an increase in displacement to 2.0 L. The slant-four was also used by Panther in the Dolomite-based Rio (1975–1977). The TR7 debuted in 1975 with the 2.0 L engine and 8-valve cylinder head. A few pre-production TR7 Sprint models received the sportier Sprint engine in 1977. Triumph stopped producing the slant-four when the TR7 was discontinued in 1981. The V8 member of the engine family first appeared in a Triumph vehicle in 1970, fully two years before the slant-four. Development of the V8 had continued throughout the mid- to late-1960s, with early engines displacing 2.5 L. When Charles Spencer (Spen) King took over as Head of Engineering from Webster, he authorized continued development of the Triumph V8, and was also instrumental in getting the car it powered, the Triumph Stag, into production. The production V8 displaced 3.0 L. Technical features The slant-four's engine block is of cast iron (called chrome iron in some references). The cylinders are inclined at an angle of 45° from vertical. This allowed the engine to be built with the same tooling needed for a V8, and reduced the overall engine height, permitting lower bonnets. The crankshaft ran in five main bearings. The pistons are aluminium with three rings. All slant-fours are oversquare, with the larger capacity versions being even more so, as the increase in displacement came from increasing the bore diameter while holding the stroke length constant. The cylinder head was cast from aluminium alloy. Combustion chambers were wedge-shaped. The single overhead camshaft was driven by a single-row ⅜" chain. The eight valves, two per cylinder, were inline and were operated on by the camshaft through bucket tappets with shims for adjustment. Sprint 16-valve engine Triumph added a unique 16-valve cylinder head to the slant-four for the 1973 Dolomite Sprint. At the time there were at British Leyland (BL) both Harry Mundy, who worked on engine development at Jaguar, and Walter Hassan, also at Jaguar but in charge of engine technology development at BL as well. These two shared data on four-valve cylinder heads with King. A team of engineers led by King and "with co-operation from Harry Mundy and the engineers at Coventry Climax", developed a 4-valve-per-cylinder head where all of the valves are actuated by a single camshaft rather than the more conventional DOHC arrangement. The valves are arranged in two rows of eight, inclined 27° from vertical. The inlet valves are