Cessna 17273274 Pilot Operating Handbook page 135

SECTION 7
&
AIRPLANE SYSTEMS DESCRIPTIONS
of this gage are presented in Section 9, Supplements.
NEW ENGINE BREAK-IN AND OPERATION
The engine underwent a run-in at the factory and is ready for the full
I
range of use. It is, however, suggested that cruising be accomplished at a
minimum of 75% power until a total of 50 hours has accumulated or oil
consumption has stabilized. This will ensure proper seating of the rings.
ENGINE OIL SYSTEM
Oil for engine lubrication is supplied from a sump on the bottom of the
engine. The capacity of the engine sump is six quarts (one additional quart
is required if a full flow oil filter is installed). Oil is drawn from the sump
through an oil suction strainer screen into the engine-driven oil pump.
From the pump, oil is routed to a bypass valve.
valve allows the oil to bypass the oil cooler and go directly from the pump
to the oil pressure screen (full flow oil filter if installed).
bypass valve routes the oil out of the accessory housing and into a flexible
hose leading to the oil cooler on the right, rear engine baffle. Pressure oil
from the cooler returns to the accessory housing where it passes through
the pressure strainer screen (full flow oil filter, if installed). The filter oil
then enters a pressure relief valve which regulates engine oil pressure by
allowing excessive oil to return to the sump while the balance of the oil is
circulated to various engine parts for lubrication. Residual oil is returned
to the sump by gravity flow.
An oil filler cap/ oil dipstick is located at the rear of the engine near the
center. The filler cap/ dipstick is accessible through an access door in the
engine cowling. The engine should not be operated on less than four quarts
of oil. For extended flight, fill to six quarts (dipstick indication only). For
engine oil grade and specifications, ref er to Section 8 of this handbook.
An oil quick-drain valve is available to replace the drain plug on the
bottom of the oil sump, and provides quicker, cleaner draining of the
engine oil. To drain the oil with this valve, slip a hose over the end of the
valve &.nd push upward on the end of the valve until it snaps into the open
7-18
MODEL 172N
If
the oil is cold, the bypass
If
the oil is hot, the
1 July 1979
Revision 1 - 15 November 1979
CESSNA