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 2.0-litre 6G71 model featured SOHC and produced 88 kW at 5,500 rpm and 172 Nm 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 at 5,000 rpm and 16.1 kgm at 4,000 rpm. A supercharger was installed and exclusive to the Debonair. It produces 150 PS at 5,000 rpm and 221 Nm 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.

Applications

6G72

The 3.0-litre 6G72 was manufactured in three different models which featured SOHC with 12 valves, SOHC 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 at 5500 rpm with 278 Nm 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 at 5000 rpm and 172 lbft of torque at 3600 rpm. The Mitsubishi models were with a 3.0L 6G72 engine SOHC 24-valve developing 195 hp at 5000 rpm and 205 lbft of torque at 4000 rpm. For the MIVEC engine, output was 273 PS at 6000 rpm and 304 Nm at 4500 rpm. The SOHC 12-valve for the second generation of Pajero could produce up to 109 kW and 235 Nm, whereas the SOHC 24-valve could produce up to 133 kW and 255 Nm. The DOHC 24-valve was used in the Mitsubishi Debonair, 3000GT, and Dodge Stealth producing 222 hp and 205 lbft of torque with a 10.0:1 compression ratio in naturally aspirated form, and as much as 320 hp and 315 lbft of torque in turbocharged form. 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.

Applications

6G73

The 2.5-litre 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 x; it is a 60-degree V6 and weighs around 155 kg. 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 in diameter while exhaust valves are 29 mm. 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 at 5,900 rpm with 221 Nm of torque at 4,350 rpm.

Applications

6G74

The 3.5-litre 6G74 is a 24-valve unit available with either SOHC, DOHC, or MIVEC DOHC. Output for the SOHC version varies from 139 kW at 4,750 rpm with 306 Nm of torque at 3,750 rpm in the Pajero to the highest output of 164 kW at 5,250 rpm with 318 Nm of torque at 4,500 rpm in the Australian-made Magna Sports, VR-X and Verada GTV/GTVi and 180 kW at 5,500 rpm with 333 Nm 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 at 6,000 and 324 Nm 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.

Applications

6G75

The 3.8-liter 6G75 's output varied from 160 kW and 339 Nm to 205 kW and 393 Nm 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. 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.

Specifications

Applications