Yamaha Hatsudoki Kabushiki Kaisha

Junkichi Amano

Takashi Hara

Tetsuji Yamazaki

Masaaki Yoshikawa

Shuhei Adachi

Masatoshi Ohmi

Hiroyuki Sakai

Yoichi Onishi

Minoru Yonezwa

Masashi Murakami

An induction system for an internal combustion engine having at least one intake passage that is configured to generate a tumble and swirl to the intake charge. This is accomplished by providing a masked section adjacent the valve seat so that the flow entering the combustion chamber is directed across the combustion chamber to generate the tumble action. There is also provided a secondary intake passage that delivers a charge to the combustion chamber in a substantially unrestricted fashion so as to permit high power outputs. The secondary intake passage has the flow through it controlled by a throttle valve that is closed under low and mid-range running conditions.

Induction system for engine

A method of forming cylinder heads having bonded valve seat inserts. The method reduces the machining operations necessary to place the insert in place by forming the cylinder head casting with reference surfaces that are employed for determining the pressing axis and location for the valve seat insert.

Method for forming valve seats

A cylinder head and valve seat arrangement wherein insert rings are metallurgically bonded to the base material of the cylinder head. This permits large valve sizes and multiple valve construction without the likelihood of failures.

Valve seat and method

An improved cylinder head cooling arrangement for use in multiple valve internal combustion engines wherein the coolant exits the cylinder head through primarily a single exit passage formed in the lower cylinder head surface beneath a manifold section of the cooling jacket that extends beneath the multiple exhaust passages.

Cylinder head cooling structure for multi-valve engine

Several embodiments of V type internal combustion engines having multiple valves per cylinder and an overall compact arrangement. This is achieved by employing only a single camshaft for operating all of the valves of each cylinder head and the axis of rotation of the camshafts is offset toward the valley side of the cylinder head. Various valve arrangements are disclosed in operating mechanisms.

Automobile engine structure

A number of embodiments of compact high efficiency induction systems for an internal combustion engine. In each embodiment, the induction system includes a first pipe section that extends from the respective intake passage of the engine and which terminates in a downwardly turned right angle section. A U shaped pipe section is interconnected at one end to this right angle section and its other end is served by a plenum chamber that is integrally formed with the first pipe section. In some embodiments, the plenum chamber lies at least in part over the first pipe section and in other embodiments it is forwardly of it. In some embodiments, the U shaped pipe section is detachably connected to the plenum chamber, first pipe section assembly so as to permit attachment of different length sections for tuning for different engines.

Air intake device for an engine

A lubricating system for an internal combustion engine including an improved lubricant return for returning lubricant from the valve actuating mechanism of the cylinder head to the crankcase.

Oil return system for overhead cam engine

An internal combustion engine having an improved cylinder head draining arrangement for accumulating oil that may leak from the cylinder head and its cover in use or which may flow from the cylinder head when the cover is removed for surfacing. The drain trough is inclined and has a drain opening at its lowermost end in which a removable closure plug is positioned.

Growing community of inventors

Iwata, Japan

Junkichi Amano