| Mitsubishi 6G7 engine | |
|---|---|
 6G75 in a 2005Mitsubishi 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 & 4 valves × cyl. DOHC4 valves × cyl. withMIVEC (on some versions) |
| Compression ratio | 8.0–10.5:1 |
| Combustion | |
| Supercharger | OnDebonair only. |
| Turbocharger | withintercooler (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 |
The6G7 series orCyclone V6 engine is a series ofV6piston engines fromMitsubishi Motors. Five displacement variants were produced from 1986 to 2021, with bothSOHC andDOHC, naturally aspirated and turbo charged layouts. The 2.5, 3.0, and 3.5 L versions were also available withgasoline direct injection.MIVECvariable valve timing was used in some versions 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 theMitsubishi GTO, and became the most powerful car ever built by the company at the time.
This engine was also manufactured byHyundai Motor Company in South Korea as theHyundai Sigma engine.
| Engine code | Displacement | Bore × stroke |
|---|---|---|
| 6G71 | 2.0 L; 121.9 cu in (1,998 cc) | 74.7 mm × 76 mm (2.94 in × 2.99 in) |
| 6G72 | 3.0 L; 181.4 cu in (2,972 cc) | 91.1 mm × 76 mm (3.59 in × 2.99 in) |
| 6G73 | 2.5 L; 152.4 cu in (2,497 cc) | 83.5 mm × 76 mm (3.29 in × 2.99 in) |
| 6G74 | 3.5 L; 213.4 cu in (3,497 cc) | 93 mm × 85.8 mm (3.66 in × 3.38 in) |
| 6G75 | 3.8 L; 233.6 cu in (3,828 cc) | 95 mm × 90 mm (3.74 in × 3.54 in) |
The 2.0-litre6G71 model featuredSOHC 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]
Asupercharger was installed and exclusive to theDebonair. 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 onLPG, a version which was only available to the Debonair and mainly intended for commercial (taxi) use.
The 3.0-litre6G72 was manufactured in three different models which featuredSOHC with 12 valves,SOHC with24 valves, andDOHC 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 manyChrysler 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 innaturally 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.
The 2.5-litre6G73 is a 24-valve SOHC design with two valves running off a single cam lobe on the exhaust valves using a forkedrocker 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, whilepent-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 thecombustion 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]
The 3.5-litre6G74 is a 24-valve unit available with either SOHC, DOHC, orMIVEC 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-madeMagna 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 theMagna Ralliart. For the MIVEC, only available in theMitsubishi 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 usesMulti-port fuel injection and usesforged steelconnecting rods.
Thegasoline 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 uniquefuel 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 10.0:1compression ratio. Mitsubishi claimed 30 percent better fuel economy, a 30 percent reduction in emissions, and higher power outputs than diesels.[4]
The 3.8-liter6G75'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. The block was taller than that of the 3.5-liter 6G74. The pistons were high-pressure castings, joined to forged steel connecting rods and a heat-treated, forged steel crankshaft.[5] 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.
