910103-5825 Tohatsu BOLT

References
This Special Instruction is to be used with the publications that are listed below. Consult these publications for additional information.
Marine Engine Application and Installation Guide, LEKM9213
Marine Engine Sea Trial Guide, LEBM5081
3500 Marine Engine Performance Handbook, LEBM9090
3500B Engine Application And Installation Guide, LEBM7301
Operation and Maintenance Manuals - 3500B Marine Propulsion Engines and 3500 Marine Propulsion Engines with EUI, SEBU6917
Operation and Maintenance Manuals - 3508, 3512, and 3516 Marine Engines, SEBU6100
Linear Vibrations, LEKQ4023Exhaust Temperature Sensitivity Calculation
High exhaust temperature in an engine is a major contributor to the reduced life of a component. The life of turbochargers and valves is greatly affected by continued exposure to high exhaust temperatures to the inlet of the turbocharger. Refer to the Technical Marketing Information (TMI). This exhaust temperature sensitivity calculation is applicable to all 3500 Marine Propulsion Engines.There are several variables in every installation that may have a significant impact on exhaust temperature. The exhaust temperature sensitivity calculation ensures that the design of the system takes all the different variables into consideration prior to installation.Use the worksheets for the exhaust temperature sensitivity calculation in order to size the exhaust piping for the 3500 Engines and the 3500B Engines. This worksheet will help determine the critical factors that must be considered when an installation is planned. The completed calculation will result in the expected temperature to the inlet of the turbocharger. Use the following information in order to perform the calculation: the expected maximum altitude, the ambient temperature, the restriction to the air inlet and the exhaust and the aftercooler temperature for the engine.If the calculated temperature is below the maximum temperature to the inlet of the turbocharger, the normal life of the engine may be expected. Refer to the ""TMI Exhaust Turbine Inlet Maximum Temperatures"" section. If the temperature is above the maximum temperature to the inlet of the turbocharger, changes in the installation must be made in order to reduce the maximum expected exhaust temperature. If changes are not made, the life of the component may be affected.TMI Exhaust Turbine Inlet Maximum Temperatures
Table 1
Maximum Exhaust Turbine Inlet Temperatures    
    Normal Operating Temperature (maximum)     Extreme Condition Temperature (maximum)    
Marine Dry Manifold    
A     650 °C (1200 °F)    
692 °C (1275 °F)    
B and C (1)    
677 °C (1250 °F)    
718 °C (1325 °F)    
D and E (1)    
704 °C (1300 °F)    
746 °C (1375 °F)    
Marine Wet Manifold    
A    
566 °C (1050 °F)    
607 °C (1125 °F)    
B    
579 °C (1075 °F)    
621 °C (1150 °F)    
C    
593 °C (1100 °F)    
635 °C (1175 °F)    
D    
635 °C (1175 °F)    
677 °C (1250 °F)    
E    
677 °C (1250 °F)    
718 °C (1325 °F)    
( 1 ) Including High Performance Ratings.Exhaust Turbine Inlet Temperature Sensitivity Worksheet (Metric Units)
Table 2
(A)    (B)    (C)    (D)    (E)    (F)    
Site Data TMI Standard    B - C    Sensitivity    D x E    
Air Filter inlet temperature         25 °C         1.8 °C increase per 1.0 °C (D)        
Aftercooler water temperature         TMI         1.25 °C increase per 1.0 °C (D)        
Air inlet restriction         4 kPa         6.8 °C increase per 1 kPa (D)        
Exhaust restriction         0 kPa         4.0 °C increase per 1 kPa (D)        
Altitude         0 meters         3.6 °C increase per 100 meters (D)        
    Total Column F        Air Filter Inlet Temperature
Take the temperature at the air filters when the engine is operating at the rated load. Record this temperature in column "B".
Subtract the value in column "C" from the value in column "B". Record the answer in column "D".
Multiply the value in column "D" times 1.8 and record the answer in column "F".Aftercooler Water Temperature
Take the temperature of the aftercooler water when the engine is operating at rated load. Record this value in column "B".
Record the temperature of the TMI aftercooler water in column "C". For example, the following information is indicative of standard parameters: the temperature is 90 °C for jacket water aftercooled 3500 mechanical unit injection (MUI) Engines, the temperature is 30 °C for 3500 MUI Engines that use separate circuit aftercooling and 3500 electronic unit injection (EUI) Engines may have a temperature of 30 °C, 60 °C, or 90 °C.
Subtract the value in column "C" from the value in column "B". Record the answer in column "D".
Multiply the value in column "D" times 1.25 and record the answer in column "F".