Head for high performance internal combustion engine

Claim 1

In a cast head for an high performance internal combustion engine of the type using an atomized mixture of air and liquid fuel, said head including a flat mounting surface and having, for each of several in-line circular piston areas, (a) a wedge type combustion chamber extending from a head mounting surface and defined by a flat quenching surface coplanar with said mounting surface and extending generally along a chord of said circular piston area, and a concave, contoured wedge-shaped cavity forming surface, said wedge-shaped cavity tapering outwardly from said quenching surface between a shallow chordal area adjacent said quenching surface and a deeper valving area removed from said quenching surface; (b) a circular exhaust valve seat defining an exhaust outlet at said deeper valving surface and having a first axis; (c) a circular intake valve seat defining an intake inlet at said deeper valving surface and having a second axis; (d) an exhaust passage extending from said exhaust outlet with a first passage portion extending generally axially of said first axis and a second elongated outlet passage portion with a general axial centerline forming a first angle with said first axis; (e) an intake passage extending to said intake inlet with a first passage portion extending generally axially of said second axis and a second elongated inlet passage portion with a general axial centerline forming a second angle with said second axis for introduction of an atomized mixture of air and fuel into said combustion chamber through said intake inlet; and, (f) a spark plug receiving bore in said cavity forming surface generally between said first and second axes, an improvement for obtaining, at 5000 RPM, a brake specific fuel consumption of substantially below 0.50 Lbs/BHp-Hr and a brake horsepower of over 400 Hp, said improvement comprising: (g) said first and second axes being located adjacent a diameter defined by said circular piston area and on a line generally parallel with said chord of said quenching surface; (h) said valve seats being at an angle of less than about 15° from said flat quenching surface whereby said first and second axes are at an angle of less than about 15° from said quenching surface and the lower end of said intake valve seat being spaced vertically from said flat quenching surface only a slight distance; (i) said cavity forming surface at said deeper area having the general contour of two parallel intersecting, truncated cones generally concentric to said first and second axes with a gradually contoured surface section between said cones at the deeper valving area of said cavity forming said combustion chamber; (j) a velocity increasing protuberance in said combustion chamber at said shallow chordal area of said cavity, said protuberance including an edge portion, said edge portion further defined by a first and second arcuate portion generally concentric with said first and second axes, respectively, and a continuously smoothly curved intermediate edge portion inbetween said first and second edge portions extending in an inwardly concave direction into said chamber; and, (k) said cavity forming surface adjacent said intermediate edge portion and between the peripheral portions of said intake and exhaust valve seats which are facing one another further defined by an inwardly, generally smoothly curved convex surface adjacent said intermediate edge portion blending into an inwardly concave surface adjacent said peripherally facing portions of said intake and said exhaust valve seats to provide for an improved gas mixture and exhaust mixture flow past said seats without detrimental turbulence.