Mazda Motor Corporation

Masahiro Choushi

Haruyoshi Ishimi

Tetsuji Yahiro

Shin Hiraoka

A V-type engine construction which comprises an engine block having a pair of upwardly diverging cylinder banks with a generally V-shaped space defined therebetween and also having a plurality of engine cylinders defined in each of the cylinder banks, generally rectangular cylinder heads of identical shape adapted to be mounted on the respective cylinder banks, each of which cylinder heads has intake ports communicateable with the respective engine cylinders in the associated cylinder bank and defined therein so as to open generally towards the V-shaped space and also has two spaced coolant outflow ports which are in located adjacent front and rear ends of the respective cylinder head with respect to the direction of arrangement of the engine cylinders in the associated bank and are defined therein so as to open generally towards the V-shaped space, and an intake manifold integrally formed with lids one for each cylinder head, each of which lids is adapted to close one of the outflow ports in the associated cylinder head when the intake manifold is mounted on the cylinder heads.

Engine construction

A V-type engine having a pair of cylinder banks set at an angle to each other is provided with a plurality of separate intake passages, each for one cylinder. The intake passages have respective proximate portions at which the intake passages to the cylinders in one cylinder bank and those to the cylinders in the other cylinder bank are in proximity or aligned with each other as viewed in the direction of the crankshaft. An exhaust recirculation passage for recirculating exhaust gas from the exhaust passage to the cylinders extends along the proximate portions in the direction of the crankshaft and is communicated with each intake passage by way of a communicating hole.

Exhaust gas recirculation system for a V-type engine

A V-type overhead-camshaft engine comprises first and second banks arranged in V-shape, each bank having a row of a plurality of cylinders extending axially between front and rear ends thereof. The row of the cylinders in the first bank starts from a location spaced apart from the front end of the engine, and terminates at a location near the rear end of the same. The row of the cylinders in the second bank starts from a location near the front end of the engine and terminates at a location spaced apart from the rear end of the same. Each bank is provided with a cylinder head assembly which generally comprises a cylinder head and a head cover, and supports a camshaft. The cylinder head assembly of the first bank is provided with an opening at a location corresponding to the part of the bank between the front end of the engine and the foremost cylinder in the first bank, while the cylinder head assembly of the second bank is provided with an opening at a location corresponding to the part of the second bank between the rear end of the engine and the rearmost cylinder in the second bank. The openings in the cylinder head assemblies of the first and second banks are identical to each other and are located symmetrically with respect to the center of the engine. One of the openings is used as an oil filler section, and the other opening is used as an engine auxiliary mechanism mounting section.

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Hiroshima, Japan

Masahiro Choushi