John Deere 6068HF485 Specifications
| Engine Model: John Deere PowerTech 6068HF485 |
| Engine Type: 4-stroke in-line 6-cylinder turbocharged liquid-cooled diesel |
| Total Displacement: 415 cu.in (6.8 L) |
| Rated Engine Power: 173-250 Hp (129-187 kW) at 2400 rpm |
| Fuel System Type: Common Rail Direct Injection |
____________________________________________________________________________________
The John Deere 6068HF485 is a 6.8-liter,
6-cylinder diesel engine from the PowerTech E product family. This
engine represents a Tier 3 / Stage IIIA emissions-compliant platform,
engineered for heavy-duty industrial, agricultural, and generator set
applications. The "HF" designation indicates a High-Function
configuration, while "485" refers to a specific power calibration within
the series.
Unlike earlier mechanical John Deere engines, the 6068HF485 employs a
High-Pressure Common-Rail (HPCR) fuel system with an electronic control
unit (ECU) managing injection timing, pressure, and duration.
Turbocharging with air-to-air aftercooling (ATAAC) delivers a 35% torque
rise, making this engine suitable for variable load operations such as
wood chipping, pumping, and heavy traction.
The design features a cast iron block, directed top-liner cooling, and a
500-hour oil change interval, reflecting a commercial duty cycle aimed
at reduced operating costs. Applications include large tractors, combine
harvesters, self-propelled forage harvesters, industrial compressors,
and standby generator sets in the 150-200 kW range.
The John Deere 6068HF485 is an inline, 4-cycle, turbocharged and
aftercooled diesel engine. It operates on the four-stroke principle with
a 6-cylinder configuration. The engine is designed for continuous
heavy-duty service at variable speeds, particularly in the 1500 to 2400
rpm range.
Engine Type: In-line, 4-cycle, turbocharged diesel with air-to-air
aftercooling.
Number of Cylinders: 6.
Displacement: 6.8 L (415 cu.in).
Bore x Stroke: 106 mm x 127 mm (4.17 in x 5.00 in).
Compression Ratio: 17.0:1.
Firing Order: 1-5-3-6-2-4.
Rated Power (Industrial): 187 to 250 hp (140 to 187 kW) at 2200 to 2400
rpm.
Standby Power (Gen Set, 60 Hz): 212 to 283 hp (158 to 211 kW) at 1800
rpm.
Prime Power (Gen Set, 50 Hz): 185 to 247 hp (138 to 184 kW) at 1500 rpm.
Peak Torque: 754 lb-ft (1023 Nm) at 1400 rpm.
Torque Rise: 35% from rated torque to peak torque.
Aspiration: Turbocharged and Air-to-Air Aftercooled (ATAAC). Compressed
intake air passes through an air-to-air heat exchanger mounted
separately from the engine coolant radiator.
Emission Standard: U.S. EPA Tier 3 (for non-road diesel engines) and EU
Stage IIIA. The engine achieves compliance through in-cylinder
combustion management without a Diesel Particulate Filter (DPF) or
Selective Catalytic Reduction (SCR).
0The cylinder block is manufactured from high-strength cast iron with a
deep-skirt design, extending below the crankshaft centerline. This
architecture increases crankshaft bearing support and reduces noise
emissions. The block incorporates six cylinder bores with replaceable
wet-type cylinder liners. Each liner is sealed at the bottom with two
O-rings and at the top by the cylinder head gasket.
A directed top-liner cooling system forces coolant to circulate at high
velocity around the upper 30 mm (1.18 in) of each liner, reducing piston
ring and liner temperatures. The block includes a structural oil pan
mounting face and integrated mounting feet for rubber isolating mounts.
The crankshaft is supported by seven main bearings (one at each cylinder
and one at each end of the block).
The cylinder head is a single-piece, cast-iron cross-flow design. Four
valves per cylinder (two intake, two exhaust) provide a total of 24
valves. The four-valve arrangement improves volumetric efficiency and
allows central placement of the fuel injector for optimum combustion
symmetry. The intake ports are high-swirl designs to promote air-fuel
mixing. The exhaust ports are merged within the cylinder head casting to
direct flow toward a single-entry turbocharger mounting flange.
Valve seats are powder-metal alloy, pressed and induction-hardened for
wear resistance. Valve guides are sintered iron. The valvetrain uses
roller rocker arms to reduce friction and hydraulic lash adjusters (HLA)
that maintain zero valve clearance, eliminating manual adjustment. The
overhead camshaft is not used; instead, a camshaft is located in the
cylinder block and drives pushrods and rocker arms.
The fuel system is a High-Pressure Common-Rail (HPCR) design operating
under full electronic control. A gear-type transfer pump draws fuel from
the tank through a serviceable primary filter with water separator. A
high-pressure pump, driven by the engine gear train, raises fuel
pressure to a maximum of 1600 bar (23,200 psi). Pressurized fuel
accumulates in a common rail mounted on the cylinder head.
Six electronically controlled injectors, one per cylinder, receive
control signals from the Engine Control Unit (ECU) to deliver precisely
metered fuel quantities. The ECU manages injection timing, rail
pressure, pilot injection events, and main injection duration based on
engine speed, load, coolant temperature, and intake air pressure. A
pilot injection event preceding the main injection reduces combustion
noise and peak cylinder pressure. The system includes a fuel return line
to the tank for cooling and de-aeration.
The lubrication system is a pressurized, full-flow filtration circuit. A
rotor-type oil pump, mounted on the front of the crankshaft, draws oil
through a strainer from a cast aluminum or fabricated steel sump. Oil
passes through a spin-on full-flow filter with a bypass valve that opens
at 35 psi (241 kPa) if the filter element becomes restricted. The system
then delivers oil to the crankshaft main bearings, connecting rod
bearings, camshaft bearings, rocker arms, and hydraulic lash adjusters.
A piston cooling jet system is integrated: six individual nozzles, one
per cylinder, direct a continuous stream of oil at the underside of each
piston crown to remove heat absorbed during combustion. A water-cooled
oil cooler, stacked within the engine coolant circuit, maintains oil
temperature within an optimal range.
Oil Capacity (with filter): 19.0 L (20.0 qt).
Recommended Oil Grade: John Deere Plus-50 II SAE 15W-40, or API CJ-4 or
CI-4.
Oil Pressure (at rated speed, warm engine): 45 to 60 psi (310 to 414
kPa).
Oil Pressure (at idle, warm engine): Minimum 15 psi (103 kPa).
The cooling system is a sealed, pressurized, centrifugal circulation
circuit. A belt-driven water pump moves coolant through a
thermostatically controlled loop. Coolant exits the top of the cylinder
head, passes through the radiator or heat exchanger, and returns to the
water pump inlet. A second circuit diverts coolant to the air-to-air
aftercooler in some integrated cooling packages, though the 6068HF485
primarily uses a separate air-to-air aftercooler independent of the
engine coolant.
The system incorporates a bypass passage that allows coolant to
circulate within the engine block and cylinder head until the thermostat
reaches opening temperature. A deaeration line bleeds air from the top
of the cylinder head to the coolant surge tank. The thermostat is a
wax-pellet, single-stage design.
Coolant Capacity (engine only, without radiator): 11.9 L (12.6 qt).
Thermostat Opening Temperature: 180°F (82°C).
Thermostat Fully Open Temperature: 203°F (95°C).
Maximum Coolant Pressure (radiator cap rating): 15 psi (103 kPa).
Recommended Coolant: JD Cool-Gard II or any low-silicate ethylene glycol
antifreeze.
| Intake and Exhaust Systems |
Air Intake System: The intake system draws air through a two-stage
dry-type paper filter (with a dust evacuation valve), then through the
turbocharger compressor, then through the air-to-air aftercooler, and
finally into the intake manifold. The manifold is a tuned-length runner
design with a throttle plate (used only for shutdown, not for load
control).
Exhaust System: The turbocharger is a fixed-geometry, wastegate-assisted
unit from Garrett or Holset. The exhaust manifold is a pulse-converged
design, grouping cylinders with 240-degree firing intervals to maintain
exhaust gas energy to the turbine. An optional muffler or exhaust spark
arrestor is available for specific applications.
Electrical System: Available in 12-volt or 24-volt configurations. The
12-volt system uses a gear-reduction starter motor rated at 4.0 kW and a
120-amp alternator. The 24-volt system uses a 5.5 kW starter and a
70-amp alternator. Both systems feature a negative ground.
Engine Control Unit (ECU): A Bosch EDU2X or John Deere-sourced ECU
mounted directly on the engine. The ECU controls the HPCR system,
monitors 20+ sensor inputs (crank position, cam position, rail pressure,
intake manifold temperature, coolant temperature, oil pressure, ambient
air pressure), and provides diagnostic fault codes via a J1939 CAN bus
interface. An electronic governor is integrated into the ECU software.
Cold Start Aid: A thermostart flame-type intake heater or an optional
electric grid heater in the intake manifold. Activation is automatic
below 32°F (0°C) and controlled by the ECU.
Dry Weight (without flywheel, starter, or alternator): 591 kg (1303 lb).
Overall Length (front pulley to flywheel face): 1050 mm (41.3 in).
Overall Width (exhaust manifold outer to oil fill tube outer): 700 mm
(27.6 in).
Overall Height (oil pan bottom to rocker cover top): 980 mm (38.6 in).
Crankshaft Centerline Height (from oil pan rail): 315 mm (12.4 in).
Oil Change Interval: 500 hours for industrial duty under normal load and
fuel sulfur content below 0.5%. Reduce to 250 hours for sustained
high-load operation or dusty environments. Oil Filter Replacement: At
every oil change. Use John Deere filter RE504836 or equivalent. Fuel
Filter Replacement (primary): 500 hours or when the water-in-fuel sensor
indicates water accumulation. Fuel Filter Replacement (secondary): 500
hours, concurrent with primary filter.
Valve Clearance (cold engine, hydraulic lash adjusters collapsed):
Intake: 0.014 in (0.36 mm). Exhaust: 0.018 in (0.46 mm). Note: Hydraulic
lash adjusters normally maintain zero clearance. This measurement is
only required after cylinder head service or when adjusting mechanical
lifters if the engine is fitted with a manual lash option (rare on
HF485; most have hydraulic adjusters). For engines with hydraulic
adjusters, no periodic adjustment is required.
Air Cleaner Service: Replace primary element when restriction indicator
shows 25 in H₂O (6.2 kPa) or at 1000 hours maximum. Do not clean or blow
out the paper element. Replace the secondary safety element every third
primary change. Coolant Replacement: 1500 hours or 2 years. Test SCA
concentration every 500 hours. Injector Service Interval: Inspect and
calibrate every 3000 hours. Replace nozzles at 6000 hours or if engine
exhibits rough running, excessive smoke, or increased fuel consumption.
Valve Lash Check (if equipped with manual adjustment): 1500 hours. Cold
engine only. Drive Belt (accessory): Inspect for cracks or glazing at
500 hours. Replace at 1500 hours or earlier if cracking is visible.
Turbocharger Inspection: Visual check of shaft axial play at 1500 hours.
Replace if play exceeds 0.030 in (0.76 mm) or if turbine blades show
erosion or contact marks.
Cylinder Head Bolts (M16), Stage 1: 75 lb-ft (102 Nm).
Cylinder Head Bolts (M16), Stage 2: 110 lb-ft (149 Nm).
Connecting Rod Bolts (M12): 43 lb-ft (58 Nm).
Main Bearing Cap Bolts (M14): 100 lb-ft (136 Nm).
Flywheel Bolts (M12, to crankshaft flange), Stage 1: 50 lb-ft (68 Nm).
Flywheel Bolts (M12, to crankshaft flange), Stage 2: 95 lb-ft (129 Nm).
Flywheel Housing Bolts (to block): 55 lb-ft (75 Nm).
Crankshaft Damper Pulley Bolt (center bolt): 130 lb-ft (176 Nm).
Camshaft Thrust Plate Bolts: 18 lb-ft (24 Nm).
Rocker Arm Shaft Bracket Bolts: 35 lb-ft (47 Nm).
Injector Clamp Bolts (hold-down): 22 lb-ft (30 Nm).
Common Rail Mounting Bolts: 18 lb-ft (24 Nm).
High-Pressure Pump Mounting Bolts: 25 lb-ft (34 Nm).
Oil Pump Mounting Bolts (to block): 18 lb-ft (24 Nm).
Oil Cooler Mounting Bolts: 25 lb-ft (34 Nm).
Water Pump Mounting Bolts: 30 lb-ft (41 Nm).
Thermostat Housing Bolts: 18 lb-ft (24 Nm).
Starter Motor Mounting Bolts (12V): 45 lb-ft (61 Nm).
Starter Motor Mounting Bolts (24V): 55 lb-ft (75 Nm).
Alternator Pivot Bolt: 40 lb-ft (54 Nm).
The John Deere 6068HF485 engine served in a broad range of off-highway
equipment categories, primarily in North American and European markets
from 2006 through 2014 before Tier 4 emissions requirements phased it
out.
Agricultural Tractors:
John Deere 7030 Series (e.g., 7630, 7730, 7830 models) as the base or
mid-range power option.
John Deere 8030 Series (e.g., 8330, 8430) for smaller chassis
configurations.
Self-Propelled Agricultural Equipment:
John Deere 6030 Series self-propelled forage harvesters.
John Deere 70 Series and 80 Series combine harvesters.
Industrial Equipment:
John Deere 244J, 304J, and 344J wheel loaders.
John Deere 410G and 510G backhoe loaders.
Wood chippers from Morbark, Bandit, and Peterson (as a power unit).
Stationary industrial compressors from Atlas Copco and Sullair.
Generator Sets:
John Deere 150-250 kVA standby generator sets (models 200 kW and 250 kW
ratings).
Prime power units for telecommunications towers and irrigation pumping
stations.
Marine Propulsion (limited): Small
workboats and river push boats using John Deere marine conversions with
closed-loop cooling.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
