International C135 Specifications
| Engine Model: International Harvester C135 |
| Engine Type: 4-stroke in-line 4-cylinder liquid-cooled gasoline |
| Total Displacement: 135 cu.in (2.21 L) |
| Rated Engine Power: 35-45 Hp (27-33 kW) at 2000 rpm |
| Fuel System Type: Updraft carburetor |
____________________________________________________________________________________
The International C135 is a 2.2-liter,
naturally aspirated, four-cylinder gasoline engine produced by
International Harvester (IH) during the late 1950s and 1960s. This
powerplant represents a robust and serviceable design philosophy from an
era when agricultural and industrial equipment demanded reliability,
ease of maintenance, and high torque at low engine speeds. The C135 was
a popular choice for light-to-medium duty tractors and various
stationary industrial power units, forming the backbone of many farm
operations across North America.
The engine employs an overhead valve (OHV) configuration with pushrods,
a design chosen for its balance of mechanical simplicity and breathing
efficiency compared to flathead layouts. A defining characteristic of
the C-135 is its replaceable wet-sleeve cylinder liner construction, an
advanced feature for its class that permitted engine rebuilding without
complete block replacement.
The engine operates with a relatively low compression ratio of 7.5:1,
allowing it to run on low-octane fuels while producing peak torque at a
low 1,200 rpm. This torque characteristic, combined with a mechanical
flyweight governor, makes the C135 exceptionally suited for sustained
load applications such as ploughing, mowing, and powering belt-driven
implements. International Harvester installed this engine most notably
in the Farmall 404, 330, and 340 tractors, where it delivered dependable
service for thousands of hours.
The International C135 is a four-stroke, spark-ignition, inline
four-cylinder gasoline engine. The engine block is configured for a
naturally aspirated induction system without any supercharging or
turbocharging apparatus. Total displacement measures 135 cubic inches,
equivalent to 2.21 liters. The bore dimension is 3.250 inches (82.5 mm),
and the stroke dimension is 4.062 inches (103.2 mm). This long-stroke
design (undersquare) prioritizes low-rpm torque production over high-rpm
power. The compression ratio is fixed at 7.5:1. The firing order
sequence is 1-3-4-2, a standard configuration for inline four-cylinder
engines that ensures balanced primary and secondary forces.
Gross power output ranges from 35 to 45 horsepower at the flywheel,
depending on specific governor settings and carburetion. Power take-off
(PTO) power, measured at the tractor’s PTO shaft, is 35 to 38
horsepower. Drawbar power, representing force available at the hitch, is
31 to 33 horsepower. The rated engine speed for tractor applications is
2,000 rpm. Industrial and stationary power unit configurations permit
operation up to 2,400 rpm. Maximum torque reaches 115 lb-ft at 1,200
rpm. Idle speed is 450 to 500 rpm.
The cylinder block is constructed from cast iron, providing inherent
rigidity, vibration damping, and wear resistance. A defining engineering
feature of the C-135 block is its wet-sleeve cylinder liner design. Each
of the four cylinders contains a removable sleeve that contacts the
engine coolant directly on its outer surface.
This sleeve design serves multiple purposes: it allows individual
cylinder replacement without boring the entire block, it simplifies
engine rebuilding to standard specifications, and it provides a superior
sealing surface for the piston rings. The sleeves are held in place by
the cylinder head gasket when the head is torqued down. The block
incorporates a three-main-bearing crankshaft support structure, meaning
the crankshaft rotates on three bearing journals.
This configuration, while less common than five-main-bearing designs,
was adequate for the engine’s rated speed and torque output. The skirt
of the block extends below the crankshaft centerline, contributing to
structural rigidity. The water jacket surrounds the entire length of the
cylinder sleeves to maximize heat transfer away from the combustion
zone.
The cylinder head is a separate cast-iron component bolted to the top of
the cylinder block. It houses the overhead valve (OHV) mechanism, which
comprises the valves, valve springs, retainers, rocker arms, and
pushrods. The valvetrain is actuated by a camshaft located within the
cylinder block, driven by gears from the crankshaft.
Camshaft lobes contact mechanical lifters (tappets), which push hollow
pushrods upward. The pushrods transmit motion to the rocker arms, which
pivot to open the valves against spring pressure. The cylinder head
contains two valves per cylinder, one intake and one exhaust, for a
total of eight valves. Intake and exhaust valves are positioned in a
straight line along the cylinder head.
The combustion chamber is a wedge design, promoting turbulence for
thorough air-fuel mixing. Valve lash (clearance) is adjustable via set
screws on the rocker arms. Specification for both intake and exhaust
valves, measured with the engine at operating temperature, is 0.014
inches (0.36 mm). This equal valve lash setting simplifies maintenance.
Valve seat angles are 45 degrees, standard for engines of this era.
The fuel system employs an updraft carburetor, manufactured by Carter or
Marvel-Schebler depending on the production date and application. In an
updraft configuration, air enters the carburetor from below, drawing
fuel upward through the venturi before entering the intake manifold. A
mechanical fuel pump, mounted on the engine block and actuated by an
eccentric lobe on the camshaft, draws fuel from the tank and delivers it
to the carburetor float bowl.
The carburetor incorporates a float-type fuel metering system, an idle
circuit, a main metering circuit, and a power enrichment circuit. A
manual choke is provided for cold starting. The intake manifold is a
cast-iron unit with a single inlet passage that splits to serve all four
cylinders. A critical component integrated into the fuel system is the
mechanical flyweight governor.
This governor is gear-driven from the engine camshaft and senses engine
speed via centrifugal force acting on weights. The governor linkage
connects directly to the carburetor throttle plate, automatically
adjusting the throttle opening to maintain a preset engine speed under
varying loads. This governor system is essential for tractor and power
unit applications where constant-speed operation is required.
The lubrication system is a pressurized, wet-sump design using a
gear-type oil pump. The oil pump is mounted inside the oil pan and
driven by a shaft from the distributor drive gear. Oil is drawn from the
sump through a screened pickup tube and forced through a full-flow oil
filter.
After filtration, oil travels through internal drillings in the cylinder
block to reach the main bearings, connecting rod bearings, and camshaft
bearings. Excess oil from the main bearings is directed through passages
to lubricate the valve train components, including the camshaft lobes,
lifters, pushrod ends, and rocker arms. The system capacity with an oil
filter change is 5.0 US quarts (4.7 liters).
Operating oil pressure at rated engine speed (2,000 rpm) should register
between 20 and 35 psi. A pressure relief valve prevents excessive
pressure during cold starts or high-rpm operation. Crankcase ventilation
is provided by a road draft tube, which relies on airflow past the
tube’s opening to draw combustion blow-by gases out of the crankcase.
The cooling system is a thermosiphon or pump-assisted water circulation
design, depending on the specific installation. Early tractor
applications relied partially on thermosiphon action (hot water rising
to the radiator and cool water falling back to the block), but most C135
engines feature a centrifugal water pump for forced circulation.
The water pump is belt-driven from the crankshaft pulley. Coolant flows
from the lower radiator hose into the water pump, through the cylinder
block water jacket, upward into the cylinder head, and then out through
the upper radiator hose. The wet-sleeve liner design maximizes coolant
contact with each cylinder’s combustion region. A wax-pellet or
bellows-type thermostat regulates operating temperature.
The thermostat opening temperature range is 160°F to 180°F (71°C to
82°C). The total cooling system capacity, including the engine block,
cylinder head, radiator, and heater (if equipped), is 13.0 to 14.0 US
quarts (12.3 to 13.2 liters). A fan attached to the water pump pulley
draws air through the radiator core to dissipate heat.
The mechanical flyweight governor is gear-driven from the engine
camshaft. Governor weights act against a spring-loaded thrust bearing.
The operator sets the desired engine speed via a hand lever, which
adjusts spring tension. When engine load increases, speed drops, the
weights move inward, and the governor opens the throttle. When load
decreases, speed rises, the weights move outward, and the governor
closes the throttle.
| Ignition and Electrical System |
Ignition System: The ignition system is a battery-and-coil design. A
12-volt electrical system with negative ground became standard on later
production models (early versions used 6-volt positive ground). The
distributor is gear-driven from the camshaft and contains breaker
points, a condenser, a centrifugal advance mechanism, and a vacuum
advance unit. Breaker point gap is set to 0.020 inches (0.51 mm). The
ignition coil converts battery voltage to high voltage for the spark
plugs. Spark plug gap is 0.025 inches (0.64 mm). Ignition timing at idle
speed (450-500 rpm) is set to 2 degrees before top dead center (BTDC).
Centrifugal advance increases timing to 22 degrees BTDC at full engine
speed.
Electrical System: A belt-driven generator (or alternator on later
models) charges the battery. A voltage regulator controls charging
output to prevent overcharging. A starter motor engages with the
flywheel ring gear to crank the engine for starting.
The complete engine assembly, including the intake and exhaust
manifolds, carburetor, governor, distributor, water pump, and generator,
has an overall length of 30 inches (762 mm), a width of 22 inches (559
mm), and a height of 28 inches (711 mm). The dry weight of the long
block (cylinder block with crankshaft, pistons, connecting rods,
camshaft, and cylinder head) is 425 pounds (193 kg). This weight
increases to 475 pounds (215 kg) with the addition of manifolds,
carburetor, governor, starter, generator, water pump, and flywheel.
Service intervals for the C135 are based on operating hours. Engine oil
and filter should be changed every 100 hours of operation. Oil viscosity
selection depends on ambient temperature: SAE 10W-30 for year-round use,
SAE 30 for summer temperatures above 32°F (0°C), and SAE 10W for winter
temperatures below 32°F (0°C). The oil filter is a spin-on or
cartridge-type full-flow unit.
Valve lash adjustment is required every 300 hours. The breaker point gap
requires inspection and adjustment every 250 hours. Spark plug
replacement interval is 500 hours. The distributor cap and rotor should
be inspected for corrosion and cracking every 500 hours. The cooling
system requires draining, flushing, and refilling with a fresh mixture
of ethylene glycol antifreeze and distilled water (50/50 ratio) every
two years.
Thermostat replacement is recommended if the engine fails to reach
operating temperature or overheats. The air cleaner is an oil-bath type
requiring cleaning of the oil cup and replacement of the air cleaner oil
every 100 hours under dusty conditions. The fuel filter (inline screen
or sediment bowl) requires cleaning every 200 hours. The governor oil
level (separate sump on some variants) should be checked every 100
hours.
Critical fasteners demand precise torque values to ensure reliable
sealing and prevent component failure. Cylinder head bolts receive a
final torque of 80 to 90 lb-ft (108 to 122 Nm) using a gradual,
crosswise tightening sequence. Connecting rod cap bolts are torqued to
45 to 50 lb-ft (61 to 68 Nm). Main bearing cap bolts receive 75 to 85
lb-ft (102 to 115 Nm). Flywheel bolts are tightened to 55 to 65 lb-ft
(75 to 88 Nm). Crankshaft pulley bolt torque is 100 to 110 lb-ft (136 to
149 Nm).
Rocker arm shaft bracket bolts are secured to 25 to 30 lb-ft (34 to 41
Nm). Intake and exhaust manifold nuts receive 25 to 30 lb-ft (34 to 41
Nm). Spark plugs are torqued to 25 to 30 lb-ft (34 to 41 Nm) into a
cast-iron cylinder head. The oil drain plug requires 20 to 25 lb-ft (27
to 34 Nm). The water pump mounting bolts are set to 15 to 20 lb-ft (20
to 27 Nm). The governor mounting bolts receive 25 to 30 lb-ft (34 to 41
Nm).
The International C-135 engine powered a range of International
Harvester agricultural and industrial equipment. Primary tractor
applications include the Farmall 404 (produced 1961-1967), the Farmall
330 (produced 1961-1964), and the Farmall 340 (produced 1958-1963). In
these tractors, the C135 served as the standard gasoline power unit. The
engine also appeared in the International 404 utility tractor (produced
1961-1968).
Industrial applications include the International 3400 industrial
tractor and various stationary power units used to drive pumps,
generators, conveyors, and other belt-driven machinery. The C135 was
offered in some International light-duty trucks of the early 1960s,
though the C153 (a larger-bore derivative) was more common in truck
applications. This engine is distinct from the smaller International
C123 (2.0-liter) and the larger C153 (2.5-liter) engines, which share
the same basic block architecture and wet-sleeve design but differ in
bore diameter.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
