Abstract: An internal combustion engine includes a cylinder head having attachment surfaces which lie in the same plane and to which a head cover and an intake manifold are attached, respectively. The attachment surfaces can therefore be machined simultaneously in one process with a common cutting tool. The internal combustion engine also has a valve operating mechanism housed in a valve mechanism chamber in the cylinder head for actuating intake and exhaust valves. The valve mechanism chamber is defined by a pair of opposite trapezoidal end walls extending from the bottom of the valve mechanism chamber and a ceiling wall integrally interconnecting the upper ends of the trapezoidal end walls. The valve mechanism chamber has a pair of windows defined one on each side of the ceiling wall thereof between the trapezoidal end walls to provide access therethrough to the valve operating mechanism.

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: An intake manifold for an internal combustion engine wherein individual intake passages communicate between an air distribution chamber and each engine cylinder. Separate bypass passages extend from the distribution chamber and each intake passage at a downstream location to provide a substantially shorter effective passage to the engine cylinders and a valve in each bypass passage is operated in response to engine speed to open the bypass passages at high engine speeds.

Abstract: An air intake system for an internal combustion engine wherein the intake port to a combustion cylinder is connected to a trunk portion of the intake system which contains the throttle valve. A high speed intake passage of a relatively short length and a slow speed intake passage of a relatively long length are both connected to the trunk portion with a control valve in the high speed intake passage. The control valve is opened for high speed operation of the engine and closed for slow speed operation to operatively select between the two intake passages. In modified embodiments the degree of opening of the control valve is modulated in proportion to the r.p.m. of the engine.

Abstract: A DOHC engine of the V-type has two cylinder heads each detachably secured to a cylinder block. A crank shaft on the block drives two intermediate shafts, one on each cylinder head, by means of an endless flexible element. An additional flexible endless element is provided in each cylinder head to drive two cam shafts from the intermediate shaft on that cylinder head. Each endless flexible element together with its toothed pulleys or sprockets and its timing belt or chain is described as a wrap-around transmission.

Abstract: The present invention discloses an internal combustion engine having an auxiliary combustion chamber in which a principal chamber is provided having (a) two intake valves and an intake port connected thereto and, (b) on the opposite side of a vertical plane extending along an axial line centered at the crank shaft and the center of the cylinder, a single exhaust valve and an exhaust port connected thereto, the same being in communication with the auxiliary combustion chamber.