Technical data

13773-001
79-00
Page 1
OIL
1. GENERAL
This chapter covers those units and components external to the engine concerned with storing and deliver-
ing lubricating oil to and from the engine. These items include the oil filter, oil cooler, oil filler cap/dipstick,
oil pressure sensor/temperature indicator, oil pressure sensor, and oil temperature sensor. For additional
information on the engine oil system components, refer to the Teledyne Continental Motors Model IO-550
Overhaul Manual indexed in the List or Publications in the front of this manual. (Refer to TCM Model IO-
550 Overhaul Manual)
The oil supply is contained in a wet sump attached to the bottom of the crankcase. A conventional dipstick
integral to the oil filler cap is provided for determining oil quantity.
When the crankshaft is turning, oil is drawn through a screen and pick up tube which extends from the
sump to a port in the crankcase. Oil then passes to the inlet of the gear-type, engine-driven oil pump and is
forced under pressure through the pump outlet. A pressure relief valve prevents excessive oil pressure by
allowing excess oil to be returned to the sump. After exiting the pump, the pressurized oil enters a full-flow
filter and is passed on to the oil cooler. If the filter element becomes blocked, a bypass relief valve will open
to permit unfiltered oil to flow to the engine. As the oil enters the oil cooler, an oil temperature control unit
directs the flow in one of two directions; when the oil is cold, the oil temperature control unit opens and
bypasses most the oil around the cooler, as the oil warms, the oil temperature control unit closes off the
cooler bypass and forces the oil through the cooler core. In operation, the oil temperature control unit mod-
ulates to maintain oil temperature in the normal range of approximately 170° F.
After leaving the cooler, the oil enters the crankcase where various channels and passageways direct it to
the bearing surfaces and other areas requiring lubrication and cooling such as the valve lifters, inner
domes and lower cylinder walls. Oil within the engine gravity drains back into the sump.
30 Nov 2000