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Duramax
Diesel |
The Isuzu - General Motors Story
A look at where this team came from and where it's headed!
* Over 60 different diesel engine models.
* Fuel efficient - Clean.
* Powerful beyond expectation.
* Durable, reliable diesel power
Isuzu, the global engine producer with production facilities in North America,
Turkey, Poland, Japan, China, and Thailand.
Isuzu has focused on providing clean, reliable, durable diesel power for over 60
years. The Isuzu diesel is everything a diesel engine can be, and more.
 In
1936 Isuzu launched its first diesel power plant. Now, 66 years later, Isuzu is
supplying well over 300,000 diesel engines yearly to General Motors.
GM and Isuzu entered into a capital agreement in 1971. That relationship
continued to flourish and grow, and in 1997 GM and Isuzu agreed that Isuzu would
become the global C.O.E. (Center of Expertise) for diesel engine development
within General Motors.
One year later, GM and Isuzu formed a joint venture for the development and
production of the 6.6 liter Duramax Diesel.
The Duramax 6600 Turbo Diesel was the product to meet a rather bold goal.
That goal was to design, build, and deliver the most powerful diesel engine for
use in a full size, light duty pickup truck.
Today, General Motors' new line of heavy-duty pickup trucks are consistently
increasing diesel engine market share. The Duramax 6600 Turbo Diesel was voted
as one of "Ward's Communications" 10 best engines for the year 2001.
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The
Duramax Diesel 6600 is produced in Moraine, Ohio. The GM / Isuzu relationship is
growing stronger daily, with a commitment from both companies to remain
dedicated to continually improving the quantity and quality of GM diesel powered
pickup trucks. In terms of diesel engine production, Isuzu is poised to become
the dominant diesel engine provider in North America.
When it comes to diesel engines, General Motors relies on Isuzu to provide the
most technologically advanced diesel power. The introduction of the new Duramax
Diesel 7800 is showing the world that together they can design and build
competitive, powerful, and reliable diesel engines for use around the world.
GM
is committed to using Isuzu diesel power in all its trucks. Offering an
additional advantage for GM customers of "One Stop Shopping" for all parts,
service, maintenance, and repairs. The GM dealer is certified, equipped, and
ready to handle all Isuzu maintenance, repair, and service needs.
This eliminates the GM medium duty
truck customers having to watch their GM trucks head out the door of the GM
dealership and down the road to a separate, independent diesel engine service
center. This new Duramax Diesel 7800 is now in Chevrolet Kodiak, GMC Topkick,
and all GM's T-series.
The Duramax Diesel 7800 is an "Inline
6" commercial truck diesel, currently used in well over 300,000 trucks
worldwide.
GM's confidence in the Duramax Diesel
7800 is high enough to make it the only engine available for the 2003 GMT 560
T-series Tilt Cab that will be available in early 2003.
The Duramax Diesel 7800 is available in
horsepower configurations ranging from 200 HP all the way up to the "High
Torque"
275 HP Version
Duramax 7800 - 200 HP Version
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Duramax
Diesel 7800 Specifications |
| Duramax
7800 |
200
Horsepower |
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Displacement |
7.8 Liters
/ 475.9 Cubic Inches |
| # of
Cylinders |
6 In Line |
| Bore |
4.53 Inches |
| Stroke |
4.92 Inches |
| Compression
Ratio |
16.0 : 1 |
| Dry Weight |
1180 pounds |
| Fuel Grade |
# 2 Diesel |
| Engine
Power |
200 HP @
2200 RPM |
| Torque |
520 pound
Feet @ 1450 RPM |
| Governed
full load setting |
2400 RPM |
| No Load
Governing speed |
2550 RPM |
| Low-Idle,
Curb Idle |
600 RPM |
Duramax 7800 High Torque -
275 HP Version
This engine uses the exact same displacement and compression ratio as listed
above, and has the same fuel grade requirements. It is tuned to produce the
power ratings shown below.
Engine Power 275 HP @ 2200 RPM
Torque 860 Pound feet @ 1450 RPM
The Governed full load setting, no load governing speed, and curb idle remain
the same as the 200 Hp Version listed above. The power range includes 200, 215,
230, 250, and the High Torque 275 Horsepower versions.
Duramax Diesel
10 Keys:
The 10 technological advantages that distinguish the Duramax Diesel
according to Isuzu:
Ladder Frame Construction:
(cylinder block)
Light Weight
High Rigidity
Reduced noise
Reduced Vibration |
High Pressure Fuel Injection
Low Noise Level
Low Vibration
Performance
Fuel Economy |
Precision
Machined Fit Sleeve
Serviceability
Durability / Reliability |
Nitrided Crankshaft
Durability /
Reliability |
Overhead
Cam Layout (OHC)
Performance
Low emissions
Good Fuel Economy |
Viscous Rubber Type Damper
Low Noise
Low Vibration |
4-Valve Layout
Performance
Low Emissions
Good Fuel Economy |
Axial Oil Seals
Durability /
Reliability
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Pistons with Cooling Channel
Durability /
Reliability
Performance |
Oil
Cooler w/ Temperature Regulator Valve
Fast Warm Up. |
The most important part of any engine
is the cylinder block. To be durable and reliable, it must be very strong,
especially in the "Bottom End", or crankshaft main bearing webs. A strong bottom
end determines the "rigidity" of the Powertrain, including the transmission.
Duramax Nitrided Crankshaft
Isuzu research indicates that "Ladder Frame Construction" of the cylinder block
provides significant increases in both reliability and durability. It minimizes
the cylinder block bending moment and counters the vibration mode that tries to
deform the main bearings. Remember, the main bearings are responsible for
converting all the combustion energy from up-and-down motion to rotational
motion.
Accomplishing that requires a significant amount of strength and rigidity in the
main bearing area. Ladder frame construction provides that strength.
Furthermore, the increased rigidity significantly improves Powertrain noise and
vibration characteristics (NVH) and contributes greatly to exceptional
durability. Experimental model analysis and FEM frequency response analysis
contributed to the development of the single piece construction used for the
cylinder block's bottom wall. This wall serves as the both the crankcase, and
the crankshaft support area-bearing cap to further increase the rigidity of the
crankshaft support area.
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The next area of quality is the
precision machining quality found in every Duramax. The "Precision Machined Fit
Sleeves" of the Duramax offer several benefits. Service personnel will be
pleasantly surprised with the ease of sleeve replacement, even after long
periods of engine use. The precision fit sleeves offer a major cost savings
during the engine overhaul, eliminating the need for cylinder reboring. The
Duramax 7800 cylinder bore configuration offers the advantages of both "Parent
Bore" and "Wet Liners" while avoiding the pitfalls traditionally associated with
each. Traditionally, camshafts, pushrods, and
tappets were all part of a diesel engine in the Duramax power range. This
classic valve train arrangement does lend itself well to designers
tasked with meeting rigorous government emission standards and customer needs of
the 21st Century.
Space that could be used for increasing
engine block rigidity, or more effective valve porting (to improve engine
breathing), was instead dedicated to the valve train and its operation.
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By going to an overhead cam design with
four valves per cylinder, and roller rocker arms in direct contact with the
camshaft, the need for tappets and pushrods was eliminated.
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| Duramax Roller Rocker Arm Assembly
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Duramax
Roller Rocker Arms |
Duramax
Roller Camshaft |
The designers realized the ability to substantially increase block rigidity
while providing engine symmetry, with the fuel injection nozzles located in the
center of the cylinder.
This gives more even fuel distribution, which reduces black smoke, Nox, and
particulate matter. This strategic injector placement results in better fuel
distribution in the combustion chamber, resulting in more effective combustion
chamber swirl, for smoother, more efficient operation. This design also
contributes to greatly reduced NVH (Noise, Vibration, and Harshness) and
exceptional durability.
As power and performance go up, so do internal engine temperatures. Efficient,
effective temperature control throughout the engine is critical. Without proper
cooling, engine power drops, noise levels increase, blow-by gases increase, and
eventual piston failure and / or seizing occurs in the cylinder bore.
To end that, the Duramax is designed with high performance cooling throughout,
with special attention to oil cooling. But nowhere is controlling more critical
that at the pistons. In fact, the ability to lower and control the piston
thermal load is key to durability and reliability in the high output diesel.
Piston Cooling Jet
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High piston temperature can cause
material strength to drop. It can also lead to component cracking, oil
carbonizing in the ring grooves, rings sticking, and piston to bore seizing. The
Duramax is designed to control piston temperature through a number of design
features, including proper sized cooling channels, optimum
Duramax piston
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cooling system architecture,
ensuring temperature balance between oil inlets and outlets, and maintaining the
correct oil volume. The Duramax 7800 uses a "Piston Cooling Jet" connected to
the main oil gallery. It injects oil into the piston oil cooling channels to
cool the piston and lubricate the piston pin.
Fuel Injection System
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Duramax 7800 Denso Common Fuel Rail.
The Duramax 7800 uses a Denso common rail fuel injection system with pilot
injection. The common rail design allows the engine's computer to independently
control fuel injection, which allows for optimizing emissions and power. This
common rail fuel system greatly increases fuel economy, and significantly
reduces NVH.
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Denso Fuel Pump
This new fuel injection system is further enhanced by the "Closed Loop" fuel
control system's self-diagnosing feature. This feature monitors engine
conditions like engine speed, accelerator pedal angle, coolant temperature, and
others, and feeds the data back to the fuel injection algorithm calculations.
The results are greatly increased fuel economy, power, and responsiveness with
reduced emissions.
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Duramax 7800 Pilot injector The pilot injection system injects a small amount of fuel just prior to the
conventional fuel injection pulse. Pilot injection helps the Duramax 7800 to
lower NOx emissions, improve cold starting and cold responsiveness, reduced
knock and noise, and overall increased combustion efficiency.
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Duramax 7800 Combustion chamber showing
4-valve layout with fuel injector in center for increased efficiency.
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General Motors and Isuzu have shaken up the light truck world with the
introduction of the Duramax 6600 and the Duramax 7800. These engines will meet
all proposed 2004 model year diesel engine emission requirements. You can be
sure that these technically innovative products will increase the competition in
this arena tremendously as North America turns to diesel power for all it's
needs.
I thought you would enjoy one last picture. Happy Motoring!
Sam Memmolo
 The
BRUIN
Pictures and some information above supplied by General Motors and Isuzu.
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