Rockwell Commander 112 - Carburetor; OIL System; Turbocharger

ROCKWELL
COMMANDER
112/B/TC/TCA
MAINTENANCE MANUAL
SECTION IV
POWER PLANT
AND PROPELLER
CARBURETION SYSTEM
CARBURETOR
a. Connect fuel injection lines to air bleed nozzles.
b. Inspect installation for evidence of crimped lines.
c. Operate auxiliary fuel pump and check fittings
and air bleed nozzles for evidence of leakage.
d. Turn off auxiliary fuel pump and battery switch
and secure cowling.
MODELS 112TC/TCA. These models are equipped
with a Marvel Schebler Type HA-6 side draft, single
barrel, float type carburetor equipped with a manual
altitude mixture control and an idle cut-off. The idle
speed aqjustment is a conventional spring-loaded
needle valve.
MODELS 112TC/TCA. IDLE ADJUSTMENT. Idle
adjustment may be accomplished as follows:
a. Start and warm engine until oil and cylinder
head temperatures are in normal operating range.
b. Check magneto drop, see Section II. If drop is
normal, proceed with idle adjustment.
c. Set idle adjusting needle valve (see Figure 4-6)
so engine idles smoothly.
d. Run up to 2000 RPM to clear engine after each
adjustment before making any additional adjustments.
NOIE
Engine idle speed may vary among
different engines. An engine should
idle smoothly without excessive vibra-
tion, and the idle speed should be high
enough to maintain idling oil pressure
and to preclude any possibility of engine
stoppage in flight when throttle is closed.
MODELS 112TC/TCA. CARBURETOR REMOVAL.
The carburetor may be removed as follow s:
a. Remove lower cowling.
b. Disconnect throttle and mixture linkage.
c. Disconnect and cap all fuel lines at carburetor.
d. Remove bolts from turbocharger adapter and
secure as necessary to allow carburetor removal.
e. Remove nuts holding carburetor to engine,
remove carburetor and install covers on turbocharger
adapter and mounting pad.
MODELS 112TC/TCA. CARBURETOR INSTALLATION
a. Remove covers from mounting pad and turbo-
charger adapter. Install carburetor on mounting
studs and torque as required.
b. Install turbocharger adapter and torque as
required.
c. Uncap and install all fuel lines.
Change 1
When
replacing AI0- 5200 carburetor
with another carburetor of the same
number, assure needle valve assembly
retainer is secured to carburetor with
lockplate as shown in Figure 4- 6.
d.
Connect throttle and mixture control linkage.
e.
NOI.
Check throttle and mixture control
for proper travel.
Install lower cowling.
MODELS 112TC/TCA. CLEANING FUEL STRAINER.
The carburetor fuel strainer should be cleaned at
periodic intervals, to remove strainer, proceed as
follows:
a. Remove safety and remove strainer from car-
buretor (see Figure 4-6).
b. Wash strainer in approved solvent.
c. Check strainer for deformation or breaks.
d. Clean strainer chamber of any foreign material.
e. Reinstall strainer, tighten and safety.
TURBOCHARGER
MODELS 112TC/TCA. A complete turbocharger sys-
tern, installed on the aft end of the engine consists of
a
turbine and compressor assembly and an overboost
pressure relief valve. The turbocharger is utilized
to increase the power output and efficiency of the en-
gine by supplying compressed air to the engine intake
system. The power to drive the turbocharger is ex-
tracted from energy in the exhaust gas. A manually
controlled (interconnected with throttle) exhaust waste-
gate valve assembly determines the amount of boost
supplied to the engine. When open, the valve allows
exhaust to bypass the turbine and flow directly over-
board. In the closed position, the wastegate valve
diverts the exhaust gases through the turbine assem-
bly, increasing its speed and resulting in more output
of induction air from the compressor, since it is con-
nected to the opposite end of the turbine shaft.
OIL SYSTEM
The engine is equipped with a wet sump, pressure
operated oil system. The main bearings, connecting
rod bearings, camshaft bearings, valve tappets, and
push rods, are lubricated by positive pressure. The
pistons, piston pins, cams, cylinder walls, valve
rockers, valve stems and other internal moving parts
are lubricated by oil collectors and oil spray. The
oil pump, located in the accessory housing, draws oil
4-11
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**unofficial copy**