Marine engine

Claim 1

In an internal-combustion engine of the type including: a cylinder block, first and second banks of cylinders is said block, said banks being upwardly and outwardly inclined, a pair of cylinder heads secured to said block, a cover extending across and sealed to said cylinder heads and cylinder block, whereby a compartment is formed between said cylinder heads by the cylinder heads, cylinder block, and cover, a crank case at the lower portion of said cylinder block, and passage means between said compartment and said crank case, the improvement comprising: a centrally feeding manifold mounted in said compartment centrally of said cylinders and having an entrance in the top thereof, a downdraft carburetor mounted on top of said manifold and connected to the entrance of said intake manifold, said downdraft carburetor having a vertical passageway for flow of air through a top opening downwardly into said entrance of said intake manifold, said separately feeding manifold being separate from said cylinder block, said cylinder heads being secured to said cylinder block over said manifold to hold said separate manifold on said cylinder block solely by the clamping of said heads to said block, an annular extension surrounding an opening on said cover above said carburetor, said annular extension and said carburetor forming an annular passageway, and a cover for said carburetor positioned above said annular extension to provide an opening between said annular extension and said cover for flow of air inwardly to and downwardly through said carburetor, said flow of air applying by eductive effect a negative pressure to said annular passageway which acts through said passAge means to provide positive crank case ventilation.