Patent ID: 9650937
Date: 2017-05-16
CPC Classifications: F01N,F01P,Y02T

Claim:
1. An outboard marine engine comprising: an engine having a cylinder block having a plurality of vertically-aligned cylinders; an exhaust manifold configured to convey exhaust gases from the engine, wherein the exhaust manifold comprises a plurality of vertically-aligned exhaust runners configured to horizontally convey the exhaust gases from the engine, and a first exhaust passage configured to vertically upwardly convey the exhaust gases from the plurality of vertically-aligned exhaust runners; a cooling water jacket on the exhaust manifold, the cooling water jacket being configured to convey cooling water alongside and in thermal communication with the exhaust manifold; and a cooling water pump configured to pump the cooling water through the cooling water jacket and particularly vertically downwardly alongside the first exhaust passage; wherein alongside the first exhaust passage, the cooling water jacket defines a converging passageway that converges from a vertically higher portion to a vertically lower portion so that as the cooling water flows vertically downwardly through the converging passageway, air pockets within the cooling water tend to exit the cooling water via buoyancy or and drag due to flow velocity.