Usage:
3612 (9RC),
3616 (1PD) Engines
Reference: Special Instruction, REHS0255, "Field Replacement Of The Standard Aftercooler With The High Performance Aftercooler".
Reference: Engine Data Sheet 50.5, LEKQ7235, "Cooling System Field Test".
Description of Change: New High Performance Aftercooler (HPAC) parts kits are available for these engines. The HPAC provides greater effectiveness in reducing air inlet temperatures, as compared to the standard aftercooler. An added benefit of the HPAC is reduced exhaust gas temperature, resulting in increased exhaust valve life. The parts kits include all the necessary parts to retrofit the HPAC to engines that are currently equipped with the standard aftercooler.
Retrofitting with the HPAC will provide the greatest benefit to the user who experiences high exhaust temperatures at full load. The HPAC provides greater reduction in inlet air temperature, which in turn reduces exhaust gas temperatures. One of the benefits of reduced exhaust temperature is longer exhaust valve life. However, the additional heat transfer to the cooling system may overburden the cooling system, leading to overheating. Therefore, cooling system capacity may have to be increased when retrofitting an engine with the HPAC. Refer to the Reference (Engine Data Sheet 50.5, Form LEKQ7235), for additional information on requirements for the cooling system.
Additionally, the benefits of aftercooling (in reducing exhaust temperature) are diminished as engine load drops below full load. Therefore, engines experiencing cyclic loading will not see as great a reduction in exhaust temperatures. In engine applications that do not experience excessive exhaust temperatures, the benefits of the HPAC may not be sufficient to justify the additional expense of the retrofit.
Adaptable To: New production 3612 (9RC259-Up) and 3616 (1PD335-Up) Engines have the HPAC as standard equipment. The 175-7858 Parts Kit is available to retrofit the HPAC to earlier 3612 (9RC1-258) Engines that are currently equipped with the standard aftercooler. The 175-7857 Parts Kit is available for retrofit to earlier 3616 (1PD1-334) Engines that currently have the standard aftercooler. The Reference Special Instruction provides complete information for replacing a standard aftercooler with a HPAC.
NOTE: The 175-7857 Parts Kit and 175-7858 Parts Kit are "Made As Ordered" and may require UP TO SIX (6) MONTHS DELIVERY TIME AFTER ORDERING. It is imperative that orders for these parts kits are placed well in advance.
NOTE: The 175-7857 Parts Kit and the 175-7858 Parts Kit are NON-RETURNABLE. Once an order for the 175-7857 Parts Kit or the 175-7858 Parts Kit has been placed, the order CANNOT be canceled.