Centinel System – Repair Manual – 014-005   Engine Testing (Engine Dynamometer)

NOTE: Due to the number of engines and applications, this procedure has been written to be generic. Illustrations within this procedure will not represent all engines and applications.

NOTE: Make sure the dynamometer capacity is sufficient to permit testing at 100 percent of the engine’s rated horsepower. If the capacity is not enough, the testing procedure must be modified to the restrictions of the dynamometer.

Use engine lifting fixture, Part Number 3162871, to install the engine test stand. Align and connect the dynamometer. Refer to the manufacturer’s instructions for aligning and testing the engine.

Connect the coolant supply to the water inlet connection.

Connect the coolant return to the water outlet connection.

Install the drain plugs and close all of the water drain cocks.

The use of a remote aftercooler is mandatory whenever a Cummins® charge-air cooled engine is attached to an engine dynamometer for the purpose of engine run-in, performance testing, and/or engine diagnostics. Do not attempt to run a Cummins® charge-air cooled engine without a means of controlling the intake manifold air temperature. Dynamometer-room charge-air cooler, Part Number 3823978, utilizes twin Big Cam™ III aftercooler assemblies arranged for parallel air and water flow to cool the intake air to acceptable levels.

The parallel airflow circuit heat exchangers provide optimum performance by delivering air to the mixer at temperatures no higher than 66°C [151°F] and with less than the maximum allowable intake air pressure drop. The remote aftercooler removes energy from the intake air compressed and heated by the turbocharger to temperatures as high as 210°C [410°F] and then cooled to temperatures of 66°C [151°F] using city water at 16°C [61°F].

1. Water in
2. Aftercooler number 1 (2 pass)
3. Aftercooler number 2 (2 pass)
4. Water out
5. Condensate
6. From turbocharger
7. To intake manifold
8. Thermocouple (Fluke™).

Water from a city tap line flows to the aftercooler through a 25.4 mm [1-inch] inner diameter neoprene hose. Testing has shown that 45.4 liter [12 gal] per minute city water flow is required (22.7 liter [6 gal] per minute per aftercooler core) to adequately cool the intake air for the 435 through 500 horsepower-rated engines. A typical garden hose is not suitable for this flow, due to the excessive restriction. A low-restriction ball-type or gate valve is suitable for the operation, provided that the required flow rates are achieved.

Water returns to the drain or reservoir from the aftercoolers through a 25.4 mm [1-inch] inner diameter hose. A low-restriction gate valve or ball valve must be placed on the drain line(s) to regulate water flow through the aftercoolers. This provides the ability to maintain optimum intake air temperature during the test or run-in procedure.

The condensate that will develop as the intake air is cooled in the remote aftercooler is allowed to drain at all times through a hole at the bottom of the tubular steel manifold between the aftercoolers. This fitting must remain unobstructed throughout each use of the aftercoolers.

NOTE: Some air will escape through the condensate drain opening, but it is insignificant compared to the total airflow.

1. Air in from turbocharger compressor outlet
2. Lifting eye
3. Air out to engine intake manifold
4. Water in to aftercooler
5. Water out to drain
6. Condensate drain.

The airflow piping requires a 101.6 mm [4 in] inner diameter aluminum steel piping. The flow circuit must have as few bends as possible, maximizing the length of straight sections. However, when bends are required, use long elbows. Do not use square elbows or anything that changes the airflow direction quickly. To reduce intake air restriction, airflow direction changes must occur gradually.

NOTE: All air compressors manufactured by Cummins Inc. must operate during the engine run-in. During the performance check, all air compressors must be in the unloaded or non-operating mode.

Connect a source of compressed air capable of producing 665 kPa [96 psi] to the air compressor unloader (1). This air line must contain a valve between the air source and the unloader.

NOTE: The compressed air load in the accompanying illustration must be attached to the air compressor outlet (2).

Use an air tank (2). Install an air regulator (3) capable of maintaining 345 to 517 kPa [50 to 75 psi] of air pressure at both minimum and maximum engine rpm.

Install a steel tube or high temperature hose (1).

Hose Temperature

Connect the tube or hose (1) to the air compressor outlet.

Inspect the voltage rating on the starting motor before installing the electrical wiring.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

Install the electrical wiring to the starting motor and batteries, if used.

If another method of starting the engine is used, follow the manufacturer’s instructions to make the necessary connections.

Engines operating on an engine dynamometer require the engine harness be installed and connected to the engine. Additionally, the engine controller harness, Part Number 3164242, and engine controller, Part Number 3163890, must be used to properly control the engine during the dynamometer run.

Connect the engine controller harness Deutsch™ connector to the ECM OEM port.

Return parameters to their original value when the test or run-in is complete.

Connect battery power to the starter.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

Connect the dynamometer test OEM wiring harness starter solenoid lead (yellow) to the starter solenoid. Connect the ground lead (black) to the starter or battery negative (-) or ground side. Connect the +12-VDC power lead (red) to either the starter or battery positive (+12-VDC) side.

Connect the keyswitch panel data link cable to the Cummins® electronic service tool.

Use INSITE™ electronic service tool to set the engine up for the dynamometer. Refer to Procedure 014-008 in Section 14 for more information on this feature.

The setup is now complete, and the auto/manual throttle can be used to control engine speed.

To monitor engine performance correctly, record the following parameters. To limit dynamometer operating time, instrument the engine or use INSITE™ electronic service tool to make as many checks as possible.

• Engine speed (RPM)
• Fuel rate
• Intake manifold air temperature
• Engine blowby
• Engine coolant pressure
• Engine coolant temperature
• Rail fuel pressure. Use the following reference for ISM applications. Refer to Procedure 005-016 in Section 5. Use the following reference for ISX applications. Refer to Procedure 005-016 in Section 5.
• Engine fuel temperature (if needed to correct fuel rate)
• Fuel inlet restriction. Use the following reference for ISM applications. Refer to Procedure 006-020 in Section 6. Use the following reference for ISX applications. Refer to Procedure 006-020 in Section 6.
• Fuel drain line restriction. Use the following reference for ISM applications. Refer to Procedure 006-012 in Section 6. Use the following reference for ISX applications. Refer to Procedure 006-012 in Section 6.
• Intake manifold pressure. Use the following reference for ISM applications. Refer to Procedure 010-024 in Section 10. Use the following reference for ISX applications. Refer to Procedure 010-024 in Section 10.
• Intake air restriction. Use the following reference for ISM applications. Refer to Procedure 010-027 in Section 10. Use the following reference for ISX applications. Refer to Procedure 010-027 in Section 10.
• Exhaust restriction. Use the following reference for ISM applications. Refer to Procedure 011-009 in Section 11. Use the following reference for ISX applications. Refer to Procedure 011-009 in Section 11.
• Engine oil pressure. Use the following reference for ISM applications. Refer to Procedure 007-021 in Section 7. Use the following reference for ISX applications. Refer to Procedure 007-021 in Section 7.

Use INSITE™ electronic service tool to monitor engine speed.

Observe and record the engine speed.

See the Fuel Flow Measurement on Engine or Chassis Dynamometer in this section.

Adjust the fuel rate reading to compensate for temperature variation if required.

Fuel Inlet Temperature

When operating an engine on a chassis dynamometer, lock the cooling fan in the ON position for best results.

If the unit does not have a manual fan switch, use INSITE™ electronic service tool/Set Up for Dynamometer feature to lock the fan in the ON position. Refer to Procedure 014-008 in Section 14.

Use INSITE™ electronic service tool to monitor the intake manifold air temperature.

Observe and record the intake manifold air temperature.

The intake manifold air temperature must not exceed the maximum allowable temperature. See the Specifications – Engine Testing page in this section for the maximum allowable intake manifold air temperature. The engine protection system will disrupt performance if the temperature exceeds this level. Maintain the intake manifold air temperature below the maximum allowable temperature during chassis dynamometer operation.

If the intake manifold air temperature exceeds the maximum allowable temperature during the test, unload the dynamometer and allow the engine to cool.

Shut the engine off and inspect the charge air cooler fins for obstructions to the airflow.

Check the fan drive. Make sure the fan is locked in the ON position.

Remove any obstructions, such as a winterfront or debris. Manually lock the shutters in the OPEN position, if equipped.

Inspect the dynamometer room for an adequate supply of suitably cool or outside air. Make sure that dynamometer room air recirculation is not an issue.

Use blowby checking tool, Part Number 3822566 (ISM) or Part Number 3822567 (ISX), and water manometer, Part Number ST-1111-3, to measure the engine crankcase pressure.

Install the blowby checking tool to the end of the blowby tube. Install the water manometer to the blowby checking tool. Operate the engine at advertised horsepower rpm at full load. Observe and record the blowby.

Engine blowby must not exceed the maximum allowable specifications. Refer to Procedure 014-010 in Section 14.

Use pressure gauge, Part Number 3822995, to measure engine coolant pressure.

Observe and record engine coolant pressure.

See the Specifications – Engine Testing page in this section for the maximum allowable engine coolant pressure.

Use INSITE™ electronic service tool to monitor engine coolant temperature.

Observe and record the engine coolant temperature.

See the Specifications – Engine Testing page in this section for the maximum allowable coolant temperature.

If the coolant temperature exceeds the maximum allowable coolant temperature, unload the dynamometer and allow the engine to cool.

Shut the engine off and inspect the radiator fins for obstructions to the airflow.

Check the fan drive. Make sure the fan is locked in the ON position.

Remove any obstructions, such as a winterfront or debris. Manually lock the shutters in the OPEN position, if equipped.

Inspect the dynamometer room for an adequate supply of suitable cool or outside air. Make sure that dynamometer room air recirculation is not an issue.

Use immersion probe, Part Number 3824965, with a digital multimeter, Part Number 3377161, and a thermocouple module, Part Number 3824963, to monitor fuel temperature.

Observe and record the engine fuel temperature.