John Deere 6125M

Single-fluid solution

Reliable and proven engine technology

 

John Deere 6M Series Tractors feature the reliable and proven PowerTech PVX engines.      

These air-to-air aspirated engines deliver constant power over a wide range of engine revolutions per minute (rpm) with a power bulge above rated power to provide good torque in demanding applications.

• Engines deliver a constant power range of percent with a power bulge of percent.
• High-pressure common rail (HPCR) fuel injection system and other key engine parts work together to sense engine load and then instantly respond as needed to pull through tough soil conditions.
• Engine rpm fluctuations are reduced to minimize the need to downshift the transmission.
• Fewer shifts result in less ground-speed variations, providing higher overall tractor productivity.
• To match the engine power characteristics and improve economy of operation, the rated engine speed is 2100 rpm.

The full-frame concept

Full-frame concept

The engine is an integrated part of the full-frame concept. The engine is connected to the frame using vibration-absorbing isolators. Further vibration reduction is achieved by utilizing a heavy-duty torsional damper in the Cardan shaft, coupling the flywheel to the clutch housing. This technique:

• Eliminates engine block stress, because the engine is no longer a structural part of the tractor.
• Reduces noise and vibration transfer to other tractor components.
  

 Four-valve cylinder head

• Positions the injector in the center of the piston and combustion chamber for even piston loads and mixing of fuel
• Maintains cooler head temperatures through a high rate of airflow
• Raises the air-fuel ratio while reducing internal operating temperatures for improved reliability and fuel efficiency
• Valves and replaceable valve-seat inserts are designed to minimize flow restriction (engine uses special powdered metal valve-guide inserts with impregnated lubricant for proper seating and to prolong wear)
• Offers excellent pull-through characteristics delivered by constant high torque
• Allows faster field operating speeds

There is improved lugging ability throughout the entire working range with significant productivity improvements at low engine rpm.

The intake manifold is located above the exhaust manifold.

• Location allows intake air to go directly down through the head with minimal turning to aid in engine breathing characteristics.

The engine width is not changed greatly, allowing for a narrow tractor hood and excellent row-crop visibility.

Injectors

 

Injectors deliver the same fuel pressure level to cylinders from the high-pressure common rail:

• Magnetic valve provides fast and precisely metered fuel injection.
• Six-hole nozzles give optimum spray patterns and fine fuel atomization.

Performance-matched fuel consumption delivers reduced fuel costs per acre.

HPCR fuel injection system and engine control unit (ECU)

Every PowerTech PVX engine utilizes the HPCR fuel system to supply fuel to injectors.          

The high-pressure fuel pump instantly responds to requirements for more or less fuel flow or pressure. The pressure is generated by the gear-driven piston pump. This electronically controlled and
high-pressure pump delivers pressure on demand according to the application requirements.

Benefits:

• HPCR delivering exactly the same fuel pressure level at all of the injectors
• High responsiveness under all load and speed conditions, which extends the engine working range to lower speeds, delivering more power and productivity in the field at outstanding fuel-saving engine speeds
• Performance-matched fuel consumption, delivering reduced fuel costs per acre

The ECU uses signal inputs from sensors and pre-programmed performance modeling to control critical engine functions such as:

• Fuel quantity
• Injection timing
• Air-to-fuel ratio
• Multiple fuel injections
• Amount of cooled exhaust gas recirculation (EGR)
• A host of other control parameters to deliver peak fuel economy and engine performance

Each injector is controlled individually by the ECU. The ECU turns the injector on and off during each firing cycle to control the fuel delivery into each cylinder. The ECU can sense engine speed and load changes at a rate of 100 times per second and respond instantly to them. Load and speed sensing allows each cylinder’s fuel delivery rate to be adjusted independently at the individual injector. With each injection cycle, the ECU can make the following adjustments on the go:

• Number of injections
• Fuel pressure in the common rail
• Start of injection
• Duration of injection

This management system is connected to the transmission, allowing the engine and transmission to respond simultaneously.

Cold-weather and high-altitude compensation are also precisely controlled for quality starts regardless of weather and proper power levels at high elevations.