Engine, PowerTech™ Plus 6.8L power ratings and specifications
John Deere 6.8L PowerTech Plus engine
 
PowerTech Plus 6.8L engine

PowerTech Plus 6.8L engine

All John Deere 7030 Series Tractors feature the reliable and proven 6.8 L (414 cu in.) engines. These air-to-air aftercooled engines deliver constant power over a wide range of rpm with a power bulge above rated power and excellent torque characteristics.
Model and horsepower outputs are shown in the chart below.

Model

Displacement

Rated PTO
hp

Rated engine hp
97/68 EC (ISO)

7630

6.8L
(414 cu in.)

140

175

7730

6.8L
(414 cu in.)

152

190

7830

6.8L
(414 cu in.)

165

205

7930

6.8 L
(414 cu in.)

180

220


Other horsepower ratings are included for reference to competitors' gross or engine only power ratings. There are several ratings systems used by other brands. John Deere uses the horsepower rating standard 97/68 EC, which is widely used in Europe for various regulations.
Engine performance characteristics
 
Ample torque rise 30 percent faster - Chart A

Ample torque rise 30 percent faster - Chart A

All 7030 Series Tractor 6.8L engines have a wide operating range of 1000-2100 rpm. Power comes on quickly as rpm increases for excellent load starting. Normal operating speeds provide plenty of reserve power to handle changing conditions both in the field and on the road.
 
These engines provide PTO horsepower bulge up to 10 percent and PTO torque rise up to 40 percent.
 
There are updated performance characteristics of the 6.8L engines that assure excellent performance in most any situation. Key engine features such as the Variable Geometry Turbocharger (VGT) and the 4-valve head provide the ability to bring on improved levels of the rate of torque rise and fuel economy.
 
PowerTech Plus engines reach peak torque quickly. In chart A, you can see when compared with previous models, all 7030 Series Tractors reach peak torque at 1600 rpm vs.1400 rpm. From
rated speed to peak torque the 7930 Tractor engine drops only 500 rpm and the 7920 Tractor engine will have to lose 800 rpm to reach peak torque. Dividing the rpm change from rated speed, it shows that a 6.8L engine will achieve peak torque at a 30% quicker rate than the models it replaces.
 
The operator of a 7030 Series Large-Frame Tractor is sure to notice the resulting tractor performance gains made with plenty of torque and overall power. Improved performance load starting, pulling through tough spots or transporting will be appreciated. Greater overall torque and faster torque response will be noticed, especially when making manual range changes and potentially restarting tractor motion from a stop.

PTO torque rise and power bulge
 
Torque rise comparison-7930/7920 Tractor - Chart B

Torque rise comparison-7930/7920 Tractor - Chart B

PowerTech Plus engines reach peak torque quickly.  In chart B,  it can be seen when compared with any of the 7020 Series Tractor, that peak torque is reached at a very usable 1600 rpm vs.1400 rpm in the previous models.  The chart indicates a comparison between the 7920 and 7930 Tractor from rated speed at 2100 rpm.  To reach peak torque, the 7920 drops only 500 rpm and the 7920 has to lose 700 rpm.  Dividing the rpm change, it shows that the 6.8L engine will achieve peak torque at a 30% quicker rate than the models it replaces.
Reduced fuel consumption potential
 
There are several improved designs in all of the 7030 Series Large-Frame Tractors that have made a favorable impact to fuel economy.  All of these design changes work together to provide a more efficient use of engine power, resulting in less consumption in some models and same performance in others.
Fuel economy improvement up to 5% - Chart C

Fuel economy improvement up to 5% - Chart C

In Chart C,  there is an "equation" for up to 5% economy improvement.  Several factors are involved in this via design changes in several areas - the engine, cooling system, and drivetrain components.
The engine, with features like 4-valve-per-cylinder head, variable geometry turbocharger, and single-injector control with the high-pressure common rail fuel system provide economy improvements over the 8.1L engine of the past models. 
The cooling system has an electronic control of the cooling fan.  The viscous fan has the ability to vary the required speed to keep the engine and tractor systems operating at the appropriate temperature.   Cooling fans take significant energy to operate. Precise control of the speed provides a potential to save fuel.    
There has been a reduction in drivetrain windage or "drag" internal to a tractor as it is moving in the field or at transport speeds.  Many components have been redesigned to reduce the windage and improve how much power is lost.  Improvements mean more power is made available to the drawbar, hitch, and PTO. 
There are additional fuel saving potentials with the John Deere IVT™ (Infinitely Variable Transmission). This transmission has capabilities to automatically adjust the engine speed or ground speed to the load encountered.   See the transmission section for more information on how "+ More" can be an additional benefit.  
Engine basic specifications
 

General specifications

Manufacturer/type John Deere PowerTech Plus 6.8L 4-valve-per-cylinder engine
Rated speed 2100 rpm
Type Diesel, in-line, 6-cylinder, wet-sleeve with 24 valves in head
Aspiration Variable geometry turbocharger with air-to-air after-cooling and exhaust gas recirculation
Filter, engine air Dual-stage with engine cooling fan aspiration
Displacement 6.8 L (414 cu. in.)
Bore and stroke 106 mm (4.19 in.) x 127 mm (5.00 in.)
Compression ratio 17.0 : 1
Lubrication Full-pressure, full-flow filtration with bypass
Filter, oil Replaceable spin-on cartridge-type oil filter
Fuel system (type) Electronically-injected and governed, high-pressure common rail,
electric fuel transfer pump provides self-priming
Filter system Two-stage with water separator and service required indicator light
Filter, primary 30-micron replaceable cartridge
Filter, secondary 2-micron spin-on element
  • When compared to the 8.1 L engine used in 7820 and 7920 Tractor models, the cylinder bore was 10 mm (.37 in.) larger and stroke is 1 mm (.04 in.) longer that the 6.8 L engine.
  • The engine design utilizes metric-sized components and hardware for ease of service and commonality with the remainder of the tractor.
Oil and coolant drain intervals
 
The large oil sump attached to the frame-mounted engine provides oil capacity for long, 250-hour change interval (500 hours when John Deere PLUS-50™ oil and a John Deere oil filter are used.)
 
There is special engine break-in oil used at the factory to assure proper seating of all components. That oil should be changed after the first 100 hours of operation.
 
To further reduce maintenance requirements, long-life coolant/antifreeze with coolant conditioner is used as the factory fill on all 7030 Series Tractors. The first required change interval is at 3 years or 3000 hours. If John Deere Cool-Gard™ is used as replacement fluid, intervals can be extended to 5 years or 5000 hours. The only thing that is required on an annual basis for your cooling system is a simple test of coolant conditioner.

Oil and coolant capacities
 

System

 Capacity

Cooling system

26.5 L (28 qt.)

Crankcase capacity with filter

26 L (27.5 qt.)

Torque to rpm charts
 
The following charts represent relative torque comparisons between 7020 and 7030 Series Tractors at various engine rpm.   In each of the charts below, you will see the following key differences:
 
  • Increased levels of torque are available with the horsepower increase present on each model
  • Engine rpm at rated speed is 2100
  • Peak torque is at 1600 rpm
  • Torque rise rate is greater than previous models
  • At rated rpm each 7030 Series model has more torque than previous models
  • The data comes from "bare" engine specifications
7630 Tractor torque curve

7630 Tractor torque curve

7730 Tractor torque curve

7730 Tractor torque curve

7830 Tractor torque curve

7830 Tractor torque curve

7930 Tractor torque curve

7930 Tractor torque curve

Base Equipment On : 7630, 7730, 7830, 7930 Tractors
 
Last Updated : 09-Jul-2010