Mitsubishi 6G74 Specifications
| Engine Model: Mitsubishi 6G74 |
| Engine Type: 4-cycle 6-cylinder V-block liquid-cooled gasoline |
| Total Displacement: 213.4 cu.in (3.49 L) |
| Rated Engine Power: 186-280 Hp (139-209 kW) at 4500-6500 rpm |
| Fuel System Type: Multi-point electronic fuel injection |
____________________________________________________________________________________
The Mitsubishi 6G74 is a 3.5-liter V6 engine belonging
to the 6G7 (Cyclone) family, representing one of the most powerful naturally
aspirated variants within the series. Produced throughout the 1990s and early
2000s, the 6G74 served as the flagship powertrain for Mitsubishi’s sport utility
vehicles, including the Pajero (Montero), Challenger, and the high-performance
Pajero Evolution. The engine features a 60-degree V6 configuration with a cast
iron cylinder block and aluminum alloy cylinder heads.
Three valvetrain configurations were offered over its production life: single
overhead camshaft (SOHC) with 24 valves, dual overhead camshaft (DOHC) with 24
valves, and DOHC with MIVEC (Mitsubishi Innovative Valve timing and lift
Electronic Control) variable valve timing and lift. The 6G74 is recognized for
its high torque output, durability, and the advanced MIVEC system that elevated
power output to 280 hp in naturally aspirated form.
Engine Type: 60° V6, 4-cycle, water-cooled, gasoline.
Displacement: 3,497 cc (213.4 cu.in).
Bore: 93.0 mm (3.66 in).
Stroke: 85.8 mm (3.38 in).
Firing Order: 1-2-3-4-5-6 (cylinder bank: left 1, 3, 5; right 2, 4, 6).
Compression Ratio:
SOHC variants: 9.5:1-10.0:1.
DOHC variants: 10.0:1-10.5:1.
MIVEC variants: 10.5:1.
Valvetrain Configurations:
SOHC 24v: Single Overhead Camshaft per cylinder bank operating 24 valves (4
valves per cylinder).
Camshafts are driven by a toothed timing belt. Hydraulic lash adjusters are
incorporated.
DOHC 24v: Dual Overhead Camshaft per cylinder bank operating 24 valves (4 valves
per cylinder).
Camshafts are driven by a toothed timing belt. Hydraulic lash adjusters are
incorporated.
DOHC MIVEC: Dual Overhead Camshaft per cylinder bank with variable valve timing
and lift control on the intake valves. The system utilizes two distinct cam
profiles per cylinder, with hydraulic switching mechanisms that engage
higher-lift, longer-duration profiles above predetermined engine speed
thresholds.
Maximum Power:
SOHC variants: 186-200 hp (139-149 kW) @ 4,500-5,000 rpm.
DOHC variants: 208-230 hp (155-172 kW) @ 5,500-6,000 rpm.
MIVEC variants: 280 hp (209 kW) @ 6,500 rpm.
Maximum Torque:
SOHC variants: 300-314 Nm (221-232 lb-ft) @ 3,000-3,500 rpm.
DOHC variants: 311-324 Nm (229-239 lb-ft) @ 4,500-5,000 rpm.
MIVEC variants: 348 Nm (257 lb-ft) @ 4,000 rpm.
The cylinder block is manufactured from cast iron with
a 60-degree V-angle configuration. Bore diameter measures 93.0 mm (3.66 in). The
block features a deep-skirt design with reinforced bulkheads to withstand the
loads generated by the engine’s compression ratios and power outputs. Pressed-in
cast iron cylinder liners are utilized.
The crankshaft is forged steel with eight
counterweights, supported by four main bearings. The block incorporates
an integrated oil gallery system feeding the main bearings, connecting
rods, and hydraulic lash adjusters. The cylinder block is shared across
6G7 family engines with bore and stroke variations differentiating
displacement.
Each cylinder head is manufactured from aluminum alloy
with pent-roof combustion chambers and cross-flow port architecture.
Valves: 24 total; 12 intake, 12 exhaust.
Intake Valve Diameter: 34.0 mm (1.34 in) for SOHC and DOHC variants.
Intake Valve Diameter: 35.0 mm (1.38 in) for MIVEC variants.
Exhaust Valve Diameter: 30.0 mm (1.18 in) across all variants.
Valve Stem Diameter: 6.0 mm (0.24 in) for both intake and exhaust.
Valve Seat Inserts: Powder metal sintered alloy with multi-angle seat geometry.
Valve Guides: Press-fit sintered iron guides.
Hydraulic Lash Adjusters: Used across all valvetrain configurations, these units
automatically maintain zero valve clearance throughout engine life using engine
oil pressure. Valve Springs: Progressive-rate springs designed to accommodate
the increased lift of MIVEC operation without valve float.
Camshafts: Chilled cast iron camshafts with induction-hardened lobes. SOHC
variants utilize a single camshaft per bank operating all valves through rocker
arms. DOHC and MIVEC variants utilize separate intake and exhaust camshafts per
bank with bucket-type followers.
MIVEC System: On MIVEC variants, the intake camshaft incorporates two distinct
lobe profiles per valve. A hydraulic switching mechanism, activated by oil
pressure controlled by the engine control unit, locks the rocker arms to the
high-lift profile above 4,500-5,000 rpm. Intake valve lift increases from 8.5 mm
(0.33 in) to 10.0 mm (0.39 in), and duration increases from 220 degrees to 250
degrees at 1.0 mm lift.
The fuel system employs multi-point electronic fuel
injection with sequential injection timing across all variants. Injection Type:
Sequential multi-port injection with fuel injectors positioned in the intake
manifold runners adjacent to each intake port. Engine Management System:
Mitsubishi-engineered ECU with inputs from a mass airflow sensor (hot-wire
type), throttle position sensor, coolant temperature sensor, intake air
temperature sensor, crankshaft position sensor, camshaft position sensors, and
oxygen sensors.
Fuel Pressure: Regulated to 2.8-3.2 bar (41-46 psi) via a vacuum-referenced fuel
pressure regulator mounted on the fuel rail. Injector Flow Rate: 240-280 cc/min
depending on variant and power output. Fuel Pump: In-tank electric fuel pump
with flow rate calibrated for the engine’s maximum output.
Intake Manifold: Aluminum manifold with individual runners per cylinder. SOHC
and DOHC variants utilize fixed runner lengths. Some variants incorporate a
variable intake manifold with internal butterfly valves (swirl control valves)
that alter intake port velocity at low engine speeds to improve combustion
efficiency.
The lubrication system is a full-flow, pressurized
design utilizing a rotor-type oil pump driven by the crankshaft. Oil Pump Type:
Internal gear (gerotor) pump mounted to the front of the crankshaft, housed
within the front timing cover assembly. Oil Capacity: 4.6-4.9 liters (4.9-5.2
qt) including oil filter replacement. Capacity varies with oil cooler
configuration. Recommended Oil Viscosity: 5W-30 or 10W-30. Synthetic oil is
recommended for MIVEC variants due to the hydraulic switching mechanism
requirements.
Oil Quality Requirement: API SG, SH, SJ, SL, or later classifications. Oil
Pressure: At warm idle, pressure ranges from 1.0-1.8 bar (14-26 psi). At 3,000
rpm, pressure reaches 3.5-4.5 bar (51-65 psi). Oil Cooler: Liquid-to-oil
plate-type heat exchanger is incorporated on DOHC and MIVEC variants, mounted
between the oil filter and cylinder block. Oil Filter: Full-flow spin-on
canister type mounted to the cylinder block.
The cooling system is pressurized and utilizes a
centrifugal water pump driven by the timing belt. Water Pump Type: Centrifugal
pump with a die-cast aluminum housing and stamped steel impeller. Thermostat:
Wax-pellet type located in the coolant outlet housing. Opening temperature is
82-88 °C (180-190 °F).
Coolant Capacity: 7.5-8.5 liters (7.9-9.0 qt) inclusive of engine block, heater
core, and radiator. System Pressure: Radiator cap rated at 1.1 bar (16 psi).
Coolant Specification: Ethylene glycol-based coolant with corrosion inhibitors
suitable for mixed-metal (cast iron and aluminum) engine construction.
Radiator: Cross-flow aluminum core with plastic end tanks. Cooling fan
configuration consists of an engine-driven mechanical fan with a viscous clutch
on longitudinal applications; electric fans are used on transverse applications.
| Intake and Exhaust Systems |
Exhaust System: Cast iron exhaust manifolds with
individual collectors per bank, merging into a single exhaust pipe downstream. A
dual catalytic converter system (one per bank) is utilized on vehicles with
closed-loop fuel management.
Intake System: Air induction utilizes a large-volume air cleaner housing with a
resonator to reduce induction noise. The throttle body incorporates an
electronically controlled idle air control valve.
Distributor-based ignition on early SOHC variants;
distributorless ignition system (DIS) with individual ignition coils
(coil-on-plug) on DOHC and MIVEC variants. The DIS system utilizes a crankshaft
position sensor and dual camshaft position sensors for sequential ignition
timing. Spark Plug Type: NGK BKR5E-11 (SOHC/MPI); NGK BKR6E-11 (DOHC); NGK
IFR6E11 or equivalent (MIVEC). Spark Plug Gap: 1.0-1.1 mm (0.039-0.043 in) for
MPI variants; 0.7-0.8 mm (0.028-0.031 in) for MIVEC variants.
Timing System: Toothed timing belt constructed from
high-tensile rubber with fiber reinforcement. The belt drives the camshafts and
water pump. An automatic spring-loaded tensioner maintains belt tension. The
engine is interference; timing belt failure results in piston-to-valve contact.
Replacement interval is 100,000 km (60,000 miles) or 5 years.
Crankcase Ventilation: Positive Crankcase Ventilation (PCV) system with a PCV
valve mounted on one cylinder bank and a balance tube connecting both banks.
Overall Length: 620 mm (24.4 in) measured from
accessory drive pulley face to transmission mounting flange.
Overall Width: 680 mm (26.8 in) inclusive of intake manifold, throttle body, and
exhaust manifold heat shields.
Overall Height: 700 mm (27.6 in) from oil pan bottom surface to valve cover top
surface.
Dry Weight: 155-170 kg (342-375 lb) depending on valvetrain configuration (MIVEC
adds 5 kg / 11 lb) and accessory drive components.
Valve Clearance: Hydraulic lash adjusters operate
automatically. No periodic adjustment required. Timing Belt Replacement
Interval: 100,000 km (60,000 miles) or 5 years, whichever occurs first.
Replacement includes belt, tensioner, and idler pulleys. Spark Plug Replacement
Interval: 100,000 km (60,000 miles) for platinum or iridium plugs; 30,000 km
(18,600 miles) for standard copper-core plugs.
Drive Belt Tension (Accessory): 8-10 mm (0.31-0.39 in) deflection under 10 kg
(22 lb) of force at the midpoint of the longest span. Automatic tensioners are
used on later variants. Coolant Change Interval: 48,000 km (30,000 miles) or 2
years. Engine Oil Change Interval: 5,000-7,500 km (3,100-4,700 miles) depending
on operating conditions and oil quality.
Idle Speed (warm, neutral): 700-750 rpm for SOHC variants; 650-700 rpm for DOHC
and MIVEC variants. Ignition Timing: 5°-8° BTDC for distributor-equipped
variants; electronically controlled with no manual adjustment for DIS variants.
Fuel Pressure: 2.8-3.2 bar (41-46 psi) with vacuum line disconnected from fuel
pressure regulator.
Cylinder Head Bolts (cold), Step 1: 30 Nm (22 lb-ft).
Cylinder Head Bolts (cold), Step 2: 60 Nm (44 lb-ft) plus 90° rotation.
Crankshaft Damper Pulley Bolt: 200-220 Nm (148-162 lb-ft).
Connecting Rod Cap Bolts: 40-45 Nm (30-33 lb-ft) plus 90° rotation.
Main Bearing Cap Bolts: 60-65 Nm (44-48 lb-ft) plus 90° rotation.
Camshaft Bearing Cap Bolts: 20-25 Nm (15-18 lb-ft).
Camshaft Sprocket Bolts: 80-90 Nm (59-66 lb-ft).
Valve Cover Bolts: 8-10 Nm (6-7 lb-ft).
Intake Manifold Nuts/Bolts: 20-25 Nm (15-18 lb-ft).
Exhaust Manifold Nuts: 30-35 Nm (22-26 lb-ft).
Oil Pan Bolts: 10-12 Nm (7-9 lb-ft).
Oil Pump Mounting Bolts: 12-15 Nm (9-11 lb-ft).
Timing Belt Tensioner Bolt: 25-30 Nm (18-22 lb-ft).
Water Pump Bolts: 20-25 Nm (15-18 lb-ft).
Flywheel / Drive Plate Bolts: 90-100 Nm (66-74 lb-ft).
Engine Mount Bracket Bolts: 45-55 Nm (33-41 lb-ft).
Spark Plugs: 25-30 Nm (18-22 lb-ft).
Mitsubishi Pajero / Montero (V20, V40 series):
1994-2005. The 6G74 powered the mid-generation and later V20 series Pajero, as
well as the V40 series. SOHC variants were utilized in standard models; DOHC
variants appeared in higher-specification trims.
Mitsubishi Pajero Evolution (V55): 1997-1999. The MIVEC-equipped 6G74 was
developed exclusively for the Pajero Evolution homologation model, producing 280
hp (209 kW) and 348 Nm (257 lb-ft). This variant featured a reinforced cylinder
block, unique intake and exhaust systems, and a dedicated engine control unit
calibration.
Mitsubishi Challenger / Montero Sport (K90, K100 series): 1996-2005. The 6G74
was installed in the Challenger and Montero Sport SUVs, primarily in SOHC
configuration, providing the torque required for towing and off-road
applications.
Mitsubishi Delica (L400 series): 1994-2005. The 6G74 served as the gasoline V6
powertrain for the Delica Space Gear in markets where diesel engines were not
offered or where higher power output was specified.
Mitsubishi Diamante (F30, F40 series): 1995-2000. The 6G74 was utilized in the
Diamante sedan in transverse front-wheel-drive and all-wheel-drive
configurations, with DOHC variants appearing in higher-performance trims.
Mitsubishi Magna / Verada (TE, TF, TH series): 1995-2000. Australian-market
Magna and Verada sedans received the 6G74 in DOHC configuration, producing
208-230 hp (155-172 kW) depending on model year and emissions calibration.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
