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Mazda 12A rotary engine with 5 spd. transmission. In good condition. The 12A is an "elongated" version of the 10A — the rotor radius was the same, but the depth was increased by 10 mm (0.4 in) to 70 mm (2.8 in). Each of its two rotors displaced 573 cc for a total of 1146 cc. The 12A series was produced for 15 years, from May 1970 through 1985. In 1974, a 12A became the first engine built outside of western Europe or the U.S to finish the 24 hours of Le Mans. In 1974, a new process was used to harden the rotor housing. The Sheet-metal Insert Process (SIP) used a sheet of steel much like a conventional piston engine cylinder liner with a chrome plated surface. The side housing coating was also changed to eliminate the troublesome sprayed metal. The new "REST" process created such a strong housing, the old carbon seals could be abandoned in favor of conventional cast iron. Early 12A engines also feature a thermal reactor, similar to the 0866 10A, and some use an exhaust port insert to reduce exhaust noise. A lean-burn version was introduced in 1979 (in Japan) and 1980 (in America) which substituted a more-conventional catalytic converter for this "afterburner". A major modification of the 12A architecture was the 6PI which featured variable induction ports. Applications: 1970–1972 Mazda R100 1970–1974 Mazda RX-2, 130 hp (97 kW) and 156 Nm (115 lb·ft) 1972–1974 Mazda RX-3 (Japan), 110 hp (82 kW) and 135 Nm (100 lb·ft) 1972–1974 Mazda RX-4 1972–1980 Mazda Luce 1978–1979 Mazda RX-7, 100 hp (75 kW) Aero Design DG-1 racing aircraft used two Mazda RX-3 (12A) engines, each driving a propeller—one at the front, the other at the rear of the aircraft. Lean-burn 1979–1985 Mazda RX-7 (Japan) 1980–1985 Mazda RX-7 (USA) 6PI 1981–1985 Mazda Luce 1981–1985 Mazda Cosmo Turbo[edit] Turbocharged 12A installed in Mazda Cosmo The ultimate 12A engine was the electronically fuel-injected engine used in the Japan-spec HB series Cosmo, Luce,[2] and SA series RX-7.[3] In 1982 a 12A turbo powered Cosmo coupe was officially the fastest production car in Japan.[citation needed] It featured "semi-direct injection" into both rotors at once. A passive knock sensor was used to eliminate knocking, and later models featured a specially-designed smaller and lighter "Impact Turbo" which was tweaked for the unique exhaust signature of the Wankel engine for a 5 horsepower increase.[3] The engine continued until 1989 in the HB Cosmo series but by that stage it had grown a reputation as a thirsty engine. Original output is 160 PS (120 kW) at 6,500 rpm, and 226 N·m (167 lb·ft) at 4,000 rpm.[2] Impact Turbo output is 165 PS (121 kW) at 6,000 rpm, and 231 Nm (170 lb·ft) at 4,000 rpm. Applications: 1982–1989 Mazda Cosmo 1982–1985 Mazda Luce 1984–1985 Mazda RX-7
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