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International C153 Engine

The International Harvester C153 is a heavy-duty, inline four-cylinder internal combustion engine operating on gasoline or liquid petroleum (LP) gas. Introduced by International Harvester to power agricultural and industrial machinery, such as the Farmall 504 tractor, various windrowers, combines, and industrial forklifts, it represents the final evolution of the iconic C113/C123/C135 engine family. Unlike its predecessors, which utilized wet-sleeve cylinder liners, the C153 features a sleeveless, "parent-bore" cast iron block layout. This design allowed IH engineers to achieve maximum displacement within a compact external envelope by boring the cylinders directly into the block casting. Known for exceptional breathing efficiency and high power output for its dimensional class, the engine is built for high-idle operations but demands disciplined maintenance to combat premature bore wear during continuous heavy tillage or industrial operation.

The engine uses an overhead valve (OHV) arrangement with two valves per cylinder (one intake, one exhaust) actuated by a gear-driven camshaft via pushrods and rocker arms. Firing Order: 1-3-4-2. Bore Diameter: 3.375 inches (85.73 mm) parent metal diameter. Piston Stroke: 4.250 inches (107.95 mm). Total Displacement: 152.1 cubic inches (2.5 Liters).

The fuel delivery architecture is configured for either gasoline or LP gas applications. In gasoline variations, fuel feeds through a sediment bowl into a single-barrel, side-draft updraft carburetor, which is regulated by a mechanical flyweight governor to ensure throttle compensation under fluctuating machine loads. LP variations replace the carburetor assembly with an integrated LP gas regulator/vaporizer unit and a specialized gas carburetor mixer. Air induction travels through an oil-bath or dry-element air cleaner system before entering the intake manifold.

The lubrication circuit relies on a positive-displacement, gear-type oil pump driven directly off the camshaft. The pump draws oil from the oil pan through a floating intake screen and routes it through a full-flow oil filter element to main, connecting rod, and camshaft bearings, with a top-end feed delivering oil directly to the rocker arm shaft assembly. The engine uses a pressurized, liquid-forced circulation system. A belt-driven centrifugal water pump forces coolant through the sleeveless engine block jacket and cylinder head casting, through a conventional high-capacity radiator, and regulates thermal ranges via a high-temperature thermostat assembly.

General Technical Data

Engine Specifications

Engine Model ............... International Harvester C153
Engine Type ............... 4-cycle inline 4-cylinder spark-ignition liquid-cooled gasoline/LP
Number of Cylinders ............... 4
Cylinder Arrangement ............... In-line
Engine Bore, in (mm) ............... 3.375 (85.7)
Engine Stroke, in (mm) ............... 4.250 (108.0)
Displacement, cu.in (L) ............... 152.1 (2.5)
Rated Engine Power, hp (kW) ............... 45-58 (33.6-43.3)
Rated Engine Speed, rpm ............... 2200-2400
Peak Torque ............... 145 lb-ft (196.6 Nm) at 1400 rpm
Idle Speed ............... 600-700 rpm
Operating Speed ............... 2200 rpm
Compression Ratio ............... 7.3:1-7.8:1
Firing Order ............... 1-3-4-2
Valve Configuration ............... Overhead valve pushrod actuation layout
Valves Per Cylinder ............... 2 overhead valves per single cylinder
Camshaft Drive Type ............... Gear-driven helical gear pairing interface
Cylinder Block Type ............... Cast iron parent-bore non-sleeved
Cylinder Head Type ............... Cast iron overhead valve structural unit
Lubrication System ............... Full-pressure internal lubrication circuit
Oil Pump Type ............... Gear-driven internal assembly
Oil Filter Type ............... Full-flow, spin-on cartridge elements
Cooling System ............... Liquid-cooled centrifugal circuit forced circulation
Water Pump Type ............... Belt-driven, centrifugal housing module
Air Cleaner Type ............... Oil bath or dry element dual-stage alternative
Ignition System ............... Mechanical distributor battery ignition module unit
Spark Plug Gap, in (mm) ............... 0.025 (0.635)
Breaker Point Gap, in (mm) ............... 0.020 (0.508)
Ignition Timing Setting ............... 2 deg BTDC
Starting System ............... Electric Starter motor interaction
Electrical System ............... 12V negative ground

Fuel System

Fuel Delivery Unit ............... Updraft single throat carburetion system
Carburetor Model ............... Zenith or Marvel Schebler
Fuel Pump Pressure, psi (kPa) ............... 3.5-5.0 (24.1-34.5)
Float Setting Level, in (mm) ............... 0.25 (6.35)
Fuel Filter Placement ............... Inline element canister combined sediment bowl
Sediment Bowl Design ............... Glass body assembly visual inspection water trap system
LP Gas Regulator Type ............... Two-stage vaporizing atmospheric pressure control module
LP Gas Carburetor Model ............... Low restriction air fuel gas blender valve structural system
Throttle Shaft Clearance, in (mm) ............... 0.002-0.004 (0.051-0.102)
Intake Manifold Preheater ............... Exhaust gas heat riser flap selector seasonal temp valve
Governor Type ............... Mechanical centrifugal flyweight governor assembly
Governor Regulation ............... Mechanical variable speed regulation control

Dimensions and Weight

Overall Length, in (mm) ............... 32.5 (825)
Overall Width, in (mm) ............... 21.3 (540)
Overall Height, in (mm) ............... 29.8 (755)
Dry Weight, lbs (kg) ............... 485 (220)
Shipping Weight, lbs (kg) ............... 530 (240)

Maintenance Data

Service Information

Compression Pressure Range, psi (bar) ............... 120-140 (8.3-9.6)
Oil Pressure Rated Speed, psi (bar) ............... 30-45 (2.1-3.1)
Oil Pressure Low Idle, psi (bar) ............... 10 (0.69)
Cooling System Thermostat Opening, F (C) ............... 165 (73.9)
Cooling System Thermostat Full Open, F (C) ............... 190 (87.8)
Radiator Cap Pressure Rating, psi (kPa) ............... 7.0 (48.3)
Fan Belt Tension Deflection, in (mm) ............... 0.50 (12.7)
Intake Valve Clearance, in (mm) ............... 0.014 (0.356)
Exhaust Valve Clearance, in (mm) ............... 0.014 (0.356)

Engine Oil and Coolant

Engine Oil Type .................. SAE 30, SAE 10W, or 10W-30
API Service Classifications ......................... SF/CC or higher
Engine Oil Capacity, qt (L) ............... 5.0 (4.7)
Cooling System Volume, qt (L) ............... 15.0 (14.2)

Service Intervals

Change oil and filter ............... Every 100 hours
Inspect air filter ............... Every 50 hours
Valve clearance adjustment ............... Every 500 hours
Fuel system inspection ............... Every 1000 hours
Change coolant ............... Every 1000 hours
Spark plug replacement ............... Every 500 hours
Check ignition system ............... Every 500 hours

Service Specifications

Cylinder Bore Inside Diameter ............... 3.375 in (85.725 mm)
Crankshaft Journal Outside Diameter ............... 2.6235 to 2.6245 in (66.637 to 66.662 mm)
Crank Pin Outside Diameter ............... 2.123 to 2.124 in (53.924 to 53.950 mm)
Crankshaft End Play ............... 0.004 to 0.008 in (0.102 to 0.203 mm)
Intake Valve Stem Outside Diameter ............... 0.341 in (8.661 mm)
Exhaust Valve Stem Outside Diameter ............... 0.340 in (8.636 mm)
Intake Valve Guide Inside Diameter ............... 0.343 to 0.344 in (8.712 to 8.738 mm)
Exhaust Valve Guide Inside Diameter ............... 0.343 to 0.344 in (8.712 to 8.738 mm)
Intake Valve Stem to Guide Clearance ............... 0.002 to 0.0035 in (0.051 to 0.089 mm)
Exhaust Valve Stem to Guide Clearance ............... 0.003 to 0.0045 in (0.076 to 0.114 mm)
Intake Valve Spring Free Length ............... 2.156 in (54.762 mm)
Exhaust Valve Spring Free Length ............... 2.156 in (54.762 mm)
Intake Cam Height ............... 1.583 in (40.208 mm)
Exhaust Cam Height ............... 1.583 in (40.208 mm)
Piston Pin Outside Diameter ............... 0.859 in (21.819 mm)
Piston Pin to Piston Bore Clearance ............... 0.0001 to 0.0003 in (0.0025 to 0.0076 mm)
Top Ring Side Clearance ............... 0.002 to 0.004 in (0.051 to 0.102 mm)
Second Ring Side Clearance ............... 0.002 to 0.004 in (0.051 to 0.102 mm)
Oil Ring Side Clearance ............... 0.0015 to 0.0035 in (0.038 to 0.089 mm)
Top Ring End Gap ............... 0.010 to 0.020 in (0.254 to 0.508 mm)
Second Ring End Gap ............... 0.010 to 0.020 in (0.254 to 0.508 mm)
Oil Ring End Gap ............... 0.010 to 0.020 in (0.254 to 0.508 mm)

Tightening Torque Specs

Cylinder Head Bolts ............... 80-90 lb-ft (108-122 Nm)
Connecting Rod Cap Nuts ............... 45-50 lb-ft (61-68 Nm)
Main Bearing Cap Bolts ............... 75-85 lb-ft (102-115 Nm)
Flywheel Bolts ............... 55-65 lb-ft (75-88 Nm)
Rocker Arm Assembly Bolts ............... 25-30 lb-ft (34-41 Nm)
Intake Manifold Nuts ............... 25-30 lb-ft (34-41 Nm)
Exhaust Manifold Nuts ............... 25-30 lb-ft (34-41 Nm)
Spark Plugs ............... 20-25 lb-ft (27-34 Nm)
Oil Pan Bolts ............... 10-12 lb-ft (14-16 Nm)
Water Pump Bolts ............... 20-25 lb-ft (27-34 Nm)
Timing Gear Cover Bolts ............... 12-15 lb-ft (16-20 Nm)
Carburetor Flange Nuts ............... 15-18 lb-ft (20-24 Nm)
Governor Cover Bolts ............... 10-12 lb-ft (14-16 Nm)
Crankshaft Pulley Bolt ............... 125-135 lb-ft (169-183 Nm)

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• International Engines Specs
  
• International BC144 Specs
  
• International C113 Specs
  
• International C135 Specs
  
• International C152 Specs
  
• International C157 Specs
  

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