COMPRESSOR GP-REFRIGERANT 3794415 - Caterpillar

The affects of ambient air temperature changes must be held to a minimum. The separate circuit aftercooler water must be held to 32 4° (90 7°) or 54 4° (130 7°) to ensure that the air fuel ratio does not change. A temperature control valve must be installed in the aftercooler water circuit to regulate water flow. The schematic that follows illustrates how the thermostatically controlled valve should be installed.
(1) Radiator for aftercooler water. (2) AMOT valve. (3) Auxiliary water pump. (4) Aftercooler inlet. (5) Aftercooler outlet. (A) AMOT valve outlet. (B) AMOT valve bypass inlet. (C) AMOT valve normal inlet.The altitude at which an engine is installed will affect performance. When the installation of the engine is over 152 m (500 ft.) above sea level one spacer should be removed from the pressure differential valve (wastegate) to maintain the correct horsepower rating. Refer to the instructions that follow before removing a spacer from the pressure differential valve.
The pressure regulator cover is heavily spring loaded. To avoid personal injury do not deviate from the following procedure.
1. Remove the regulator from the engine.2. Modify three 1B2716 (1/4-20 NC x 5 in.) bolts, by running a 1/4-20 NC die nut the full length of the bolts.3. Remove three retaining bolts, one at a time, and replace each with a modified bolt to keep the cover contact surface parallel with the regulator body surface. Tighten the modified bolts enough to relieve pressure on the other two retaining bolts. Remove the two retaining bolts. Loosen the modified bolts alternately to relieve the spring tension.4. Remove one spacer from between the valve body and cover.5. Assemble the cover to the regulator body by using the modified bolts until the retaining bolts can be installed. Tighten the bolts to a torque of 6.3 1.7 N m (55 15 lb ft).Refer to the charts that follows to determine the altitude capabilities of the engines with one spacer removed. One spacer was removed for operation at 152 m (500 ft.) or more above sea level. The combustion air flow for a low emission engine is considerably higher than the standard engine. Heat rejection values for the low emission engine are correspondingly higher and are shown in the following chart. The values listed are for standard conditions. As the ambient temperature and altitude increase, the heat rejection also increases. Use the appropriate multiplier from the graphs that follow to obtain the design heat rejection value. For example, a G398 low emission engine applied at the 32°C (90°F) aftercooler water rating has an aftercooler heat rejection of 5,000 Btu/min. If the job site is at 1219 m (4000 ft.) and the maximum ambient temperature expected is 38°C (100°F), the multiplier is approximately 1.34. The actual heat rejection at this altitude and ambient temperature would be 5000 x 1.34 = 6700 Btu/min. This value does not allow for any deterioration in cooling capacity of the heat exchanger used to cool the aftercooler