Toyota Motor Corporation's M family of engines were a longitudinally mounted straight-6 engine design. They were used from the 1960s through the 1990s. All M family engines were OHC designs. While the M family was born with a chain-driven single camshaft it evolved into a belt-driven DOHC system after 1980. All M family engines used a cast-iron block with an aluminum cylinder head, and were built at the Toyota Kamigo plant in Toyota City, Japan.
The M-E variant, available only in the Japanese domestic market, was the first Toyota engine to be equipped with fuel injection (around the same time as the 4-cylinder 18R-E). The 4M-E was the first Toyota engine to be equipped with fuel injection for non-Japanese markets. The M family were Toyota's most prestigious engines (apart from the uncommon V family V8) for over 30 years. They were commonly found on the large Toyota Crown, Mark II, and Supra models.
M
The first M was a version produced from 1965 through 1988. It was a 2-valve SOHC engine. Cylinder bore and stroke was square at . Output was at 5,200 to 5600 rpm, depending on specifications and model year. Typical torque is at 3,800 rpm.
The "M-C" engine, for commercial vehicles such as the Crown Van produces .
Twin sidedraft SU Carburettors pushed output for the M-B and M-D to at 5,800 rpm.
Anti emissions versions, the M-U and M-EU, replaced the M and M-E on the Japanese market in mid 1976. The emissions system was called TTC (Toyota Total Clean), with a "-C" to denote the installation of a catalytic converter. For commercial vehicles, the emissions controlled carburetted version was called the M-J.
Applications (calendar years): 1962–1967 Toyota Crown MS40 (second generation) 1967–1971 Toyota Crown MS50 (third generation) 1971–1974 Toyota Crown MS60/62/70 (fourth generation) 1974–1979 Toyota Crown MS80/82/87/90/100/102/107 (fifth generation) 1979–1983 Toyota Crown MS117V (seventh generation) 1972–1979 Toyota Corona Mark II X10/20/30/40
M-P
An LPG version, the M-P and M-PU was produced from 1966 through 1989. The earliest models were simply called the M-LPG, with the emissions scrubbed M-PU replacing it in mid-1976.
1983–1987 Toyota Crown MS120 (seventh generation) 1987–1989 Toyota Crown MS130 (eighth generation)
M-E
The M-E appeared in the 1972–1976 Toyota Corona Mark II LG sedan and hardtop as sold in Japan. It was not sold outside Japan.
The M-E was redesignated as the M-EU for the Japanese market in December 1976 when it received the TTC-C (Toyota Total Clean), catalytic converter to meet anti-emissions laws.
Applications (calendar years): 1972–1980 Toyota Corona Mark II L and LG sedan and hardtop
M-TEU
The turbocharged M-TEU appeared in 1980 with at 5,600 rpm and at 3,000 rpm. It used a Garret T-03 turbo.
In 1983, Toyota added an air/water intercooler to the M-TEU. Output was bumped to at 5,600 rpm and at 3,000 rpm.
Applications (calendar years): 1980 Toyota Supra MA46 1980 Toyota Soarer MZ10 1980 Toyota Crown 1980 Toyota Corona Mark II 1982–1986 Toyota Celica XX (Japan)
2M
The 2-valve SOHC 2M was stroked to for . It was produced from November 1966 to September 1974. Output was at 5,200 rpm and at 3,600 rpm.
Applications (calendar years): Crown MS45/47 (November 1966 – August 1967) Crown MS51/53/55/57 (September 1967 – January 1971) Crown MS64/67 (February 1971 – September 1974) Corona Mark II MX12/22/28 (1972–74) 2000GT MF12
3M
Another naturally aspirated inline 6, with both squared bore and stroke of and equipped with 3 Mikuni-Solex 40 PHH carburetors, the 2 valves per cylinder DOHC 3M, was produced from 1966 through 1971. This special engine shared the original M's block but featured an aluminum sump, a special Yamaha-designed aluminum head with wide 79° valves and a hemispherical shape. It powered the Yamaha/Toyota MF10 2000GT, which 'Import Tuner' magazine has described as "the first true original Japanese supercar". Output was at 6,600 rpm and at 5,000 rpm and a Compression ratio of 8.4:1.
Applications (calendar years): Toyota 2000GT MF10
4M
The engine was bored out to to create the 2-valve SOHC 4M. Produced from 1972 through 1980, output was at 5,600 rpm and at 3,600 rpm.
The fuel-injected 4M-E was produced from 1978 through 1980. It was also a 2-valve SOHC engine. Output was at 4,800 rpm and at 2,400 rpm.
Applications (calendar years): 1978–1980 Toyota Supra 1974–1980 Corona Mark II/Cressida/Chaser 1971–1979 Toyota Crown
