Class Intro.ppt 1
ACERTTM Technologyfor Off-Highway C9 Engines
This presentation covers the mechanical changes for the C9 off-highway engine using ACERT technology.
Class Intro.ppt 2
ACERT Technology• What does ACERT stand for? • What is ACERT Technology?• How is ACERT Technology Different?• What does ACERT Technology look like?• How does ACERT Technology work?• What are the advantages of ACERT
Technology? • Is extra maintenance required?
Class Intro.ppt 3
ACERT™ Nomenclature
Lack of a hyphen in the model number indicates an ACERT technology engine:
•C-9 is NOT an ACERT technology engine•C9 IS an ACERT technology engine
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ACERT Technology
What does ACERT stand for?AdvancedCombustionEmissionsReductionTechnology
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What is ACERT Technology?
“ACERT technology is a series of evolutionary, incremental improvements that provide a breakthrough engine technology built on systems and components that have been developed by Cat with proven reliability.”
John Campbell, director of on-highway engine products, Caterpillar Power Systems Division
So, what is ACERT technology?
In a recent press announcement, John Campbell, director of on-highway engine products -- Caterpillar Power Systems Division, described it this way, “ACERT technology is a series of evolutionary, incremental improvements that provide a breakthrough engine technology built on systems and components that have been developed by Cat with proven reliability.“
As technicians, trainers, technical communicators or whatever engine related job best describes each of us, it is reassuring to know that although we are dealing with breakthrough technology, it is based on a familiar platform.
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What is ACERT Technology?
• Multiple technologies• Varies by engine family• Varies by engine application
• Medium duty – specs, changes, new design
• Heavy duty – specs, changes, new design
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C9 ACERT
This presentation covers the core C9 ACERT engine as used in various machine applications.
Class Intro.ppt 8
Performance Ratings
kW @ 1800 to 2200 rpm
Off Highway Rating
205A224 B242260
C
279D
Class Intro.ppt 9
Power Band Performance
1300 1500 1700 1900 2100RPM
POW
ER
ABCD
2200 rpm provides• Widest operating
range• Easiest match in
changeover 1800 rpm provides• Best fuel economy• Best heat rejection • Less noise
* Operating speeds dependent on rating
Class Intro.ppt 10
Design Strategy
Based on proven C-9 Tier 2 Stage II engine
Proven reliability with thousands in operation
Easy changeover to new emissions regulations
ACERT technology is evolutionary rather than revolutionary. Many ACERT features have already been proven out through years of experience in the field. New uses of established technology is a key feature of ACERT technology.
Class Intro.ppt 11
Design Strategy
Improved design• ACERT technology • Increased PCP (Peak
Cylinder Pressure) capability
• HEUITM fuel system• ADEMTM 4 control unit
Improved performance, Tier III emissions compliance and noise reduction were key goals for the C9 machine ACERT engine.
Class Intro.ppt 12
Development
Improved designs• Piston, rings, liners• Connecting rods• Modified C9 block• HEUI injector• Valves, springs, seats• Cam lobes & bearings• Rod bearings
New designs•Cylinder head •Dual PTO’s•Front housing for HEP 10•ADEM 4 ECM
Leveraging proven components of the current C-9 has helped the C9 gain an advantage right out of the box.
Class Intro.ppt 13
Design Strategy
• Increased compression ratio• C9 - 17:1 compression ratio
• Component changes to increase peak cylinder pressure capability
• Improves cold start characteristics• Improves white smoke clean up time• Optimizes ACERT performance
The key feature of ACERT technology is control of emissions formation in the combustion chamber. One of the keys to this is the change in compression ratio to 16.5:1. Besides reduction in emissions, the cold start time is improved and cold starts down to –9 deg. C (16 deg. F) are possible without ether assist.
Class Intro.ppt 14
Validation Strategy
Rigorous endurance testingOver 40,000 hours per modelSpecialized tests include:• Thermal abuse• Cold start qualification• Over speed qualification• Crankshaft structure• Head / block structure• Emissions certification
All machine ACERT technology engines have been extensively tested to ensure reliable out of the box performance.
Class Intro.ppt 15
Multiple Injection Capability
HEUI and ADEM 4 • Variable injection
timing• Electronic control of
injected quantity• Optimized fuel
injection pressures• Transient control for
both speeds and loads
One of the key features for the C9 is the use of the HEUI-B injector and A4 (ADEM4) control unit. These fuel system changes give much greater flexibility with fuel injection timing, rate shaping and multiple injection capability.
Class Intro.ppt 16
Fuel System
Hydraulic Electronic Unit Injector• Proven design - millions in operation• Exclusive Cat technology • Common injector to C7
Enhanced design• Multiple injections• Rate shaping capability• Improved combustion
The HEUI-B injector is capable of multiple injections shots during a single combustion event. Based on operating conditions and demands, the ADEM4 ECM determines the number of injections and the injection rate that gives optimum performance and emissions. The core injector (HI-315B) is shared with the C7 engine.
Class Intro.ppt 17
HEUI DevelopmentHEP-10 pump replaces
HEP-8 for improved performance and reliability
HI315B injector has increased capabilities and is common with C7
Important improvements in the HEP (High Efficiency Pump) oil pump work in conjunction with the revised injector.
Class Intro.ppt 18
Larger HEUI Pump
Larger displacement pumpHigher rail pressure capabilityLarger reservoir
The C7 / C9 have a variable delivery HEUI Pump with an integrated electro-hydraulic control valve. An earlier version of this pump is used on the 3126E truck and C-9 industrial engines. The C7/C9 pump is essentially a bored and stroked version of the earlier pump, capable of 10 cc’s volumetric output per revolution versus the earlier pump's capability of 8 cc’s per revolution.The C7/C9 pump has 28MPa (4060 psi) relief valve pressure vs. 26MPa (3770 psi) for the earlier pump. It also has a larger capacity reservoir. Visually, this is the most distinctive feature. There are some other internal differences that support this higher pressure and higher displacement capability, but there is minimal new content due to design carryover.
Class Intro.ppt 19
HEUI Pump Drive
31 or 36 tooth drive gear for C9 HEP 10 pump
Cast iron mounting flange
The C9 may have either a 36 tooth or 31 tooth drive gear, depending on the application and oil flow requirements. All HEP10 pumps utilize a cast iron mounting flange to handle the increased bearing loads due to higher operating pressures (28 MPa) when compared to the HEP8 (26 MPa).
Class Intro.ppt 20
HEUI PumpVariable displacement pumpDisplacement control vs. pressure controlIncreased reliability
Because the pump has variable volume delivery, the system only pressurizes the volume of oil that is needed for engine operation. This results in a 1% to 5% bsfc improvement on the engine as compared to the fixed volume per revolution pump used on earlier HEUI engines.This pump uses a port-metering principle to regulate the volume of pressurized actuation oil. This is similar to the sleeve metering method used in earlier fuel systems. There is a fixed angle rotating drive plate. The pump group does not rotate. With over 20,000 endurance hours on the C7/C9 pump, and over two years of field experience on the pump used on the C-9 and 3126E.Endurance testing was performed at 120% of rated conditions, with cyclic and steady state testing at performed at 110 Degrees C. Manufactured oil, simulating used engine oil, was used for durability testing.
Class Intro.ppt 21
Port-meteringPiston Motion
Sleeve Position (controlled by actuator)
Zero Effective Stroke
Full Effective Stroke
Effective stroke begins at port closing
The sleeve position is controlled by the actuator. The piston is moved into and out of the stationary barrel assembly by the rotating swash plate.
Maximum volume is achieved when the sleeve is covering the bleed port in the piston body during the full stroke of the piston into the barrel. This is referred to as the “full effective stroke”.
Minimum volume is achieved when the sleeve is not covering the bleed port in the piston body during the full stroke of the piston into the barrel. This is referred to as the “Zero effective stroke”.
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Fuel Transfer Pump
The fuel transfer pump (FTP) is the only serviceable componentFTP field service kit available• Service instructions included with
kit
The fuel transfer pump is the only serviceable component. A field service kit is available and must be used to prevent damage to the HEUI pump when replacing the fuel transfer pump. A special bolt replaces the upper L.H. bolt (as viewed from FTP end of pump) to hold the HEUI pump together as the fuel transfer pump is removed.
Also be aware that there are special fasteners used here. The fasteners accept:Torx Plus T40 (OTC 6187 bit, or 6180 set)Torx Plus T27 (OTC 6185 bit)
Class Intro.ppt 23
ADEM 4 Electronic Engine Control
19878-bit
PEEC II
1991Advanced
8-bitPEEC III
1993Two 8-bitADEM II
1998 32-bitADEM III
2004 32-bitADEM 4
Generations of Experience
Proven Reliability
The ADEM4 (A4) control unit is a more powerful, faster electronic control unit
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ADEM 4 • Processing speeds and
memory increased• New 120 Pin engine
connector • Retains 70 Pin OEM
connector• More fuel maps to optimize
ACERT technology • Better performance• Better efficiency
Just like a home computer, the A4 ECM packs more processing power into the same ECM footprint. One of the easiest ways to recognize an A4 control unit is to look for the 120 pin engine connector. This is in contrast to the previous 70 pin engine side connector. The greater processing power allows for more complex and varied fuel maps to optimize ACERT technology.
Class Intro.ppt 25
ADEM 4• No change in OEM / machine
interface• Uses Cat ET• Common electronics from C6.6
to C32• Allows greater protection and
prognostics• Full machine integration
(Canbus, J1939, etc.)
The ADEM4 ECM is used throughout the C6.6 to C32 engine range. CAT ET interfaces just as it previously did with the ADEM3 ECM.
Class Intro.ppt 26
New ADEM 4 FeaturesThrottle input strategy• Multi-throttle capability• Configures throttle input priority
Engine control system options• Full range governor• Min max governor
Speed droop control• Simulates mechanical fuel system
performance• Adjustable from 0-10% droop
The ADEM4 give increased flexibility in strategies and options.
Class Intro.ppt 27
ADEM 4 CAN J1939 Data LinkHigh speed 2-way communications• Standard SAE link for all C-series engines• Broadcasts engine performance, status and
diagnostic information• Supports messages for powertrain
integration• Interfaces with Cat Messenger and analog
gauges
The A4 ECM utilizes the SAE J1939 high speed data link.
Class Intro.ppt 28
Turbocharger
• Provides higher boost over wide range
• Improves engine response
• Outstanding low end performance
• Improved peak torque
Single wastegate turbocharger
The single turbocharger now incorporates Wastegated boost control. The wastegate enables higher boost for better performance without the danger of over-boosting. Boost ratings vary by HP rating and are generally between 170 KPa (24 psi) and 193 KPa (27 psi).
Class Intro.ppt 29
Turbocharger Wastegate Function
BoostElevated BMEP
Improved Response
RPM
If boost is increased, there is a danger of too much cylinder pressure as rated speed and load is approached. Cylinder pressure is known as BMEP for Brake Mean Effective Pressure. BMEP is defined as the average pressure in the cylinder during the course of the combustion cycle. BMEP that is too high can have a detrimental effect on component life.
Class Intro.ppt 30
Turbocharger Wastegate Function
Wastegate Boost
Boost
Wastegate Active – Reduced BMEP
RPM
With a Wastegated turbocharger, boost pressure is reduced or “blown off” at higher RPM’s to keep cylinder pressure within safe limits. With a Wastegated turbo, the benefits of increase boost at lower RPM’s are achieved while the engine is protected from over-boosting at higher RPM.
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Cylinder Head4 valve, Crossflow design• Design to improve engine
breath-ability Robust 6 bolt design
cylinder head-block• Improved combustion
gas sealing• Minimize bore / liner
distortion
The cylinder head is a cross flow design that utilizes 4 valves per cylinder for improved breathing.
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Head bolt torque sequence1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27 2829 3031
The head bolt torque sequence shown in this slide needs to be followed when reinstalling the cylinder head.
Class Intro.ppt 33
Head bolt torque procedure
1. Tighten Bolts 1-26 in sequence to 130 +/- 15 Nm
2. Retighten bolts 1-26 in sequence to 130 +/- 15 Nm
3. Turn bolts 1-26 in sequence to an angle of 90 degrees
4. Loosen bolts 1-26 to a torque of 0 Nm
5. Repeat steps 1-3
6. Tighten bolts 27-31 to a torque of 28 +/- 7 Nm
Torque sequence includes tightening bolts 1-26, rechecking the tightening torque and then turning bolts 1-26 an additional 90 degrees.
Class Intro.ppt 34
Valve Lash AdjustmentSet number 1 cylinder to TDC compression
Adjust number 1,2, and 4 intake valves*
Adjust number 1,3, and 5 exhaust valves**
Turn crankshaft 360 deg.
Adjust number 3,5, and 6 intake valves*
Adjust number 2,4, and 6 exhaust valves**
Tighten adjusting screw locknut to 30 +/- 7 Nm
* 0.38 mm +/- .08 for intake valves
** 0.64 mm +/- .08 for exhaust valves
Valve lash adjustment is no different than before. After setting the engine at TDC compression on cylinder #1, it takes only one 360 degree revolution to adjust all the valves. Be certain to check the service manual for the latest valve clearance specifications
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Valve Cover
•Composite cover• Fully isolated base•Up to 1 dBA sound power reduction
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Valve and Seat Changes
• Increased valve size• Improved engine
breathing• Allows for higher
ratings• Higher burn
efficiency
Increased valve size in the four valve head aids in engine breathing.
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Intake Port Detail
Improved geometry• Smooth transitions• Less flow restrictions
Better intake port geometry has improved airflow in the C9 cylinder head compared to the C-9.
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Valve and Seat Changes
Reduced stem diameterReduced recessionImproved breathingKeeps clean
No carbon load-upImproved life
Class Intro.ppt 39
Mechanical Packaging
New lighter and stiffer rocker arms
New lighter and stiffer rocker bridge
Better response More reliable
Class Intro.ppt 40
Valve Spring Packaging
• New retainer• Taller / reduced
diameter springs• New spring seat
and stem seal• Robust reliable
design
Class Intro.ppt 41
Cylinder Block• Improved block and head
material strength • Strengthened flywheel
housing joint reduces leaks
• Sculpted design reduces noise
• Integral oil cooler reduces width, weight and potential leaks
With the increased cylinder pressures used in the C9 machine ACERT engine, the block material has been changed to increase block strength. Sealing has been improved throughout the engine.
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Cylinder Block
Mid-supported liner• Fewer sealing joints
for reduced risk of leaks
Integral oil cooler• Reduced weight,
leaks and engine width
Improved coolant & oil flow
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PistonsArticulated two piece design• Proven technology• Steel crown stronger than aluminum• Allows more flexibility in ring position• Excellent wear characteristics
The C9 machine ACERT engine utilizes a steel crown articulated piston.
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Hardened Plateau Honed Liner
Two step honing process:•Cuts deep grooves for oil
retention•Smoothes the tops off for
better wear surface and oil retention
•Improves oil control and consumption
Plateau honed liner improves oil control. Special honing techniques must be followed with these liners.
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Liners
Mid-support wet liner• Removable for
service• Fewer leak joints• Improved cooling in
combustion area• Allows advantages
of higher ring position
Mid support allows better cooling at the top of the cylinder so the rings may be located higher on the piston. Less dead volume above the rings helps with emissions.
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Connecting Rod
Heavy duty designForged steel •Increased strength
Fractured-split design•Perfect joint alignment
The fracture split connecting rods ensure perfect alignment of the rod cap. These connecting rods are CANNOT be rebuilt.
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Connecting Rod Notes
Lubricate rod bolt seating faces on the cap with clean engine oil or anti-seize
Orient the cap so that bearing tabs line up across the joint face.
Tighten each bolt to 50 +/- 5 Nm
Tighten each bolt an additional 90 +/- 5 deg.
Ensure that the parting faces of the connecting rod cap are clean and dry. The connecting rod bolt must be lubricated. After an initial torque of 50 Nm, each connecting rod bolt gets turned an additional 90 degrees.
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Crankshaft
Forged steel • Increased strength
and durability• Induction hardened
journal and fillets
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Camshaft• Carburized, heat-treated steel for
durability• High position allows use of short
pushrods for improved over-speed capability
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Leak Free Design
Improved joints through out the engine• Oil pan seal• Timing cover• Block to flywheel housing
All fluid connections sealed with standard thread “O” ring design
Heavy duty truck technology has been applied to the C9 to improve sealing throughout the engine.
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Specifications
149 mm (5.9 in)Stroke
112 mm (4.4 in)Bore
8.8 L (537 cu. In)Displacement
1800-2200Rated RPM
C9Model
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Specifications
1198 mm (47.2 in.)Length
819 mm (32.2 in.)Width
776 kg (1707 lbs.)Weight
1002 mm (39.5 in)Height
C9Model
Class Intro.ppt 53
Maintenance Information
500 hr. oil change intervalEquipped with new Cat’s high efficiency
oil filtersRefill capacities
Lube oil system (refill) – 28L / 7.4 galOther serviceability issues unchanged
Oil change interval has been standardized at 500 hours. S.O.S oil sampling is recommended to ensure confirmation of oil cleanliness. Oil should meet CAT ECF-1 specifications. (CH or CI rated oil with a maximum of 1.5% ash meets these specifications)
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High Efficiency Oil Filters
Revolutionary filter design• Increased contamination
control• Double the efficiency without
increasing the changing interval
• Reduces wear on all oil lubricated surfaces
Class Intro.ppt 55
Standard Equipment
HEP fuel pumpCrossflow cylinder headStrengthened blockIsolated valve coversCast iron front coverADEM 4 ECMWastegated turboArticulated pistons
Class Intro.ppt 56
Additional FeaturesFuel filter / water separatorSingle / dual rear PTOSerpentine drive beltCompression brakeCat MessengerJ1939 gauges
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