Operating instructions
Table Of Contents
- 1 Introduction
- 2 General Description
- 3 Special Tools and Equipment
- 4 Disassembly
- 5 Cleaning, Repair and Replacement
- 6 Inspection
- Definitions
- Magnetic Particle Inspection
- Critical New Part Dimensions
- Fluorescent Particle Inspection
- Dimensional Inspection
- Protective Coatings
- Crankcase Inspection
- Crankshaft Inspection
- Camshaft Inspection
- Connecting Rod Inspection
- Gear Inspection
- Piston Inspection
- Cylinder Inspection
- Inspection Chart
- Crankcase Stud Heights
- Mag Particle Inspection Procedures
- Table of Limits
- Torque Specifications
- General Torques
- Table of Limits Chart
- 7 Assembly of Subassemblies
- 8 Final Assembly and Test
- 9 IO-520-M
- 10 IO-520-BB, CB and MB
2-9/2-10
2-16. The barrel type hydraulic lifter (See Figure 2-
6) consists of a steel body (1), an expanding spring
(2), and a check valve assembly (3, 4 and 5), a
plunger (6), a socket (7) for pushrod end, and a
retaining ring (8). A groove (9), around outside of
body picks up oil from crankcase supply hole only
when lifter is near outer end of its stroke so engine
pressure will not "pump up" plunger and hold the
valve off its seat. From the exterior groove oil is
directed to interior body groove (11) through hole
(10) and from the interior groove through the hole
(12) to the reservoir (13). Oil is withheld from
reservoir (15) by check valve plate (5) which is
supported by spring (4) of housing (3). The check
valve is opened by outward motion of the plunger
under pressure of the expanding spring whenever a
clearance occurs in the valve train. Thus the body
reservoir is kept full of oil which transmits lifting
force from body of plunger. The plunger and sock-
et are fitted to the body selectively to permit a
calibrated leakage so the lifter will readjust its
effective length after each cycle, while cylinder
valve is closed, to return "lash" in valve train to
zero.
2-17. INDUCTION SYSTEM. The air induction
system used on the IO-520 Series Engines consists
of intake tubes, a balance tube, connecting hoses,
clamp assemblies and a combination air throttle and
fuel metering control. The air throttle assembly
may be located at the rear of the engine supported
by brackets or below the oil sump supported by an
inverted manifold assembly or bolted to a cast oil
sump. The systems are provided with a drain valve
at the lowest point in the manifold assembly to
remove any fuel that may collect there.
The throttle assembly is connected to the elbows at
the rear cylinder intake tubes by connector hoses
and clamps. This assembly is then connected to the
center intake tubes and the center to the front intake
tubes in the same manner. Each intake tube is
attached to the cylinder by a welded flange and four
bolts and is sealed by a gasket. The front cylinder
intake tubes are connected by a balance tube
assembly. The balance tube incorporates a boss and
is supported by a bracket attached to the front of the
oil sump.