating the bearing caps to the cylinder block. A structural bridge extends across the bearing caps and is connected through the bearing caps to the block by one set of bolts and directly to the block by a second set of bolts. A second embodiment employs a third set of bolts connecting the bearing caps separately to the block. Arcuate baffle plates form the portion of the bridge between bearing caps to inhibit oil agitation and suppress noise.

Abstract: A lightweight composite cylinder housing is provided to decrease fuel consumption, attenuate noise, and permit increased speed of operation.

Abstract: A crankshaft support for a multicylinder internal combustion engine employing a plurality of bearing caps fitted in recesses in journal walls in the cylinder block and connected by pairs of bolts extending vertically through each bearing cap into the journal wall. An additional pair of bolts extend horizontally from each side of the cylinder block to connect the skirt portions to the bearing caps. A bridge extends the length the engine over the bearing caps and is connected thereto by another pair of vertical bolts.

Abstract: A motorcycle having an improved engine construction wherein the combined crankcase transmission assembly of the power plant is formed from upper and lower members that have mating faces that lie in a plane that is disposed at a downwardly extending angle in a forward direction to the horizontal. A cylinder block having a plurality of transversely spaced cylinder bores is affixed to the forward end of the upper member of the main casing and has the cylinder bores inclined at a forwardly extending angle to the vertical.

Abstract: A two cycle engine having multiple cylinders which is capable of expanding from two or four or more cylinders. A composite crankshaft is built up by combining components including crank webs, bearing shafts and crank pins. A composite crankcase also may expand to accommodate the number of cylinders required through the use of common mating surfaces. The mating surfaces provide opposed thrust surfaces for each pair of crank pins.

Abstract: A cylinder block structure of a light alloy for use in a multicylinder internal combustion engine includes a cylinder-defining portion having a plurality of cylinder bores with a water jacket defined in surrounding relation to the cylinder bores, and a crankcase-defining portion integrally formed with the cylinder-defining portion and having a plurality of integral journal walls spaced in the direction in which the cylinder bores are arranged. Concavities are defined in opposite sides of the cylinder- and crankcase-defining portions between the adjacent cylinder bores, the concavities lying between the water jacket and journal walls. A plurality of reinforcing rib systems project from the opposite sides of the cylinder block and each rib system surrounds one of the concavities. The concavities reduce the amount of molten metal to be poured in casting the cylinder block structure, for thereby preventing casting defects such as cavities from being produced in the cylinder block.

Abstract: A marine propulsion device comprising a lower unit including a rotatably mounted propeller, and an internal combustion engine drivingly connected to the propeller, the engine including an engine block, a crankshaft rotatably supported by the engine block and including an end portion projecting from the engine block, a flywheel including a hub, the hub being mounted on the end portion of the crankshaft and having an outer surface, and a bearing located between the engine block and the outer surface of the flywheel hub for facilitating rotation of the flywheel relative to the engine block.

Abstract: A motor-driven chain saw essentially includes a housing having a rear handle and a front handle and a drive unit attached to the housing. A guide bar for accommodating the saw chain for movement thereon is attached to the drive unit. The housing has an extension arm on the underside of the chain saw which extends to the front; the drive unit is seated on this arm and the front handle is attached to the front end of the arm. To increase torsional and bending strength, the extension arm has an S-shaped profile when viewed in cross section. The S-shaped profile has a substantially rectangular configuration and includes lower, middle and upper parts that are parallel to one another and are interconnected by two flanks. The flanks are located in planes that are parallel to the guide bar.

Abstract: These crankshaft bearings consist of a light-metal alloy and are formed by a bearing section of a crankcase and a bearing cap. In order to avoid a bearing clearance causing noise, a core made of iron metal is poured at least into the bearing cap, said core, by means of a bearing area, directly surrounding the crankshaft journal of a crankshaft, and having lugs for bores connected by a transverse part. The bores are penetrated by the screws in order to fasten the bearing.

Abstract: An improved crankcase structure and manufacturing method for engine blocks and the like wherein the crankcase is initially cast or otherwise formed with bearing caps integral therewith. The caps are preferably secured by severable connecting portions unidirectionally longitudinally adjacent their associated bearing receiving portions in the transverse webs of the cylinder block. The complete crankcase is then machined and the bearing caps are separated for subsequent assembly to the crankcase in conventional fashion. The invention reduces the amount of tooling and machining time and equipment required for manufacturing crankcases for engine blocks and the like.

Abstract: An arrangement for mounting a two-stroke cycle vertical crankshaft internal combustion engine on a rotary mower deck to accept a four-stroke cycle vertical crankshaft internal combustion engine whereby either type engine may be adapted to the same mower deck is disclosed including a feature for minimizing the risk of crankshaft or crankcase damage in the event of impact of the rotating mower blade with a relatively immovable object. By employing the adapted which allows mounting of the two-stroke cycle engine on the mower deck to also reinforce the lower region of the engine crankcase where the crankshaft extends from the crankcase a lighter weight, cheaper construction of the two-stroke cycle engine is possible.

Abstract: An internal combustion V-type engine has a crankcase which is split horizontally on a plane containing the axis of the crankshaft. Relatively thin stationary webs in the upper and lower crankcase halves are aligned and each pair receives a plurality of fastening elements such as cap screws which extend through the lower half of the crankcase across the horizontal joint and into the upper half of the crankcase. These pairs of webs are placed at intervals along the length of the crankshaft to support it for rotation.

Abstract: Each cylinder of a liquid cooled in-line internal combustion engine includes a cylinder pipe surrounded by an annular cooling chamber. The cooling chambers are interconnected in series by crossover passages between adjacent cylinder pipes and the cooling chambers have a greater cross sectional flow area on one side of the longitudinal central plane of the engine than on the other side. This cross sectional flow area relationship is reversed from cylinder to cylinder to thereby cause a meandering course of flow for a portion of the coolant thereby assuring adequate flow around the entire surface of the cylinder pipe and good flushing of the crossover passages between the cylinder pipes.

Abstract: The invention relates to a Diesel engine in which there is obtained a very low permanent magnetic signature by embodying some of its component parts with high volume/mass ratio in a magnetic material, and by reducing or annulling the permanent magnetism of its component parts which are for constructional reasons made of magnetic material by individual demagnetization treatment.

Abstract: A motor vehicle having a rotary piston engine located at a front part of the vehicle with the engine output shaft extending in a longitudinal direction of the vehicle. A speed changing transmission and a center differential gear unit are arranged in this order from the engine so that the center differential gear unit drives the rear propeller shaft and the front differential gear unit. The front differential gear unit is located beneath the engine and driven through a transfer shaft by the center differential gear unit. The front differential gear unit is mounted on the oil pan of the engine which is attached to the lower part of the engine casing.

Abstract: The problem of cracking in scantlings of aluminium or aluminium alloy engine blocks by direct and torsional forces applied thereto by a crankshaft is mitigated by casting, into the scantlings, reinforcements of a ferrous material. Each reinforcement includes threaded bosses for receiving the bolts which hold an associated cap onto the scantling and also flat elongate members which extend into the scantling. Since the threads are of a ferrous material, they are more resistant to damage than similar threads of aluminium or aluminium alloy and the elongate members spread the loading throughout the scantling, so reducing the tendency of these loads to crack the scantling. This technique can be of particular benefit where an engine is being modified in a way which produces increased stresses; for example where a petrol engine is being converted for use as a diesel engine.

Abstract: A motorcycle has a V type engine with its cylinders inclined other than vertically or horizontally, with a crankshaft extending transversely on the cylinders lying in a forwardly-directed vertical plane. A transmission is mounted to the motorcycle rearwardly of the engine, and has a main shaft adjacent to the crankshaft with its axis rearwardly of and at an elevation beneath the axis of the crankshaft. Stud bolts screw into the crankcase, the arrangement of the shafts enabling the wall thickness of the crankcase to be locally increased to provide for sufficient strength of threads without creating interference with the gears on the main shaft.

Abstract: An internal combustion engine has an integral cylinder block, crankcase and sump structure made in two halves 1, 2. The material of the halves is chosen for lightness. The pressure pulsations in the cylinders are taken by long steel bolts 14, 15 which extend from the top of the cylinder head to a bearing structure comprising yokes (steel clamping members 8, 9 clamped together by traverse fasteners 12, 13) holding together the two main crankshaft bearing housing halves 6, 7 which are formed integrally with each half of the integral engine structure. The integral halves do not have re-entrants and can be produced simply by casting, pressing or moulding.

Abstract: In a cylinder block for an internal combustion engine, a pair of opposed side walls thereof extending in the direction of the row of cylinders therein are respectively formed of a plurality of bight portions. The bight portions in each side wall differ in phase from those in the other side wall.

Abstract: There is disclosed a lubricant feed system for use in a journal of a crankshaft comprising first bearing supporting portions formed in a cylinder block, each having a peripheral surface, second bearing supporting portions formed in caps, each having a peripheral surface, first bearings in the form of half shells arranged on the peripheral surfaces of the first bearing supporting portions, second bearings in the form of half shells arranged on the peripheral surfaces of the second bearing supporting portions and an oil main gallery. In this arrangement, annular grooves are formed on the peripheral surfaces of the first and second bearing supporting portions and oil grooves are circumferentially formed at the inner peripheral surfaces of the first bearings. Apertures are formed at the first bearings to communicate the annular grooves with the oil grooves. The inner peripheral surfaces of the second bearings are made flat.

Abstract: A crankcase assembly for the engine of a portable tool such as chain saw or the like is disclosed. A plastic crankcase is connected to the cylinder of the engine and an annular insulating member is mounted between the cylinder and the crankcase. The annular insulating member is made of a firm temperature-resistant plastic thereby protecting the crankcase from the temperature developed in the cylinder during the operation of the engine.

Abstract: A portable tool such as a motor-driven chain saw is disclosed which includes a cylinder, a piston, a connecting rod and a crankshaft. The crankshaft is rotatably journalled in crankshaft bearings and a crankcase made of plastic is provided. The bearing shells of the crankshaft bearings are releasably connected only to the cylinder and independently of the plastic crankcase. The plastic crankcase is likewise attached to the cylinder in such a manner that a housing arrangement is provided which is free of transmitted forces and is fully independent of the crankshaft bearings.

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 motor mount having first and second mounting surfaces with at least three mounting elements fixed therebetween is used to absorb motor vibration and shock impulses which are produced primarily parallel with the plane of the mounting surfaces. Two of the three mounting elements are dampers which flexibly connect the first mounting surface in a parallel relation with the second mounting surface. The third mounting element maintains a preferred range of distance separation between the mounting surfaces to that a damping flexion potential of the dampers is maintained.

Abstract: A lawn mower comprising a blade housing, an internal combustion engine being supported on the blade housing and including a crankshaft, an output shaft rotatably supported by the blade housing, the output shaft being operably connected to the crankshaft such that rotation of the crankshaft at a given rpm causes rotation of the output shaft at an rpm less than the rpm of the crankshaft, and the output shaft having a cutting blade fixedly mounted thereon and housed within the blade housing.

Abstract: A cylinder block comprises an upper section having a plurality of engine cylinder bores therein, the upper section having first and second oppositely disposed wall members, and a skirt section having a cavity defining a crankcase for an engine crankshaft, the skirt section having first and second oppositely disposed walls which are integral to and in straight alignment with the first and second wall members of the upper section, respectively, thereby effectively preventing noise radiation from the skirt section and improving the torsional and flexural rigidities of the cylinder block.

Abstract: A crankcase having a unitary transverse bearing wall through which a crankshaft is mounted. The bearing wall includes blind holes extending passed the bearing hole on either side thereof for receipt of high strength bolts extending therein.

Abstract: Disclosed herein is a method of fabricating an integrally cast engine block including a plurality of cylinders, exhaust passage portions which respectively extend from the cylinders and which form portions of exhaust gas passages of equal length, and a water jacket cavity including respective water jacket cavity portions in encircling relation to the exhaust passage portions, which method comprises the steps of providing a mold cavity which defines the exterior surface of the block, locating one or more disposable cores in the mold cavity so as to provide for the exhaust passage portions and for the water jacket cavity, filling the mold cavity with molten metal to provide a unitarily cast engine block, permitting soldification of the block with the cores contained therein, and removing the disposable cores from within the engine block to provide the hollow exhaust passage portions and the water jacket cavity.

Abstract: The crankshaft of an internal combustion engine is supported in a split bearing assembly near one end of the crankshaft, with the lower half of the bearing assembly formed in a bearing holder secured to the engine block. An arcuate flange projects axially towards that end of the crankshaft. The flange underlies a crankshaft pulley which drives a timing belt. The arcuate surface of the flange is struck from a center offset from the crankshaft axis in order to provide clearance for the timing belt. The offset construction also improves the joint seal between the oil pan and the engine block.

Abstract: A pump for lubricating oil is mounted on the outer face of the end wall of an internal combustion engine. An oil filter is mounted on a side wall of the engine parallel to the crankshaft, and a substantially straight sub-gallery in the side wall connects the oil pump to the oil filter. A substantially main gallery receives lubricating oil from the oil filter and delivers it to branched oil supply passages to lubricate parts of the engine.

Abstract: Arrangement for inserting a spark plug in a V-type engine cylinder head, comprising a separate sleeve surrounding the spark plug and removably insertable in the wall of the combustion chamber by screw threading. The spark plug extends through the cam chain chamber and can be removed without interference with the operation of the endless cam chain.

Abstract: To service an engine, it is frequently determined that a cylinder liner and piston must be replaced. Removal is difficult and time consuming if the piston is first removed through the liner and the liner is then grasped from below and pulled from the block. A method includes inserting a tool into a bore of the liner and expanding the tool into a frictional fit against the liner. A force is applied on the tool to forcibly move the liner. The piston and associated rings and rod are held in place in the liner by a partial vacuum for removal with the liner as a complete unit.

Abstract: A small internal combustion engine especially--but not exclusively--for model aircraft is made at an extremely low cost. A crankcase and a fuel tank are made of two casted pieceparts which nest together. The two pieceparts include matching openings which are aligned to provide an air intake and a manifold leading from the fuel tank into the interior of the crankcase. A crankshaft is journaled to rotate within the crankcase. A connecting rod is made from a generally "Y" shaped leaf spring. The stem of the "Y" is mounted on a throw on the crankshaft for producing a reciprocal motion within a cylinder. The tops of the "Y" shaped connecting rod are shaped to form diametrically opposed dimples. A cup-shaped piston has diametrically opposed, internal abuttments formed by a hole drilled through the piston skirt. The dimples on the connecting rod snap into the opposing holes inside the piston.