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SERT4072 May 2004

SERVICE TRAINING TECHNICAL PRESENTATION

ACERT™ TECHNOLOGY FOR C7 AND C9 ON-HIGHWAY ENGINES INTRODUCTION TO MECHANICAL CHANGES

ACERT TECHNOLOGY FOR C7 AND C9 ON-HIGHWAY ENGINES INTRODUCTION TO MECHANICAL CHANGES AUDIENCE Level II–Service personnel who understand the principles of machine systems operation, diagnostic equipment, and procedures for testing and adjusting.

CONTENT This presentation provides update information on the C7 and C9 ACERT On-highway Truck Engines. This presentation may be used for self-paced and self-directed training.

OBJECTIVES After learning the information in this presentation, the serviceman will be able to: 1. locate and identify the new mechanical components on the C7 and C9 ACERT Truck Engines, 2. explain the operation of the new components in the systems; and 3. explain new procedures in testing and adjusting.

PREREQUISITES 3126B CD Cat HI300 Fuel System C-9 CD Cat HI300B Fuel System C-9 Engine - Systems and Controls

RENR1390-01 RENR1392 SERH4050

Prior training in systems operation and testing and adjusting procedures for electronic engines should be completed before participating in this training session. Additionally, the participants should have PC skills including training in the current Windows™ operating system and the most current Caterpillar Service Technician Workbench/Electronic Technician (STW/ET) software.

REFERENCES C7 and C9 On-highway Engines - Troubleshooting Guide Pure Power Caterpillar On-Highway Engines with ACERT Technology TM

Estimated Time: 1 Hour Illustrations: 40 Form: SERT4072 Date: 5/04 © 2004 Caterpillar Inc.

SENR9517 LECT3965

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TABLE OF CONTENTS INTRODUCTION .......................................................................................................................5 C7 Engine Specifications .....................................................................................................11 C7 Iron Changes ..................................................................................................................12 C9 Engine Specifications .....................................................................................................17 C9 Iron Changes ...................................................................................................................18 FUEL SYSTEM .........................................................................................................................25 HEUI Pump .........................................................................................................................26 EXHAUST AFTERTREATMENT ............................................................................................31 Caterpillar Diesel Oxidation Catalyst (DOC) .....................................................................39 SUPPORT ..................................................................................................................................44 CONCLUSION ..........................................................................................................................45

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© 2004 Caterpillar Inc.

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INTRODUCTION This presentation covers the New Product Introduction (NPI) for the C7 and C9 on-highway engines using ACERT technology. The mechanical aspects of the engine are covered. The electronic changes are covered in a separate presentation: C7 and C9 ACERT Electronics, On-Highway Truck Engines (Form SERQ4049).

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This presentation will briefly describe ACERT technology. Also changes to the iron for the C7 and C9 engines will be described and what is different with the electronic control system on these engines.

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ACERT stands for Advanced Combustion Emissions Reduction 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.

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To identify the engines that use ACERT technology, there is a change to the model nomenclature. The model number is written with no hyphen. The C7 uses ACERT technology, but is based upon the familiar 3126E. The 3126B on-highway engine was renamed to the 3126E in 2001 to recognize the product enhancements that had been made. These included chrome ceramic structure rings, tungsten coated HEUI injectors, and new CFFV/LEV (Clean Fuel Fleet Vehicle/Low Emission Vehicle) ratings, and more. The C7 engine is the next progression for this 7 liter engine. Like the C7, the C9 is an in-line, 6 cylinder HEUI engine, turbocharged and air to air aftercooled. The C9 on-highway engine with ACERT technology is an updated version of the C-9 industrial/machine engine originally released for the 2000 model year. NOTE: Heavy duty engines with ACERT technology are covered in separate Service Training presentations, "ACERT Technology for C11 and C15 Heavy Duty Engines Introduction to Mechanical Changes" (Form SERT4052) and "Introduction to Electronic ACERT Technology for On-Highway Engines" (Form SERT4053).

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The C7 and C9 are similar in appearance, but the commonality goes beyond that.

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Both engines use an updated HEUI injector, a new hydraulic pump, a 48 tooth timing strategy, common sensors, an updated ADEM III ECM, and a diesel oxidation catalyst aftertreatment device. Each of these items is covered later in the presentation.

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C7 Engine Specifications The C7 specifications are the same as for the previous 3126E. Planned ratings for the C7 will range from 141 kW (190 horsepower) with 705 Nm (520 lb. ft.) torque, to 246 kW (330 horsepower) with (1,166 Nm) 860 lb. ft. torque for fire truck, RV, emergency, and roadside recovery rating.

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C7 Iron Changes There is approximately 13% new content when comparing the C7 to the 3126E.

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In ratings of 171 kW (230 horsepower) and above, the C7 uses a monosteel piston. The 3126B will continue to use the present steel articulated pistons. In the 141 and 156 kW (190 and 210 horsepower) ratings, the C7 ACERT uses one-piece aluminum pistons that are similar in appearance to those used in the 3126B in the lower horsepower ratings. However, the C7 has a different combustion crater design. The 3126B piston would interfere with the new injector tip in the C7, if the wrong piston were used.

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The C7 cylinder head was modified to accept the new injectors. Also, the bolt pattern was changed to accommodate the new valve cover base. The base is fully isolated with ribbon seal and isolator bolts. Because the C7 has a higher peak cylinder pressure than the 3126E, the C7 requires a stronger iron chemistry for the block.

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The C7 uses a new, composite valve cover. The valve cover is semi-isolated, with ribbon seal and shoulder bolts.

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There is a side cover mounted breather which uses a rubber coated steel gasket for sealing.

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C9 Engine Specifications The C9 basic specifications are the same as the C-9 industrial engine. Planned ratings for the C9 will range from 205 kW (275 horsepower) with 1166 Nm (860 lb. ft. torque), to 298 kW (400 horsepower) with 1491 Nm (1100 lb. ft. torque) for the RV (D tier) rating.

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C9 Iron Changes The C9 is a medium duty engine with heavy duty characteristics. With no spacer deck, there are fewer sealing joints, thus reducing the possibility of leaks. The integral oil cooler cast in the block reduces weight and width of the engine and also eliminates external lines. High coolant and oil flow provides long engine life.

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For the C9 engine with ACERT technology, the block uses iron chemistry to allow higher cylinder pressure capability. Tensile strength of the block is 220 mPa (32,000 psi) which is the same as the 3176C and 3196 industrial engine blocks. The flywheel housing joint has been strengthened for longer life. The housing joint is the same as used on the 3176C and 3196 industrial engines. The cylinder block is a single piece, deep skirted, serpentine design, shaped to increase stiffness and reduce weight and noise.

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The C9 has mid-supported wet liners for increased life and excellent rebuildability. The mid-support feature allows a higher top ring position, which improves fuel consumption and emissions. The high strength, grey cast iron liner has an induction hardened internal surface to provide extended wear life. Plateau honing provides excellent oil control.

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The C9 cylinder head is a 4 valve, cross flow design for excellent breathing capability which results in better fuel consumption and emissions. A robustly designed cylinder head casting provides long life. A six bolt per cylinder design provides better sealing and minimizes bore/liner distortion.

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The crankshaft is a single piece steel forging with induction hardened journals and fillets. The crankshaft is regrindable.

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Like the C7, the C9 uses a steel forged, fractured connecting rod. The design allows the rod to be removed through top of cylinder for ease of service. The fractured surfaces of the rod and cap should be handled carefully to prevent damage when servicing. This rod is not rebuildable in the event of a spun bearing. Replacement is the only option after a bearing failure which has caused damage to the bearing bore. Normal reusability guidelines should be followed. If the rod is not reusable, it is scrapped. This rod is a relatively low cost item. For this reason, oversize bearings are not supplied and therefore rebuilding is not an option.

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The camshaft is carburized and heat treated, and is supported in the block by four aluminum bearings. The high position of the camshaft allows for the use of shorter push rods for improved durability and overspeed capability. The C7 and C9 engines both use the same cam gear. As mentioned earlier, the engines use a 48 tooth timing strategy. Actually, the strategy is referred to as a "48 minus 1" tooth arrangement. The speed/timing sensors read the spaces between the teeth. With a 48 tooth pattern, one tooth is absent, to identify the TDC (Top Dead Center) position.

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FUEL SYSTEM Both the C7 and the C9 use the latest HEUI-B Fuel System. Like all HEUI engines, the fuel system provides excellent performance since the injection pressure is nearly independent of engine speed. The HEUI-B system has enhanced, electronically controlled, injection rate shaping capability. The proprietary design of this system allows infinite fuel delivery strategies. Depending on engine operating speed and load, the system uses a variety of shaped injection traces. This capability results in reduced emissions at the point of combustion, while preserving engine reliability and durability

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HEUI Pump The C7 and 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 ccs volumetric output per revolution versus the earlier pump's capability of 8 ccs per revolution. The C7/C9 pump has 28 mPa (4,060 psi) relief valve pressure vs. 26 mPa (3,770 psi) for the earlier pump. The pump 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.

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The C7 and C9 pumps operate at different drive speeds. This is accomplished by using different front drive gears. The C7 has a 36 tooth gear, providing a 1.38:1 ratio. The C9 has a 31 tooth gear, giving it a 1.61:1 drive ratio. The C9 needs more oil flow, so the pump turns at a faster rpm on the C9 engine. Also, the C9 has an iron mounting flange for increased strength, while the C7 uses an aluminum mounting flange like on the 3126E. In summary, although the actual pumps are identical, the gears and the mounting flanges are different.

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24 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 (Brake Specific Fuel Consumption) improvement on the engine as compared to the fixed volume per revolution pump used on the 3126B. This pump uses a port-metering principle to regulate the volume of pressurized actuation oil. This principle 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. Caterpillar has 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°C (230°F). Manufactured oil, simulating old contaminated engine oil, was used for durability testing.

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25 This illustration shows port metering in the low flow position which provides low oil flow to the injectors, resulting in a reduction of injection pressure.

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26 Here is the port-metering in the high flow position which will provide high oil flow to the injectors, resulting in an increase of injection pressure.

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27 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 position 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 position is referred to as the "Zero effective stroke."

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28 This illustration shows the oil flow through the pump from minimum flow to maximum flow. The movie clip demonstrates the following points: - Port metering - Control solenoid - Control actuation - Fixed swash plate (Click on the image in the Power Point presentation to start and stop the movie clip.) NOTE: This illustration is animated on the C-9 CD RENR1392.

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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 special fasteners are used. The fasteners accept: - Torx Plus T40 (OTC 6187 bit, or 6180 set) - Torx Plus T27 (OTC 6185 bit)

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There is a diagnostic test for the pump in the appropriate engine Troubleshooting Guide. Follow this guide: - if the engine will not start - if actual hydraulic pressure is not tracking desired pressure - if the pump is suspect

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AFTERTREATMENT A simple effective exhaust aftertreatment completes the story of ACERT technology: the Caterpillar Diesel Catalyst (DOC). The DOC converts harmful by-products of the combustion process into harmless substances that are passed on out of the exhaust system. The aftertreatment device will usually look like a normal muffler. The difference is within the casing.

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The exhaust gas first enters the element through a diffuser can. This spreads out the gases to use the entire converter instead of just a single spot. After passing through the converter, the gas enters the muffling element.

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If desired by an OEM, the vehicle could have a independent catalytic converter and a separate muffler, much like the arrangement on a car. An independent catalytic converter (ICC) is separate from the muffler. An ICC requires the truck OEM to engineer where the ICC will fit in the exhaust system. The ICC requires heat shields around it in order to protect the rest of the truck and any service personnel from the high operating temperatures.

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The catalytic element is a porous ceramic substrate with a precious metal catalyst coating. Flow passes through the honeycomb design channels. The cross sections here show the ceramic substrate (yellow) which is "wash coated" (white) with an aluminum oxide catalyst. As exhaust gases flow past the coating, a reaction occurs that changes the chemical compounds in the exhaust gases.

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Caterpillar Diesel Oxidation Catalyst (DOC) This diagram represents a single channel in the converter. The diagram shows the ceramic substrate, wash coat, small particles of platinum in the wash coat, and the compounds in the exhaust gas coming into and exiting the converter. Typically strategies to reduce NOx cause an increase in hydrocarbons. The purpose of the DOC is to clean up the hydrocarbons. Emissions from the engine include: hydrocarbons (HC), carbon monoxide (CO), NOx, particulate matter (PM, consisting of soot + SOF + sulfates), oxygen (O2). SOF, which stands for Soluble Organic Fraction, is basically unburned fuel and oil. As the exhaust flows through the channels of the substrate, the reaction within the catalyst changes the hydrocarbons and carbon monoxide to carbon dioxide and water. NOx is not affected by the converter. However, due to ACERT Technology, the NOx is reduced at the point of combustion. Chemicals from the engines exhaust that enter the converter: HC = Hydrocarbon CO = Carbon Monoxide NOx = Nitrogen Oxide or Oxides of Nitrogen PM = Particular Matter (soot+SOF+sulfates) O2 = Oxygen

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Chemicals that exit the converter: CO2 = Carbon Dioxide H2O = Water NOx = Nitrogen Oxide or Oxides of Nitrogen PM = Particular Matter (soot+sulfates) O2 = Oxygen Catalyst: Al2O3 = Aluminum Oxide

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The Caterpillar Diesel Oxidation Catalyst (DOC) is similar to, yet different from, the catalytic converters used on automobiles. The Diesel Oxidation Catalyst is designed to run cooler, work with leaner exhaust, and have different catalytic reactions. The Diesel Oxidation Catalyst is precious metal based, using platinum.

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37 This technology has been in production at Caterpillar since 1994, originally on the 3116 truck engines. Current development optimizes size, precious metal loading, and other features. Caterpillar developed a "low cost" Oxidation catalyst in 2000 - 2001 for use on the 3126B/E low emissions vehicle applications. Heavy duty on-highway engines also began using aftertreatment effective with the October, 2002 build. This continues with the heavy duty on-highway engines using ACERT technology.

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Raw fuel or oil in the DOC will cause problems: - increased back pressure - increased exhaust temperature - deteriorated catalytic action Running the vehicle on a chassis dynamometer will usually clean out a converter contaminated with fuel or oil. Engines equipped with catalytic converters will have higher nominal back pressure. Check the Systems Operation Testing and Adjust Manual (SOTA) for maximum levels.

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SUPPORT For support, technicians are available at the Caterpillar On-Highway Engine Call Center 24 hours a day, seven days a week to answer your technical questions. Upon calling the 800 number shown on the illustration, a voice menu will direct the caller to the appropriate contact to handle your situation. The e-mail address for the call center is shown above. Contacts: The phone number shown above should be used for technical assistance with the C7 and C9 engines.

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CONCLUSION ACERT stands for: A

Advanced

C

Combustion

E

Emission

R

Reduction

T

Technology

ACERT technology takes Caterpillar to the next generation of diesel engines without the necessity of EGR and other maintenance intensive accessories. In brief, ACERT technology could be termed as sophisticated simplicity. The problems of meeting the emissions standards are met with sophisticated, intelligent software, and cutting edge injectors using the latest technology. This technology does not result in additional sophistication in maintenance and repair.