Usage:
Exhaust Temperature Sensitivity Calculation
High exhaust temperature in an engine is a major contributor to reduced engine component life. The life of turbochargers and valves are greatly affected by continued exposure to exhaust temperatures in excess of the maximum inlet to turbocharger temperatures, as published in the Technical Marketing Information (TMI). This exhaust temperature sensitivity calculation is applicable to all 3500 Series Engines.
There are several variables in every engine installation that can have a significant impact on engine exhaust temperature. The "Exhaust Temperature Sensitivity Calculation" ensures that the system design takes all the different variables into consideration prior to engine installation.
The "Exhaust Temperature Sensitivity Calculation Worksheets" on the following pages should be used as a guide by customers and dealers when sizing a system for 3500 and 3500B Engines. This worksheet will help determine the critical factors that must be considered at the time an engine installation is being planned. When the worksheet calculation is completed using the expected maximum altitude, ambient temperature, restriction (air inlet and exhaust), and aftercooler temperature for the engine, the result will be an "expected inlet to turbocharger temperature".
If the calculated temperature is below the maximum "inlet-to-turbocharger" temperature, as shown in TMI, and the charts in this publication, normal engine life can be expected. If the temperature is above the maximum "inlet-to-turbocharger" temperature, changes in the installation must be made to reduce the maximum expected exhaust temperature. If changes are not made, engine component life can be affected.
Do not perform any procedure, outlined in this publication, or order any parts until you have read and understood the information contained within this Special Instruction.
TMI Exhaust Maximum (measured at inlet to turbocharger)
Exhaust Temperature Sensitivity Worksheet Metric Units
Air Filter Inlet Temperature
1. Record, in column B, temperature at engine's air filters when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 1.8 times column D and record the answer in column F.
Aftercooler Water Temperature
1. Record, in column B, the engine's aftercooler water when operating at rated.
2. Record, in column C, the engine's TMI aftercooler water temperature. Example: 3500 MUI Engines are 90°C for JWAC and 30°C for SCAC, and 3500 EUI Engines may be 30°C, 60°C, or 90°C.
3. Subtract column C from column B and record the answer in column D.
4. Multiply 1.25 times column D and record the answer in column F.
Air Inlet Restriction
1. Record, in column B, engine's air filter restriction when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 6.8 times column D and record the answer in column F.
Exhaust Restriction
1. Record, in column B, engine's exhaust restriction when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 4.0 times column D and record the answer in column F.
Altitude
1. Record in column B, altitude of installation.
2. Subtract column C from column B and divide by 100, then record the answer in column D.
3. Multiply 3.6 times column D and record the answer in column F.
Total Column "F"
1. Degrees Centigrade that ambient site operating conditions affect the turbocharger inlet exhaust temperature.
2. Add "Total Column F" to engine's TMI "EXH MANF TEMP" and the answer is the expected turbocharger inlet exhaust temperature of the engine at rated, when operating at these ambient site conditions.
Exhaust Temperature Sensitivity Worksheet English Units
Air Filter Inlet Temperature
1. Record, in column B, temperature at engine's air filters when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 1.8 times column D and record the answer in column F.
Aftercooler Water Temperature
1. Record, in column B, the engine's aftercooler water when operating at rated.
2. Record, in column C, the engine's TMI aftercooler water temperature. Example: 3500 MUI Engines are 194°F for JWAC and 86°F for SCAC, and 3500 EUI Engines may be 86°F, 140°F, or 194°F.
3. Subtract column C from column B and record the answer in column D.
4. Multiply 1.25 times column D and record the answer in column F.
Air Inlet Restriction
1. Record, in column B, engine's air filter restriction when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 3.0 times column D and record the answer in column F.
Exhaust Restriction
1. Record, in column B, engines exhaust restriction when operating at rated.
2. Subtract column C from column B and record the answer in column D.
3. Multiply 1.8 times column D and record in column F.
Altitude
1. Record, in column B, altitude of installation.
2. Subtract column C from column B and divide by 1000, then record the answer in column D.
3. Multiply 20.0 times column D and record the answer in column F.
Total Column "F"
1. Degrees Fahrenheit that ambient site operating conditions affect the turbocharger inlet exhaust temperature.
2. Add "Total Column F" to engine's TMI "EXH MANF TEMP" and the answer is the expected turbocharger inlet exhaust temperature of engine at rated, when operating at these ambient site conditions.
3500 Engine Performance Parameters
Air System
Exhaust System
Oil System
Fuel System
Water System
Generator
3500 Generator Set Start-up Checklist
Engine Checklist
Generator Check List