Cat 3306 DITA Specifications
| Engine Model: Caterpillar 3306 DITA |
| Engine Type: 4-cycle inline 6-cylinder turbocharged and aftercooled diesel |
| Total Displacement: 638 cu.in (10.5 L) |
| Rated Engine Power: 125-325 Hp (93-243 kW) at 2200 rpm |
| Fuel System Type: Direct fuel injection |
____________________________________________________________________________________
The Caterpillar 3306 DITA is an inline
six-cylinder, 10.5-liter heavy-duty diesel engine, representing a
high-performance and fuel-efficient configuration within the legendary
3300 family. The designation "DITA" stands for Direct Injection,
Turbocharged, Air-to-Air Aftercooled, defining its core technological
features aimed at maximizing power density and thermal efficiency. This
engine is engineered for severe-service applications where reliability,
durability, and high torque output are paramount.
It combines a robust mechanical foundation - including a deep-skirt
block, replaceable wet liners, and cross-bolted main bearings - with
advanced aspiration technology. The air-to-air aftercooler provides a
significant reduction in intake air temperature, allowing for greater
fuel charge density and improved combustion efficiency. The 3306 DITA
became a benchmark for power in mining, heavy construction, and large
generator set applications, renowned for its long service life and
mechanical simplicity.
Engine Type: Inline 6-Cylinder, Four-Stroke Cycle Diesel.
Aspiration: Turbocharged and Air-to-Air Aftercooled (ATAAC).
Displacement: 10.5 Liters (638 cubic inches).
Bore: 121 mm (4.75 inches).
Stroke: 152 mm (6.00 inches).
Engine Power (Industrial): 125-325 HP (93-243 kW).
Engine Power (Marine): 425 hp (317 kW).
Compression Ratio: Ranges from 10.4:1 to 15.0:1, with 10.4:1 being
specific to high-output, low-emission ATAAC configurations.
Firing Order: 1-5-3-6-2-4.
Rotation (Viewed from Flywheel End): Counterclockwise.
Governor Type: Mechanical, variable speed or all-speed.
Emission Certification: Manufactured in configurations meeting pre-Tier
and early Tier 1 standards through mechanical optimization.
The cylinder block is a high-strength, deep-skirt cast iron structure
designed for maximum rigidity under extreme loads. It incorporates
replaceable wet-type cylinder liners. The liners are pressed into the
block and sealed at the top with a copper gasket under a
precision-machined flange. The lower end employs a cross-bolted main
bearing design.
Each of the seven main bearing caps is secured by two vertical bolts and
two horizontal cross bolts that thread into the block's lower skirt.
This configuration creates an immensely rigid foundation for the
crankshaft, essential for managing the high cylinder pressures of the
DITA configuration. The camshaft is gear-driven and rotates within
bearings machined directly into the block.
A single cast iron cylinder head is used, secured by four bolts per
cylinder. The combustion chamber design is a direct injection type. The
head employs two valves per cylinder - one intake and one exhaust. Valve
seat inserts are hardened for extended durability under high thermal
loads. Valve guides are replaceable.
Valve actuation is via pushrods and rocker arms; the rocker arms are
shaft-mounted. Valve lash is adjusted manually using a screw and locknut
on each rocker arm. The cylinder head gasket is a solid copper or
composite design, selected for its ability to seal high combustion
pressures and temperatures.
The engine utilizes a direct injection, mechanically controlled fuel
system. It employs individual camshaft-driven injection pumps, one for
each cylinder. These inline plunger-type pumps generate high pressure
and deliver fuel to multi-hole injectors mounted in the cylinder head.
Injection timing is adjustable.
A gear-type transfer pump supplies fuel from the tank to the injection
pumps. The fuel circuit includes a primary filter/water separator and a
secondary spin-on fuel filter. This system is mechanically precise,
robust, and capable of sustaining the high injection pressures required
for efficient direct injection combustion with aftercooled air.
Lubrication is provided by a gear-type oil pump driven from the front
gear train. Oil is drawn from a deep, cast iron or fabricated steel sump
through a pickup tube and screen. It is then forced through a full-flow,
spin-on or canister-type oil filter. A bypass valve protects the system.
Filtered oil is routed through an oil cooler before entering the main
oil gallery. From the gallery, oil is distributed to the crankshaft main
and connecting rod bearings, camshaft bearings, turbocharger, and valve
train. Piston cooling jets spray a continuous stream of oil onto the
underside of each piston, a critical feature for managing piston
temperature in this high-output engine.
Coolant circulation is managed by a gear-driven centrifugal water pump.
Coolant flows from the pump through passages in the cylinder block and
cylinder head. A wax-pellet thermostat regulates engine operating
temperature. The defining feature of the DITA configuration is the
air-to-air aftercooler (ATAAC).
This is a separate heat exchanger, mounted in the intake air circuit
after the turbocharger. Ambient air is used to cool the compressed
intake charge, significantly increasing its density before it enters the
cylinders. The engine cooling system itself requires a radiator or heat
exchanger of substantial capacity to handle the total heat rejection.
Starting System: 12-volt, 24-volt, or 32-volt electric starting motor,
with air starting as a common option for industrial and mining
applications. Charging System: A heavy-duty brushless alternator, with
output from 65 to 130 amperes depending on application requirements.
Air Intake System: A dry-type, often two-stage air cleaner system with a
service indicator. Air flows through the cleaner, into the turbocharger
compressor, through the air-to-air aftercooler core, and into the intake
manifold. Exhaust System: A cast iron exhaust manifold routes gases to
the turbocharger turbine inlet. A wastegate is used to control boost
pressure.
Dimensions are application-dependent but reflect a large displacement
inline-six engine. For a standard industrial configuration, approximate
length is 1780 mm (70.1 inches), width is 940 mm (37.0 inches), and
height is 1350 mm (53.1 inches). The substantial stroke contributes to
the engine's overall height and length. The net dry engine weight,
excluding fluids but including standard accessories like alternator and
air compressor, is approximately 895 kg (1973 pounds). This weight is
indicative of the engine's heavy-duty construction components.
Engine Oil Grade: Use Caterpillar Diesel Engine Oil (DEO) or an
equivalent oil meeting API CD, CE, or CF-4 specifications. SAE 15W-40 is
standard for general operation. Oil Change Interval: Determined by
service severity. In severe mining or construction duty, intervals of
250 hours are standard. Less severe applications may extend to 500
hours. Oil analysis is a recommended practice.
Oil System Capacity: Total refill capacity, including filter change, is
34.0 Liters (9.0 US gallons). Cooling System Capacity: Total cooling
system capacity, including radiator and aftercooler circuit, is
approximately 68.0 Liters (18.0 US gallons).
Fuel Filter: Replace primary and secondary fuel filter elements every
500 hours or as indicated by service conditions. Air Filter: Service or
replace based on restriction gauge indication. Operation in high-dust
environments requires daily checks and frequent servicing. 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
demineralized water. Maintain proper concentration of supplemental
coolant additive (SCA) at all times to prevent wet liner cavitation, a
critical requirement for this engine.
Cylinder Head Bolts: Tighten in a specific three-step sequence. Final
torque: 270 Nm (200 lb-ft).
Main Bearing Cap Bolts (Vertical): 340 Nm (250 lb-ft).
Main Bearing Cap Cross Bolts: 160 Nm (118 lb-ft).
Connecting Rod Cap Bolts: 200 Nm (148 lb-ft) plus an additional
60-degree turn.
Flywheel Housing-to-Block Bolts: 160 Nm (118 lb-ft).
Flywheel-to-Crankshaft Bolts: 230 Nm (170 lb-ft).
Injector Clamp Bolt: 50 Nm (37 lb-ft).
Oil Pan Bolts: 55 Nm (41 lb-ft).
Oil Filter Cap or Cartridge: For spin-on filters, hand-tighten plus
three-quarters turn. For canister types, tighten cap to 75 Nm (55
lb-ft).
The Caterpillar 3306 DITA engine was a
cornerstone in heavy industries:
Mining: Primary power for underground loaders (LHDs), drill rigs, and
smaller haul trucks. Heavy Construction: Found in Caterpillar 977, 983
Track Loaders; 613, 623 Wheel Tractor-Scrapers; 824, 834 Wheel Dozers;
and large hydraulic excavators. Power Generation: A prime mover for
large stationary generator sets in the 200-350 kW range for prime and
standby power.
Oil and Gas: Powered large mud pumps, cement pumps, and frac units in
well service applications. Marine: Used in larger commercial workboats,
tugboats, and fishing vessels as a propulsion and auxiliary engine.
Locomotives: Served as the engine in industrial and small switching
locomotives. Forestry: Powered large skidders and forwarders in logging
operations.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
