TM 9-2815-225-34&P 3-92.  ENGINE DYNAMOMETER TESTING (Contd) LOCATION/ITEM ACTION REMARKS CAUTION Lubricating oil pressure should remain at or near a constant figure at constant engine speed and load after normal operating temperature is reached.  Acceptable lubricating oil pressures are 5-20 psi (34-138 kPa) at idle speed and 35-45 psi (241-310 kPa) for Big Cam  III  and  40-75  psi  (276-517  kPa)  for  Big  Cam  I  at  rated  speed.    Abnormally  high pressures may indicate blocked lubricating oil lines.  Abnormally low pressures indicate an insufficient supply of lubricating oil from the pump or increased engine clearances which may be due to bearing failure.  Damage to engine may occur if oil pressure falls outside of acceptable range at indicated speeds. Lubricating  oil  temperature  must  not  rise  sharply  above  225°F  (107°C).    Shut  down engine and correct as necessary.  Damage to engine may occur if oil temperature rises above acceptable limit. Check  temperature  of  coolant.    Temperature  should  not  exceed  200°F  (93°C)  or  drop below 160°F (71°C) during engine tests.  Do not turn engine off immediately after a load run.    Heat  stored  in  engine  will  boil  coolant  in  the  water  jackets  if  air  and  coolant circulation   are   immediately   stopped   while   engine   is   hot.      Allow   engine   to   idle   a minimum of three minutes before shutting down. Do not idle engine for prolonged periods of time before completing break-in running. b.  Break-in Running 4.   Engine (8) Start engine (8) and check oil Idle at approximately 1200 rpm pressure, oil temperature, and no-load for 5 to 10 minutes. water temperature.  Check for leaks. Operate air compressor (7) in pumping mode. 3-682