Mitsubishi 6G7 engine
6G75 in a 2005 Mitsubishi Galant GTS
Overview
Manufacturer	Mitsubishi Motors
Production	1986–2021
Layout
Configuration	60° V6
Displacement	2.0–3.8 L; 121.9–233.6 cu in (1,998–3,828 cc)
Cylinder bore	74.7 mm (2.94 in) 83.5 mm (3.29 in) 91.1 mm (3.59 in) 93 mm (3.66 in) 95 mm (3.74 in)
Piston stroke	76 mm (2.99 in) 85.8 mm (3.38 in) 90 mm (3.54 in)
Valvetrain	SOHC 2 valves × cyl. DOHC 4 valves × cyl. with MIVEC (on some versions)
Compression ratio	8.0–10.5:1
Combustion
Supercharger	On Debonair only.
Turbocharger	with intercooler (on some versions)
Fuel system	Multi-port fuel injection Direct injection
Fuel type	Gasoline
Oil system	Pressure feed, full-flow filtration with Trochoid type oil pump
Cooling system	Water-cooled
Output
Power output	105–324 PS (77–238 kW; 104–320 hp)
Torque output	116–315 lb⋅ft (157–427 N⋅m)
Dimensions
Dry weight	around 155 kg (342 lb)
Chronology
Successor	Mitsubishi 6B3 engine

The 6G7 series or Cyclone V6 engine is a series of V6 piston engines from Mitsubishi Motors. Five displacement variants were produced from 1986 to 2021, with both SOHC and DOHC, naturally aspirated and turbo charged layouts. While MIVEC variable valve timing has also been implemented in some versions the 2.5, 3.0, and 3.5 L versions were also available with gasoline direct injection. This engine has been the flagship powerplant of the company except when they briefly built a V8 in 1999–2001. The staple of their high-end sedans, it was given twin-turbos for the Mitsubishi GTO, and became the most powerful car ever built by the company at the time.

Bore and Stroke

6G71

The 6G71 model featured SOHC and produced 88 kW (120 PS; 118 hp) at 5,500 rpm and 172 N⋅m (127 lbf⋅ft) at 4,500 rpm. It was installed with two valves per cylinder, and used Mitsubishi's ECI-Multi multiple port fuel injection fuel delivery system. The compression ratio was 8.9:1. An earlier version, with single-point fuel injection, only had 105 PS (77 kW; 104 hp) at 5,000 rpm and 16.1 kg⋅m (158 N⋅m; 116 lb⋅ft) at 4,000 rpm.^[1]

A supercharger was installed and exclusive to the Debonair. It produces 150 PS (110 kW; 148 hp) at 5,000 rpm and 221 N⋅m (163 lbf⋅ft) at 3,000 rpm. The compression ratio for the supercharged model is 8.0:1. The 6G71 engine was also converted to run on LPG, a version which was only available to the Debonair and mainly intended for commercial (taxi) use.

6G72

The 6G72 was manufactured in three different models which featured SOHC with 12 valves, DOHC with 24 valves, and DOHC with 24 valves.

The latest version was used in the Mitsubishi Eclipse GT and Galant. Output in 2004 was 210 hp (157 kW; 213 PS) at 5500 rpm with 278 N⋅m (205 lbf⋅ft) of torque at 4000 rpm. In the older version, used in many Chrysler models since 1987, this V6 was an SOHC 12-valve developing 141 hp (105 kW; 143 PS) at 5000 rpm and 172 lb⋅ft (233 N⋅m) of torque at 3600 rpm. The Mitsubishi models were with a 3.0L 6G72 engine SOHC 24-valve developing 195 hp (145 kW; 198 PS) at 5000 rpm and 205 lb⋅ft (278 N⋅m) of torque at 4000 rpm. For the MIVEC engine, output was 273 PS (201 kW; 269 hp) at 6000 rpm and 304 N⋅m (224 lb⋅ft) at 4500 rpm.

The SOHC 12-valve for the second generation of Pajero could produce up to 109 kW (148 PS; 146 hp) and 235 N⋅m (173 lb⋅ft), whereas the SOHC 24-valve could produce up to 133 kW (181 PS; 178 hp) and 255 N⋅m (188 lb⋅ft).

The DOHC 24-valve was used in the Mitsubishi Debonair, 3000GT, and Dodge Stealth producing 222 hp (166 kW; 225 PS) and 205 lb⋅ft (278 N⋅m) of torque with a 10.0:1 compression ratio in naturally aspirated form, and as much as 320 hp (239 kW; 324 PS) and 315 lb⋅ft (427 N⋅m) of torque in turbocharged form.^[2] The turbocharged variant had the lowest compression ratio at 8.0:1, with each bank of the V6 having its own independent turbocharger and intercooler. Turbochargers were built by Mitsubishi.

6G73

The 6G73 is a 24-valve SOHC design with two valves running off a single cam lobe on the exhaust valves using a forked rocker arm and each intake valve actuated with two cam lobes, with a smaller bore than the 3.0L version of the same block. Bore and stroke are 83.5 mm × 76 mm (3.29 in × 2.99 in); it is a 60-degree V6 and weighs around 155 kg (342 lb). The engine has low-profile cast aluminum heads which help it to fit into compact engine bays, while pent-roof combustion chambers increase efficiency and make room for four valves per cylinder, arranged in a cross-flow pattern with a "tumble" intake port for both strong breathing and low emissions. Spark plugs are centered in the combustion chambers. The intake valves are 33 mm (1.30 in) in diameter while exhaust valves are 29 mm (1.14 in). The SOHC 24 valve version of the 6G72 uses these same cylinder heads. A toothed timing belt is used. The output of 6G73 is 163 PS (120 kW; 161 hp) at 5,900 rpm with 221 N⋅m (163 lb⋅ft) of torque at 4,350 rpm.^[3]

6G74

The 6G74 is a 24-valve unit available with either SOHC, DOHC, or MIVEC DOHC. Output for the SOHC version varies from 139 kW (189 PS; 186 hp) at 4,750 rpm with 306 N⋅m (226 lb⋅ft) of torque at 3,750 rpm in the Pajero to the highest output of 164 kW (223 PS; 220 hp) at 5,250 rpm with 318 N⋅m (235 lb⋅ft) of torque at 4,500 rpm in the Australian-made Magna Sports, VR-X and Verada GTV/GTVi and 180 kW (245 PS; 241 hp) at 5,500 rpm with 333 N⋅m (246 lb⋅ft) of torque at 4,000 rpm in the Magna Ralliart. For the MIVEC, only available in the Mitsubishi Pajero Evolution, the output is 209 kW (284 PS; 280 hp) at 6,000 and 324 N⋅m (239 lb⋅ft) at 4,500 rpm. It uses Multi-port fuel injection and uses forged steel connecting rods.

The gasoline direct injection version of the 6G74 was launched in April 1997 as the first GDI V6 engine ever produced. It differed from the basic 6G74 in many ways apart from its unique fuel injection system—it had a crown-curved rather than flat piston head, upright intake ports rather than angled, and a 10.4:1 rather than a 10.0:1 compression ratio. Mitsubishi claimed 30 percent better fuel economy, a 30 percent reduction in emissions, and higher power outputs than diesels.^[4]

6G75

The 6G75's output varied from 160 kW (218 PS; 215 hp) and 339 N⋅m (250 lb⋅ft) to 205 kW (279 PS; 275 hp) and 393 N⋅m (290 lb⋅ft) depending on application. In the interest of durability, the pistons were high-pressure castings attached to forged steel connecting rods that swing from a heat-treated forged steel crankshaft. Intended to be used with 95 RON fuel, lower octane fuels would be detected by the vehicle's knock sensors, and the engine detuned to compensate.

See also

Wikimedia Commons has media related to Mitsubishi 6G7 engines.

• List of Mitsubishi engines
• List of engines used in Chrysler products
• Hyundai Sigma engine

References

5. https://media.mitsubishicars.com/channels/2004-Galant/releases/d8fa6a4a-5172-57cd-7b04-a59f4b06fbf0