| 摘要 |
<p>A central direct injection (DI) cylinder head is configured with an intake valvetrain and an exhaust valvetrain separated by an uncovered central DI valley. The uncovered central DI valley limits oil flow from the high side chamber to the low side chamber and PCV transfer. Oil drainage and additional PCV transfer between the intake and exhaust chambers is provided by drain/vent passages integrally cast into the casting of the cylinder head. The drain/vent passages may be of varying configuration, and may be located between an injector port of a first cylinder set and a spark plug port of an adjacent cylinder set, or at either or both ends of the cylinder head. A method is provided to form a casting of the cylinder head as described herein, including casting of a plurality of drain/vent passages between the first chamber and the second chamber of the cylinder head.</p> |
