|1965 to 1993|
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 drive DOHC system after 1980. All M family engines used a cast-iron block with an aluminum cylinder head. The Japanese market only M-E was the first Toyota engine to be equipped with fuel injection (at 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 30 years. They were commonly found on the large Toyota Crown, Cressida, Celica Supra, and Supra models.
The first M was a 2.0 L (1988 cc) version produced from 1965 through 1988. It was a 2-valve SOHC engine. Cylinder bore and stroke was square at 75 mm (2.95 in). Output was 110–115 PS (81–85 kW) at 5200 to 5600 rpm, depending on specifications and model year. Typical torque is 116 lb·ft (157 Nm) at 3800 rpm.
An LPG version, the M-LPG, was produced from 1966 through 1988. The "M-C" engine, for commercial vehicles such as the Crown Van produces 105 PS (77 kW).
Twin SU sidedraft carburetors pushed output for the M-B and M-D to 125 PS (92 kW) at 5800 rpm.
Anti emissions versions, the M-U, M-U LPG and M-EU, replaced the M, M-LPG 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.
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 of 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.
The turbocharged M-TEU appeared in 1980 with 145 hp (108 kW) at 5600 rpm and 156 lb·ft (211 Nm) at 3000 rpm. It used a Garret T-03 turbo.
In 1983, Toyota added an air/water intercooler to the M-TEU. Output was bumped to 160 hp (119 kW) at 5600 rpm and 170 lb·ft (230 Nm) at 3000 rpm.
The 2-valve SOHC 2M was stroked an additional 85 mm (3.35 in) for 2.3 L (2253 cc). It was produced from September 1967 to September 1974. Output was 81–86 kW (109–115 bhp) at 5200 rpm and 159–172 N·m (117–127 lb·ft) at 3600 rpm.
1970 Toyota Crown 2M Engine x ray view.
Another 2.0 L (1988 cc) inline 6 engine, the 2-valve 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 2000GT, which 'Import Tuner' magazine has described as "the first true original Japanese supercar". Output was 150 bhp (112 kW) at 6600 rpm and 18.0 kg·m (177 N·m; 130 lb·ft) at 5000 rpm.
The engine was bored out to 80 mm (3.15 in) to create the 2.6 L (2563 cc) 2-valve SOHC 4M. Produced from 1972 through 1980, output was 108-122 hp (81-91 kW) at 5600 rpm and 134–141 lb·ft (181-191 Nm) at 3600 rpm.
The fuel-injected 4M-E was produced from 1978 through 1980. It was also a 2-valve SOHC engine. Output was 110 hp (82 kW) at 4800 rpm and 136 lb·ft (184 Nm) at 2400 rpm.
The bore was up again to 83.1 mm (3.27 inches) in the 2.8 L (2759 cc) 5M, produced from 1979 through 1988. Although 2-valve SOHC and carbureted versions were made, it is the fuel-injected DOHC 5M-GE that is the most common.
The SOHC engine produced just 116 hp (87 kW) at 4800 rpm and 145 lb·ft (196 Nm) at 3600 rpm.
In Australia the 5M-E (in 1985) was just 103 kW at 4800 rpm and 226 Nm at 3600 rpm due to the leaded petrol at the time.
In Europe the 5M-E produced 145PS/ 107 kW in the Crown MS112 and the Celica Supra MA61.
The 12-valve (2 valves per cylinder) DOHC 5M-GE is familiar as the engine of the Toyota Supra and Toyota Cressida of the 1980s. It was quite different from any previous member of the M family, with Bosch L Jetronic-derived electronic fuel injection (using an AFM intake measuring scheme), wide-angle valves, and belt-driven dual camshafts. It used hydraulic valve lifters, a first for Toyota. The use of rocker arms and valve lash adjusters eliminated the need for valve clearance maintenance, a world first for any twin cam engine.This version of the M made its US debut in 1982's Toyota Celica Supra MK2. The 1982 version had a vacuum-advance distributor, whereas the 1983–1988 versions found in the Celica Supra and Cressida had full electronic control of the ignition system and distributor. The newer engine control system found in these later cars was named TCCS, or Toyota Computer Control System and, together with different intake runners, increased max power by 5 PS from August 1983.
Output ranged from 145 to 175 hp (108 and 130 kW respectively), depending on exhaust system, emissions controls, compression ratio, intake runner shape (earlier models had round intake runners and later models had D-shaped intake runners), and ECU tuning.
There were aftermarket crank and piston kits offered for the 5M-GE that took the displacement up to 2.9 L (for 230 hp/171 kW) and 3.1 L (for 250 hp/186 kW). Outfitted with kits like the Kuwahara 3100, these engines were often used quite successfully in powerboat racing in the mid 1980s.
Differences between years on US model of the Celica Supra:
Toyota increased the 5M-GE's stroke to 91 mm (3.58 in) to create the 3.0 L (2954 cc) 6M-GE. This necessitated the fitment of larger diameter intake runners (37 versus 35 mm). Only produced in 12-valve (2 valves per cylinder) DOHC/fuel-injected versions, it was available as the 6M-GE and Japan-spec 6M-GEU from 1984 through 1987. The 6M engine used the same crank, machined to accept a different torsional damper, as the 1986–1989 7M-GE and 7M-GTE engines; this fact is witnessed by the designation "6M" stamped on the counterweight of the crank on the earlier 1986–1988 7M engines.
Output was 170-190 hp (127-142 kW) at 5600 rpm and 170–192 lb·ft (230-260 Nm) at 4400 rpm. The 6M-GEU is usually the lower powered variant of 6M engines, due to more restrictive exhaust and increased emissions-control hardware. Even though it was never offered in US-market vehicles, it is sometimes imported from countries where it was available and transplanted into US-market Celica Supras and MX63 and MX73 Cressidas, since it is externally identical to the 5M-GE.
The Toyota 7M-GE introduced in the early months of 1986 is a 3.0-litre (2954 cc) 24-valve (4 valves per cylinder) DOHC/fuel-injected engine. The valves are spaced at a performance-oriented 50° angle. Cylinder bore is 83 mm (3.27 in) and stroke is 91 mm (3.58 in).
The 7M-GE was produced from 1986 through 1992. Output was 190-204 hp (142-152 kW) at 6000 rpm and 185–196 lb·ft (250-265 Nm) at 4800 rpm.
The turbocharged 7M-GTE was produced from 1986 to 1992. Output was 173 kW (232 hp) at 5600 rpm and 325 N·m (240 ft·lb) at 4000 rpm for most 5 psi (0.34 bar) versions. It was Toyota's top performance engine until it was replaced by the 1JZ-GTE.
A special 7M-GTEU version, with a modified CT26 high-flow turbocharger and large volume intercooler, pushed output to 267 hp (199 kW) at 5600 rpm and 358 N·m (264 ft·lb) at 4400 rpm. This was used only in the racing homologation Toyota Supra Turbo A road and race cars. The Turbo A models also measured air based on manifold pressure rather than using an air flow meter, had a larger intercooler, larger throttle body, optimized CT-26 turbo, and various other differences. It was the fastest Japanese car at the time. The homologation was for the Group A series. The Group A Supra with a 7M-GTE and CT26 turbo produced 433 kW (580 bhp).