John Deere 6068HF150 Specifications
| Engine Model: John Deere PowerTech 6068HF150 |
| Engine Type: 4-stroke in-line 6-cylinder turbocharged liquid-cooled diesel |
| Total Displacement: 415 cu.in (6.8 L) |
| Rated Engine Power: 192-251 Hp (143-187 kW) at 1800-2200 rpm |
| Fuel System Type: Direct injection |
____________________________________________________________________________________
The John Deere 6068HF150 is a 6.8-liter, inline
six-cylinder diesel engine from the PowerTech 6068 series, configured
for industrial and generator set applications. This engine operates as a
"Lesser Regulated" unit, meaning it was produced without formal
emissions certification or met Tier 1 standards depending on the
application year and regional requirements. The “HF” designation
indicates a high-fuel-efficiency configuration with a mechanical fuel
system.
Unlike later electronic variants, the HF150 employs a mechanical
governor with a rotary fuel pump, providing straightforward field
serviceability. The engine uses turbocharging combined with an
air-to-air aftercooler (ATAAC) to increase air density for improved
combustion efficiency. Engineers designed this powerplant for
intermittent industrial duty at 2200-2400 rpm and continuous generator
operation at 1800 rpm. Power outputs span 143 to 157 kW (192-211 hp) for
industrial applications, with generator stand-by ratings reaching 187 kW
(251 hp).
The 6068HF150 incorporates replaceable wet-type cylinder liners for
efficient heat dissipation and simplified overhaul. A full-pressure
lubrication system maintains component protection across varying load
conditions. The engine accepts either 12-volt or 24-volt electrical
configurations, with corresponding battery cold cranking amperage
ratings of 800 CCA or 570 CCA.
The John Deere 6068HF150 is an in-line, four-cycle, six-cylinder diesel
engine. Total displacement measures 6.8 liters, equivalent to 415 cubic
inches. Bore is 106 mm (4.17 in) with a stroke of 127 mm (5.00 in),
producing an undersquare configuration that prioritizes torque
development at lower rotational speeds. The compression ratio is fixed
at 17.0:1. Aspiration uses a turbocharger combined with an air-to-air
aftercooler (ATAAC), which reduces intake air temperature before entry
into the cylinders. The firing order is 1-5-3-6-2-4. Industrial
intermittent power ratings at 2200 to 2400 rpm span 143 to 157 kW,
equivalent to 192 to 211 hp.
Generator set stand-by power at 1800 rpm for 60 Hz operation is 187 kW
(251 hp). Generator set prime power at the same speed is 168 kW (225
hp). Peak torque values range from 749 to 771 Nm, corresponding to 552
to 569 lb-ft, achieved between 1300 and 1400 rpm. High idle speed,
governed and no-load, varies by configuration but generally sits between
2550 and 2650 rpm. Low idle speed is set to 850-950 rpm for industrial
applications.
The cylinder block is constructed from high-strength gray cast iron with
a deep-skirt design extending below the crankshaft centerline. This
architecture provides exceptional torsional stiffness and vibration
damping. The block uses replaceable wet-type cylinder liners, each
manufactured from centrifugally cast iron. Each liner contacts engine
coolant directly along its full exterior length, ensuring efficient heat
dissipation from the combustion zone.
The wet liner design permits individual cylinder replacement without
block reboring, reducing overhaul costs and downtime. Each liner
features a flanged top that seats against a precision-machined
counterbore in the block deck, with multiple sealing rings at the lower
end. Cylinder liners are finish-honed to a cross-hatch pattern that
promotes oil retention for piston ring sealing.
The cylinder block incorporates seven main bearing webs with reinforced
bulkheads. Cast internal oil galleries direct pressurized lubricant to
all main bearings, connecting rod bearings, camshaft bearings, and
piston cooling jets. Cooling passages surround each cylinder liner along
the full stroke length. The block includes mounting pads for the
mechanical fuel injection pump on the left side (viewed from the
flywheel end). A front timing gear housing is cast integrally with the
block.
A single cast-iron cylinder head spans all six cylinders in a cross-flow
design. Intake ports occupy one side of the head, exhaust ports the
opposite side. The valvetrain operates as an overhead valve (OHV)
configuration with two valves per cylinder - one intake and one exhaust
- for a total of 12 valves. A camshaft located within the cylinder block
actuates the valvetrain.
Pushrods transfer motion through vertical bores in the cylinder head to
rocker arms mounted on a steel shaft. Hardened valve seat inserts are
pressed into the cylinder head, with exhaust seats manufactured from a
nickel-chromium alloy for high-temperature resistance. Valve guides are
replaceable cast-iron sleeves pressed into the head. Intake valve
diameter is 45 mm (1.77 in).
Exhaust valve diameter is 41 mm (1.61 in). Valve lash adjustment uses a
screw-and-locknut mechanism on each rocker arm. The cylinder head gasket
is a multilayer steel (MLS) design with etched sealing beads around each
cylinder bore, oil galleries, and coolant passages. Six head bolts per
cylinder provide even clamping force distribution. No pre-combustion
chambers exist in this head, as the engine uses direct injection with a
bowl-in-piston design.
The fuel system uses a mechanical governor with a rotary
distributor-type fuel pump, manufactured by Stanadyne or Bosch depending
on the production year. A mechanical gear-type lift pump mounted on the
cylinder block draws fuel from the tank through a primary spin-on filter
and water separator. The lift pump supplies fuel at low pressure to the
injection pump.
The injection pump contains a high-pressure rotor, an internal vane-type
transfer pump, and a mechanical centrifugal governor that regulates fuel
delivery based on engine speed and load. The governor responds to a
throttle lever connected by cable or linkage to the operator's control.
Injection timing is set manually by rotating the pump mounting flange
and locking it at the calibrated position. The pump delivers
high-pressure fuel through six steel injection lines to the injectors.
Each injector is a hole-type, pencil nozzle with multiple orifices. The
electric fuel shutoff solenoid operates on either 12V or 24V depending
on the electrical system specification. When energized, the solenoid
opens the fuel supply passage inside the pump. When de-energized, a
spring returns the shutoff valve to the closed position, stopping the
engine. A fuel return line routes excess fuel and leakage back to the
fuel tank.
The lubrication system operates as a full-pressure, forced-feed design
using a gear-type positive displacement pump. The pump is mounted on the
front timing gear cover and driven directly by the crankshaft gear. Oil
is drawn from the oil pan through a pick-up tube fitted with a coarse
mesh strainer. Two oil pan capacity options exist. The standard
high-capacity pan holds 18 liters, equivalent to 19 U.S. quarts.
Total engine oil capacity, including the filter, is 19 liters (20 U.S.
quarts). A spin-on full-flow oil filter is mounted externally on the
block. An optional bypass oil filter can be installed for extended
service intervals. Piston cooling jets direct oil streams to the
underside of each piston crown for thermal management. A pressure relief
valve bypasses excess oil flow back to the sump.
The system supplies lubricant to the seven main bearings, six connecting
rod bearings, camshaft bearings, rocker arm assembly, timing gears, and
the turbocharger center housing. Oil pressure at rated speed is
maintained between 275 and 345 kPa (40 and 50 psi). The oil pan
incorporates a drain plug with a magnetic tip to capture ferrous
particles.
The cooling system is pressurized and thermostatically controlled, using
a centrifugal water pump driven by the front accessory drive belt.
Engine coolant capacity, excluding radiator and external hoses, is 11.3
liters, equivalent to 12 U.S. quarts. The system operates under a
pressure cap rated to maintain coolant liquid phase up to elevated
temperatures.
A wax-pellet thermostat located in a housing on the front of the
cylinder head controls coolant flow. The thermostat begins to open at
82°C (180°F) and reaches fully open position at 94°C (202°F). When the
thermostat is closed, coolant recirculates within the engine block and
head for rapid warm-up. After opening, coolant flows through the
radiator for heat rejection.
The water pump circulates coolant through passages cast into the
cylinder block surrounding each wet liner, then up through the cylinder
head, past the exhaust valve seats, and out to the thermostat housing.
The ATAAC system operates as a separate cooling circuit. Charge air from
the turbocharger passes through an air-to-air heat exchanger mounted in
front of the radiator, with engine coolant never entering the charge air
cooler. A coolant filter with corrosion inhibitor is standard equipment
on many industrial configurations.
| Intake and Exhaust Systems |
Air Intake System: Ambient air passes through a dry-type, two-stage air
cleaner before entering the turbocharger compressor. Compressed air
exits the turbocharger at elevated temperature, then travels through a
hose to the air-to-air aftercooler. After cooling, the dense charge air
enters the intake manifold for distribution to each cylinder.
Exhaust System: A pulse-type cast-iron exhaust manifold collects gases
with cylinders paired to maintain exhaust energy to the turbocharger
turbine. The manifold is flanged for connection to the turbocharger
turbine inlet housing. A single exhaust outlet exits the turbine
housing.
Two electrical configurations are available. The 12-volt system uses a
battery rated at 800 cold cranking amps (CCA). The 24-volt system uses a
battery rated at 570 CCA. The starter motor is a gear-reduction type
mounted to the flywheel housing. The alternator is belt-driven, with
outputs ranging from 65 to 120 amps depending on the OEM specification.
Glow plugs or an intake air grid heater assists cold starting. An
electric shutoff solenoid mounted on the injection pump provides engine
stop control.
Gear Train: The front timing gear system uses all steel gears. The
crankshaft gear drives the camshaft gear, injection pump gear, water
pump gear, and an auxiliary drive gear. The standard auxiliary drive can
power hydraulic pumps or other accessories.
Engine Governor: A mechanical, centrifugal flyweight governor is
integrated into the injection pump. The governor maintains engine speed
under varying loads. The operator controls a throttle lever connected to
the governor spring. The system includes both low-idle and high-speed
governor limits.
Engine length measured from the front gear cover to the flywheel housing
mounting face is 1123 mm (44.2 in). Width measured across the widest
points, including the injection pump and exhaust manifold, is 623 mm
(24.5 in). Height measured from the oil pan rail to the top of the
rocker arm cover is 1015 mm (40.0 in).
Dry weight of the complete engine, including the flywheel, turbocharger,
ATAAC connections, injection pump, alternator, and starter motor, but
excluding oil and coolant, is 550 kg (1213 lb). The weight with a full
oil charge and coolant adds 40 kg (88 lb). Shipping weight on a pallet
with protective packaging is 600 kg (1323 lb).
Engine Oil: High-capacity pan: 18 l (19 U.S. qt). Total with filter: 19
l (20 U.S. qt). Oil change interval: 250 hours (industrial), 500 hours
(genset with oil analysis). Recommended grade: SAE 15W-40. Oil Filter:
Spin-on full-flow type. Replace at every oil change. Coolant: Engine
capacity (excluding radiator): 11.3 l (12 U.S. qt). Change interval:
2000 hours or 2 years. Coolant Filter: Replace at every coolant change.
Valve Lash (Cold): Intake: 0.36 mm (0.014 in). Exhaust: 0.51 mm (0.020
in). Inspection interval: 500 hours. Valve Lash (Hot): Intake: 0.46 mm
(0.018 in). Exhaust: 0.61 mm (0.024 in). Air Cleaner: Dry cartridge
type. Service when restriction indicator shows 5 kPa (20 in water).
Thermostat: Begins opening at 82°C (180°F). Fully open at 94°C (202°F).
Low Idle Speed: 850 to 950 rpm depending on application. High Idle Speed
(No Load): 2550 to 2650 rpm. Injector Service: Check opening pressure
every 1500 hours. Battery (12V system): 800 CCA minimum. Battery (24V
system): 570 CCA minimum. Fuel Filter: Primary spin-on with water
separator. Replacement interval: 500 hours. Fuel Filter (Secondary):
Replace at 500 hours.
Cylinder Head Bolts (M16 x 2.0), Stage 1: 100 Nm (74 lb-ft).
Cylinder Head Bolts (M16 x 2.0), Stage 2: 250 Nm (184 lb-ft).
Connecting Rod Cap Bolts (M12 x 1.75): 115 Nm (85 lb-ft).
Main Bearing Cap Bolts (M14 x 2.0): 135 Nm (100 lb-ft).
Flywheel Bolts (M12 x 1.5): 115 Nm (85 lb-ft).
Crankshaft Damper Bolt (M20 x 1.5): 300 Nm (221 lb-ft).
Camshaft Thrust Plate Bolts: 25 Nm (18 lb-ft).
Rocker Arm Shaft Support Bolts: 35 Nm (26 lb-ft).
Rocker Arm Adjustment Lock Nut: 20 Nm (15 lb-ft).
Valve Cover Nuts: 12 Nm (9 lb-ft).
Injection Pump Mounting Nuts: 25 Nm (18 lb-ft).
Injection Lines (High Pressure): 30 Nm (22 lb-ft).
Injector Clamp Bolts: 28 Nm (21 lb-ft).
Oil Pan Drain Plug: 45 Nm (33 lb-ft).
Starter Motor Mounting Bolts: 45 Nm (33 lb-ft).
Turbocharger Mounting Nuts: 40 Nm (30 lb-ft).
Thermostat Housing Bolts: 25 Nm (18 lb-ft).
Water Pump Mounting Bolts: 25 Nm (18 lb-ft).
Alternator Pivot Bolt: 45 Nm (33 lb-ft).
The John Deere 6068HF150 engine serves across multiple equipment
categories requiring non-emissions-certified or Tier 1-compliant power.
Agricultural Equipment: Older John Deere 7000 and 8000 Series tractors
produced before stricter emissions regulations. Selected models of the
8030 Series. Generator Sets: Stand-by and prime power generators rated
at 150-200 kW output. Popular in 187 kW (250 kVA) stand-by sets for
commercial buildings.
Construction Equipment: John Deere 644G and 744G wheel loaders. John
Deere 772G motor graders in certain markets. Industrial Equipment:
Hydraulic power units for stationary machinery. Irrigation pumps for
agricultural water systems. Rock crushing and screening equipment.
Marine: Auxiliary power generators on workboats and small commercial
vessels. Compressor Drives: Stationary air compressors for industrial
facilities. This engine also appears in unattended pumping stations
where mechanical fuel system reliability is preferred over electronic
systems.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
