Cat 3208 Specifications
| Engine Model: Caterpillar 3208 |
| Engine Type: 4-cycle 8-cylinder naturally aspirated liquid-cooled diesel |
| Total Displacement: 636 cu.in (10.4 L) |
| Rated Engine Power: 175-210 Hp (135-160 kW) at 2200 rpm |
| Fuel System Type: Direct fuel injection |
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The Caterpillar 3208 is a V-8 configuration,
10.4-liter diesel engine that achieved widespread recognition for its
compact design, smooth operation, and versatile application across
multiple industries. As a naturally aspirated engine, it delivers power
and torque through displacement and mechanical simplicity rather than
forced induction. The 3208 is characterized by its 90-degree V-block,
replaceable wet cylinder liners, and a mechanically governed fuel
system.
Its design prioritizes accessibility for service, with grouped
components and a shallow profile that facilitated installation in tight
engine compartments. This engine became a mainstay in medium-duty
trucks, marine vessels, and industrial equipment, earning a reputation
for durability and straightforward maintenance. The 3208’s production
run represented a successful application of V-8 architecture in the
commercial diesel sector.
Engine Type: 90-Degree V-8, Four-Stroke Cycle Diesel.
Aspiration: Naturally Aspirated.
Displacement: 10.4 Liters (636 cubic inches).
Bore: 114.3 mm (4.5 inches).
Stroke: 127.0 mm (5.0 inches).
Engine Power (Industrial/Truck): 175-210 HP (135-160 kW).
Engine Power (Marine): 157-324 bkW (210-435 bhp) at 2800 RPM.
Compression Ratio: 16.5:1.
Firing Order: 1-2-7-8-4-5-6-3.
Rotation (Viewed from Flywheel End): Counterclockwise.
Governor Type: Mechanical, variable speed or all-speed.
Emission Certification: Pre-Tier/Stage I mechanical engine.
The cylinder block is a compact, 90-degree V-style cast iron structure.
It incorporates replaceable wet-type cylinder liners for each cylinder.
The liners are pressed into the block and sealed at the top with a
copper gasket under a precision-machined flange.
The block design places the two cylinder banks at a 90-degree angle,
allowing for a shorter, more rigid crankshaft compared to an inline
engine of similar displacement. Main bearing caps are made of nodular
iron and secured by two bolts each. The camshaft is centrally located in
the "V" of the block, driven by the crankshaft via gears.
Two separate cast iron cylinder heads are used, one for each cylinder
bank. Each head employs a two-valve-per-cylinder design - one intake and
one exhaust. Valve seat inserts are hardened for wear resistance. Valve
guides are pressed into the head and are replaceable.
Valve actuation is via pushrods and rocker arms; the rocker arms are
shaft-mounted on each cylinder head. Valve lash is adjusted manually
using a screw and locknut on each rocker arm. The cylinder head gaskets
are composite designs. Each head is secured by ten bolts.
The engine utilizes a direct injection, mechanically controlled fuel
system. The system centers on a single, camshaft-driven rotary
distributor-type injection pump, such as a Bosch or American Bosch
model. This pump meters and times fuel delivery, distributing
high-pressure fuel sequentially to individual multi-hole injectors in
each cylinder via steel fuel lines.
Injection timing is adjustable. A mechanical diaphragm-type lift pump
transfers fuel from the tank. The fuel circuit includes a primary
sediment bowl/water separator and a secondary spin-on fuel filter. This
system is mechanically straightforward and field-serviceable.
Lubrication is provided by a gear-type oil pump driven from the
crankshaft gear train. Oil is drawn from the sump through a pickup tube
and screen, then forced through a full-flow, spin-on oil filter mounted
on the engine's left side. A pressure relief valve protects the system.
Filtered oil is directed to the main oil gallery and subsequently
supplied to the crankshaft main and connecting rod bearings, the
camshaft bearings, and the valve gear via hollow pushrods. The system is
designed for stable pressure and volume. An oil cooler is integrated
into the system on most models.
Coolant circulation is managed by a single centrifugal water pump,
gear-driven from the front of the engine. The pump is centrally located
at the front of the "V" and feeds coolant into two separate passages -
one for each cylinder bank. Coolant flows through passages in the
cylinder blocks and cylinder heads.
A single wax-pellet thermostat regulates overall engine temperature. The
cooling system is designed for connection to a radiator or heat
exchanger of adequate capacity. The V-8 layout allows for efficient
coolant flow and heat distribution.
Starting System: 12-volt or 24-volit electric starting motor. Charging
System: A brushless alternator, commonly rated between 65 and 105
amperes, driven by a V-belt from the crankshaft pulley.
Air Intake System: A dry-type air cleaner, often a single cylindrical or
dual-element design, with a service indicator. The intake manifold is a
cast aluminum unit located in the valley between the cylinder banks.
Exhaust System: Separate cast iron exhaust manifolds are used for each
cylinder bank, routing exhaust gases to the outside of the engine "V".
Dimensions are configuration-dependent. For an industrial or truck
engine, approximate length is 1143 mm (45.0 inches), width is 876 mm
(34.5 inches), and height is 1054 mm (41.5 inches). The compact V-8
design provides a favorable power-to-size ratio. The net dry engine
weight, without fluids but including standard accessories like
alternator and starter, ranges from 722 kg to 899 kg (1592 lb to 1982
lb). The weight variation corresponds to different horsepower ratings,
which involve changes in components like pistons and connecting rods.
Engine Oil Grade: Use Caterpillar Diesel Engine Oil (DEO) or an
equivalent oil meeting API CD, CE, or CF-4 classifications. SAE 15W-40
is standard for general use. Oil Change Interval: Determined by service
hours and conditions. Under normal conditions, intervals of 250 hours
are standard. Severe-duty cycles in dusty or high-load applications
necessitate more frequent changes, potentially at 150-hour intervals.
Oil System Capacity: Total refill capacity, including a filter change,
is 17.0 Liters (4.5 US gallons). Confirm final level using the dipstick.
Cooling System Capacity: Total cooling system capacity, including
radiator, is approximately 34.0 Liters (9.0 US gallons).
Fuel Filter: Replace the secondary fuel filter element every 250 hours.
The primary sediment bowl should be drained of water regularly. Air
Filter: Service or replace the element based on the restriction
indicator. Operating in dusty conditions requires daily checks of the
indicator. Valve Lash Adjustment (Cold): Intake: 0.38 mm (0.015 in).
Exhaust: 0.76 mm (0.030 in). Adjust at initial break-in and every
subsequent 1000 hours of operation.
Engine Coolant: Use a 50/50 mixture of ethylene glycol antifreeze and
clean, demineralized water. Maintain proper concentration of
supplemental coolant additive (SCA) to prevent liner pitting and scale
formation.
Cylinder Head Bolts: Tighten in a specific three-step sequence. Final
torque: 190 Nm (140 lb-ft).
Main Bearing Cap Bolts: Tighten to 160 Nm (118 lb-ft).
Connecting Rod Cap Bolts: Tighten to 125 Nm (92 lb-ft), then tighten an
additional 60 degrees.
Flywheel Housing-to-Block Bolts: Tighten to 75 Nm (55 lb-ft).
Flywheel-to-Crankshaft Bolts: Tighten to 160 Nm (118 lb-ft).
Injector Clamp Bolt: Tighten to 35 Nm (26 lb-ft).
Oil Pan Bolts: Tighten to 41 Nm (30 lb-ft).
Oil Filter Cartridge: Hand-tighten until the gasket contacts the base,
then tighten an additional three-quarters turn. Rocker Arm Shaft Support
Bolts: Tighten to 41 Nm (30 lb-ft).
The Caterpillar 3208 engine saw extensive
and diverse application:
Medium-Duty Trucks: A legendary powerplant in Ford (L-series, C-series),
International (S-series, 1650), GMC, and Chevrolet medium-duty trucks
for dump, refuse, and beverage service. Marine Propulsion: Extremely
popular in pleasure craft, sport fishing boats, and small commercial
workboats for its smooth V-8 operation and reliability. Construction
Equipment: Used in Caterpillar 416, 426, 428 Backhoe Loaders; 920, 930,
950 Wheel Loaders; and various vibratory compactors.
Industrial: Powered generator sets (50-125 kVA), fire pump drives, large
air compressors, and hydraulic power units. Agricultural: Found in large
tractors, combines, and irrigation pumps from manufacturers like John
Deere and Case IH. Buses: Powered numerous school buses and medium-duty
transit coaches.
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