GB700364A - Improvements in or relating to cylinder heads for internal combustion engines - Google Patents

Abstract

700,364. Ports and passages. WESLAKE, H. Nov. 19, 1951 [Nov. 20, 1950], No. 28339/50. Class 7(2) In a cylinder head of the kind in which the roof of the combustion chamber 11, Fig. 1, is domed or of pent-house shape and in which are the inlet and exhaust ports 12, 13, respectively, and wherein the axis of each port is inclined to the longitudinal axis 14 of the cylinder, the former at a smaller angle than the latter, the inlet passage 16 as viewed along the axis 14 is so shaped and disposed that its axis, where it meets the plane of the inlet port 12, is at an angle to a radius from the axis 14 which intersects the inlet port axis in the said plane. The area ratio of the two ports 12 and 13 is either 4:3.5, the inlet port 12 being the larger, or 1:1; the inlet port 12 is arranged with one portion of its periphery adjacent the axis 14 whilst the exhaust port 13 is displaced from the axis 14 by 15 degrees so that one peripheral point is adjacent the joint surface of the cylinder head 10. The axes of the inlet and exhaust ports are at angles of 35 degrees and 43 degrees, respectively, to the axis 14. Both the inlet and exhaust passages 16, 18 are Venturi shaped and in plan view the longitudinal axes are curved and where they intersect the plane of the port they are oblique or inclined to a radius of the cylinder; the exhaust passage is of opposite obliquity to the inlet passage so that both passages converge. The sparking plug 24, Fig. 6, is arranged close to the cylinder axis 14. The mouth of the combustion space may either have two segmental shoulders, as shown in Fig. 6, or be of oval configuration with the major axis equal to the cylinder diameter and passing through the centres of the ports, or of circular form with a diameter less than that of the cylinder. In a modification, the combustion space is of pent-house shape and two inlet and two exhaust valves are provided in each cylinder, the area of the inclined surface 31, Fig. 3, in which are located the inlet ports 12, being greater than the other inclined surface 32 accommodating the exhaust ports 13; the junction 33 of surfaces 31 and 32 is on one side of the axis 14. The inclination of surfaces 31 and 32 is such that the axis of the inlet and exhaust ports are arranged at angles of 35 degrees and 44 degrees, respectively, to axis 14, whilst the inlet passages 16, Fig. 4, have their axes, as viewed in plan, inclined to a radius extending between the ports where the axes intersect the plane of the ports, so as to promote swirling of the charge. The corresponding axes of the exhaust passages 18 are parallel to one another and to a radius extending between the ports. When a single exhaust passage is provided with a pent-house shaped combustion chamber, the passage axis, as viewed in plan, may be either oblique or parallel to a cylinder radius meeting the plane of the exhaust port. Specification 610,114 is referred to in the Provisional Specification.