Cat C27 ACERT Specifications
| Engine Model: Caterpillar C27 ACERT |
| Engine Type: 4-stroke 12-cylinder V-block turbocharged liquid-cooled diesel |
| Total Displacement: 1649 cu.in (27.0 L) |
| Rated Engine Power: 800-1050 Hp (597-783 kW) at 2100 rpm |
| Fuel System Type: Unit Injection |
____________________________________________________________________________________
The Caterpillar C27 ACERT is a 27.0-liter,
12-cylinder, 65° V-configuration diesel engine engineered for heavy-duty
industrial, mining, marine, and construction applications. As a member
of Caterpillar’s ACERT (Advanced Combustion Emissions Reduction
Technology) family, this engine represents a convergence of robust
mechanical architecture and sophisticated electronic control. The design
focuses on delivering high power density while managing emissions
through technologies like the ADEM A4 Electronic Control Module and, in
its Tier 4 Final configuration, a combination of Diesel Oxidation
Catalyst and Selective Catalytic Reduction.
The C27 ACERT is distinguished by its use of the MEUI (Mechanical
Actuated Electronically Controlled Unit Injection) fuel system, which
provides the high injection pressures necessary for combustion
efficiency and performance optimization across a wide operating range.
Built with a deep-skirt cylinder block and a four-valve cylinder head
design, the engine prioritizes structural rigidity and thermal
management, making it suitable for continuous duty in demanding
environments such as large off-highway trucks, dozers, and marine
vessels.
The engine operates on a four-stroke cycle with a 65° V-angle between
the cylinder banks. Total displacement is 27.0 Liters (1,649 cu.in),
derived from a bore of 137 mm (5.4 in) and a stroke of 152 mm (6.0 in).
The aspiration system is configured as Turbocharged-Aftercooled (TA) for
most industrial ratings, with Series Turbocharged (TTA) configurations
available for specific high-altitude or high-power applications.
Combustion is achieved through direct injection, utilizing a compression
ratio of 16.5:1. When viewed from the flywheel end, the standard
direction of rotation is counterclockwise. The firing order is
1-4-9-8-5-2-11-10-3-6-7-12, a sequence designed to balance the forces
within the V12 configuration and minimize torsional vibration.
Performance data is segmented by application and emissions
certification. The power range spans from 597 kW to 783 kW (800 hp to
1,050 hp), with the rated speed window falling between 1800 RPM and 2100
RPM, depending on the specific configuration for industrial, mining, or
marine use. Peak power is achieved at 1800 RPM. The engine develops
maximum torque between 4,660 Nm and 5,250 Nm (3,437 lb-ft to 3,872
lb-ft) within a speed band of 1200 to 1500 RPM, providing substantial
lugging capability for traction-driven applications.
The cylinder block is a deep-skirt, high-strength cast-iron design,
which enhances overall rigidity and reduces noise, vibration, and
harshness. The deep-skirt construction extends the cylinder walls below
the crankshaft centerline, providing increased support for the main
bearing caps. This design minimizes bore distortion under high cylinder
pressures, contributing to improved piston ring sealing and longer
component life.
The block incorporates water jackets for efficient cooling around the
cylinders and includes integrated oil galleries that supply pressurized
lubricant to the crankshaft bearings, connecting rods, and piston
cooling jets. The block is machined to accommodate wet-type cylinder
liners, which are replaceable and allow for a more robust thermal
transfer path between the liner and the coolant.
The engine utilizes individual cylinder heads for each cylinder bank,
constructed from high-grade cast iron. Each cylinder head is a
cross-flow design that separates the intake and exhaust passages to
optimize volumetric efficiency and cooling. The valve train consists of
four valves per cylinder - two intake and two exhaust - actuated by a
single overhead camshaft per bank.
This four-valve configuration centralizes the fuel injector, promoting
optimal fuel-air mixing and combustion efficiency. The valve stems are
chrome-plated for wear resistance, and the valve seats are constructed
from hardened materials to withstand the thermal and mechanical stresses
of high-output operation. Valve bridges ensure synchronized actuation of
the paired valves, maintaining precise valve lash and seating integrity.
The fuel system is the MEUI (Mechanical Actuated Electronically
Controlled Unit Injection). This system combines the high-pressure
mechanical actuation of unit injectors with precise electronic control
over injection timing and duration. Each cylinder has its own unit
injector, which is actuated by the engine camshaft, generating injection
pressures sufficient for complete combustion. The ADEM A4 Electronic
Control Module governs the injector solenoids, allowing for variable
injection timing and rate shaping to optimize performance, fuel economy,
and emissions.
The system operates without a high-pressure common rail; instead, a
low-pressure fuel transfer pump supplies fuel to the injectors, with
excess fuel circulating for cooling. For Tier 4 Final emissions
compliance, this system is paired with aftertreatment components,
including a Diesel Oxidation Catalyst (DOC) and a Selective Catalytic
Reduction (SCR) system to reduce particulate matter and oxides of
nitrogen.
The lubrication system is a forced-feed, full-flow filtration design. A
gear-driven, positive displacement oil pump draws lubricant from the
sump and routes it through an oil cooler and a full-flow oil filter
before distribution to critical engine components. The system
incorporates piston cooling jets that direct oil streams to the
underside of the pistons, managing piston temperature under high thermal
loads.
Total oil system capacity varies based on the configuration of the oil
pan, with a range of 68.0 to 95.0 Liters (18.0 to 25.0 U.S. gal). A
spin-on or cartridge-type oil filter with a bypass valve ensures
continuous lubrication even if the filter becomes restricted.
The cooling system is a pressurized, liquid-cooled design utilizing a
centrifugal water pump. The pump circulates coolant through the cylinder
block, cylinder heads, and the aftercooler (for charge air cooling). The
system is designed to maintain consistent operating temperatures under
high load conditions, with coolant capacity for the engine alone 55
Liters (14.5 U.S. gal).
A thermostatically controlled bypass system regulates coolant flow to
maintain optimal operating temperature, reducing thermal stress and
ensuring efficient combustion. The coolant also circulates through the
turbocharger and, in some configurations, through the emissions
aftertreatment components for thermal management.
| Intake and Exhaust Systems |
The intake system features a turbocharger (single or series) coupled
with a jacket-water aftercooler (JWAC) or air-to-air aftercooler
(ATAAC), depending on the application, to reduce intake air temperature
and increase air density for combustion.
The exhaust system incorporates the aftertreatment components for Tier 4
Final variants, with sensors for NOx, particulate matter, and exhaust
gas temperature.
The electrical system operates on a 24-volt architecture, utilizing a
heavy-duty alternator and starter motor designed for high-cranking
torque. The ADEM A4 Electronic Control Module serves as the central
processing unit, monitoring inputs from sensors such as intake manifold
pressure, coolant temperature, and crankcase pressure. The ECM manages
fuel delivery, emissions controls, and engine protection functions,
including derate strategies for critical faults.
The overall length is 1,917 mm (75.5 in), the width is 1,464 mm (57.6
in), and the height is 1,319 mm (51.9 in). Dry weight, which excludes
fluids such as oil, coolant, and fuel, falls within a range of 2,800 kg
to 3,000 kg (6,173 lb to 6,614 lb). This weight contributes to the
machine’s overall stability and durability in applications such as
off-highway trucks and large dozers.
For the cylinder head bolts, the procedure is multi-stage: an initial
torque of 150 Nm (110 lb-ft) is applied, followed by a second pass to
150 Nm (110 lb-ft), and concluded with a 90° turn to achieve the proper
clamp load on the cylinder head gasket.
The connecting rod bolts are torqued to 90 Nm (66 lb-ft), followed by a
90° angular turn. This method ensures the bolts are stretched within
their elastic limit to accommodate the high tensile loads during engine
operation.
The main bearing caps are secured with bolts torqued to 260 Nm (190
lb-ft), followed by an additional 120° turn. This specification is
critical for maintaining crankshaft alignment and bearing clearance
under the high compressive forces generated by the engine.
The Caterpillar C27 ACERT engine is utilized across a broad spectrum of
heavy machinery and vehicles.
In mining, it serves as the primary power unit for the Cat 773G and 775G
Off-Highway Trucks, where its torque curve and power output are matched
to haul road conditions and payload capacities.
For construction, the engine is installed in the Cat D10T2 Dozer,
providing the drawbar pull required for ripping and dozing applications,
as well as in the 990K Wheel Loader, where its power is utilized for
high-capacity excavation and material handling.
In industrial sectors, the C27 ACERT powers large hydraulic power units
for demolition shears and material processors, as well as rock crushers
and dredge pumps that demand continuous high horsepower and torque under
variable loads.
For marine applications, the engine is rated for high-speed commercial
vessels and yachts, offering the power-to-weight ratio and reliability
required for propulsion in demanding marine environments.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
