TM-9-2815-213-34
ENGINE, DIESEL, WITH ACCESSORIES CUMMINS MODEL V8-300 (2815-910-8217)
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL (INCLUDING DIRECT SUPPORT AND GENERAL SUPPORT REPAIR PARTS LIST AND DEPOT MAINTENANCE ALLOWANCES)
FEBRUARY 1972
TM-9-2815-213-34 - Page 13 of 192
*TM 9-2815-213-34
bearing cap to absorb crankshaft thrust loads. Dowel
pins are used to position each dowel pin half-ring.
(5)
Crankshaft gear.
A crankshaft gear is keyed to
the rear end of the crankshaft driving the gear train for
the camshaft and air compressor.
(6)
Vibration damper.
A vibration damper is
mounted to the forward end of the crankshaft to dampen
crankshaft vibrations. The unit consists of a rubber
damper hub and inertia member, both of which have
alinement marks and are matched when assembled. The
unit is further matched with alinement marks when
installed on the crankshaft to aid in dynamic balance.
(7)
Connecting rod with piston pin bushing.
The
connecting rod assemblies are two piece, I-beam, steel-
forgings split at the crankshaft end. Two piston pin
bushings are press fit into the rod at the piston end for
the floating-type piston pin. The pin is held in the piston
by two retaining rings.
(8)
Connecting
rod
bearings.
Connecting rod
bearings are steel backed, copper-lead, insert type, split
on the diameter. They are interchangeable and are
installed without reaming, scraping, or use of shims.
(9)
Pistons.
Aluminum alloy pistons are "barrel
ground", which provides a greater diameter at the thrust
surface than at the piston pin bosses. Pistons have three
piston rings (two compression and one oil). Compression
rings are located in the bottom groove. All rings are
located above the piston pin boss.
(10)
Camshaft.
A single camshaft positioned in the V-
section of the cylinder block directly above the
crankshaft, controls all valve and injector operations for
both banks. It is supported by five camshaft bushings
installed in the cylinder block. A camshaft thrust bearing
is installed at the gear (rear) end of the camshaft to
absorb thrust loads. Drilled oil passages in the cylinder
block lubricate the five camshaft bearings. The camshaft
gear is pressed and keyed to the rear of the camshaft
and is meshed (marked "O") with the crankshaft gear.
The camshaft is driven at one-half crankshaft speed.
The camshaft gear is meshed with the fuel pump and air
compressor drive gear at the upper rear portion of the
engine. The camshaft has twenty-four cams, eight
operate exhaust valves, eight operate intake valves, and
eight operate fuel injectors.
(11)
Cylinder
head.
Two
cylinder heads (one each
bank) are attached to the cylinder
block with 16 hold-down capscrews. Injectors and valves
are mounted in the cylinder head. Rocker levers and
bearing assemblies are located on top of each head on
pedestals.
(12)
Valves, valve springs, valve rocker levers,
bearings, and fuel injectors.
(a)
There are dual intake and exhaust valves
for each cylinder. Sixteen valve rocker levers with
bearing assemblies are mounted on the rocker lever
shafts. A cross-head moves two valves in unison from
pressure excited by the rocker lever. Right and left
movement comes from a push tube connected to the
cam followers. The cam followers ride on the lobe of the
camshaft. The valves and their companion crossheads
operate in replaceable guides. Valve springs are secured
to valve stems by valve spring retainers and locks.
Rocker lever shafts are supported by four rocker lever
brackets mounted on the cylinder heads.
(b)
Eight injector rocker levers and bearing
assemblies are mounted on the rocker arm shaft along
with the valve rocker assemblies. The injector is actuated
by the same method used to actuate the valve.
(13)
Flywheel with Ring Gear Assembly.
The flywheel
with ring gear assembly consists of a cast iron flywheel
with a replaceable steel ring gear. The flywheel is
attached to the rear of the crankshaft by means of a
crankshaft adapter using eight capscrews. The ring gear
meshes with the starter gear during the cranking
operation.
(14)
Oil Pump Assembly.
The oil pump installed
within the oil pan is of the positive placement gear type in
mesh with a gear train. Oil is drawn from the oil pan
sump through the oil pump inlet pipes (both suction and
scavenger lines) to the pump inlet ports. Oil is pumped
from the pressure pump under pressure through the
discharge port into various drillings in the block, cylinder
head, crankshaft, and rocker levers lubricating the
engine. The scavenger evacuates oil from the rear of the
oil pan and returns it to the main sump when the vehicle
is operating on steep grades. Oil pressure is maintained
by a regulator installed in the oil pressure pump.
1-5.
Tabulated Data
Refer to TM 9-2320-206-20 for tabulated data pertaining
to general characteristics and performance of the engine
assembly.
a.
General.
Manufacturer
Cummins Engine Company, Inc.
1-5
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