Mercedes-Benz M157 Specifications
| Engine Model: Mercedes-Benz M157 |
| Engine Type: 4-cycle 8-cylinder DOHC 32-valve turbocharged liquid-cooled gasoline |
| Total Displacement: 333.3 cu.in (5.46 L) |
| Rated Engine Power: 518-577 Hp (386-430 kW) at 6250 rpm |
| Fuel System Type: Gasoline direct injection |
____________________________________________________________________________________
The Mercedes-Benz M157 is a high-performance,
twin-turbocharged V8 engine produced by Mercedes-AMG between 2011 and 2018.
Developed as the forced-induction successor to the naturally aspirated 6.2-liter
M156, the M157 represented AMG’s strategic shift toward downsized displacement
combined with forced induction to deliver increased low-end torque while
reducing fuel consumption. Based on the standard Mercedes-Benz M278 V8
architecture, the M157 incorporates AMG-specific heavy-duty internals, increased
displacement, and a higher output calibration.
The engine features a 90-degree V8 configuration with aluminum alloy
construction, direct fuel injection, and a pair of Garrett Honeywell
turbochargers mounted within the engine’s V-valley. Each unit is hand-assembled
according to the “One Man, One Engine” philosophy, with final assembly and
certification performed by a single AMG master technician.
Engine Type: 90° V8, 4-cycle, water-cooled, twin-turbocharged gasoline.
Displacement: 5,461 cc (333.3 cu.in).
Bore: 98.0 mm (3.86 in).
Stroke: 90.5 mm (3.56 in).
Compression Ratio: 10.0:1.
Firing Order: 1-5-4-8-6-3-7-2.
Boost Pressure: 1.0 bar (14.5 psi) for standard variants.
Boost Pressure: 1.3 bar (18.9 psi) for S-Model variants.
Maximum Power
Standard variants: 518-536 hp (386-400 kW) @ 5,500-6,250 rpm.
S-Model variants: 550-577 hp (410-430 kW) @ 5,500-6,250 rpm.
Maximum Torque
Standard variants: 700-800 Nm (516-590 lb-ft) @ 1,700-5,000 rpm.
S-Model variants: 800-900 Nm (590-664 lb-ft) @ 2,500-4,500 rpm.
Valvetrain Configuration: Dual Overhead Camshaft (DOHC) per cylinder bank,
operating 32 valves (4 valves per cylinder). The valvetrain incorporates
continuously variable camshaft timing on both intake and exhaust camshafts.
Camshafts are hollow-cast for reduced mass.0
The cylinder block is manufactured from aluminum alloy
with Silitec cylinder liners. Silitec is a high-silicon aluminum alloy applied
as a linerless coating using a spray-on process, providing wear resistance
comparable to cast iron while reducing friction and mass. Bore diameter measures
98.0 mm (3.86 in). The block features a closed-deck design with reinforced
bulkheads to withstand combustion pressures exceeding 120 bar (1,740 psi) under
full-load operation.
The 90-degree V-angle provides inherent balance characteristics while
accommodating the twin turbochargers positioned within the V-valley. The
crankshaft is forged steel with eight counterweights, supported by five main
bearings. The bedplate design incorporates a cast aluminum lower crankcase that
integrates main bearing caps into a single structural component.
Each cylinder head is manufactured from aluminum alloy
with cross-flow port architecture and a pent-roof combustion chamber design
optimized for direct injection and forced induction.
Valves: 32 total; 16 intake, 16 exhaust.
Intake Valve Diameter: 35.0 mm (1.38 in).
Exhaust Valve Diameter: 30.0 mm (1.18 in).
Valve Stem Diameter: 5.0 mm (0.20 in) for both intake and exhaust, utilizing
low-friction stem seals.
Valve Seat Inserts: Sintered alloy with multi-angle seat geometry (three-angle
intake, three-angle exhaust) designed for high thermal conductivity under forced
induction.
Valve Guides: Press-fit sintered iron guides.
Hydraulic Lash Adjusters: Direct-acting units mounted in the cylinder head
casting, operating on bucket-type cam followers.
Camshafts: Hollow-cast steel camshafts with assembled lobes to reduce rotational
inertia. Continuously variable camshaft timing (CAMTRONIC) provides adjustment
ranges of 40 degrees on the intake camshafts and 38 degrees on the exhaust
camshafts.
Valve Springs: High-tension springs with beehive geometry to manage valve train
dynamics at elevated engine speeds. Combustion Chamber: Piston crowns feature a
recessed bowl design that directs fuel spray toward the centrally mounted spark
plug while minimizing wall wetting.
The fuel system employs third-generation direct
injection with piezoelectric injectors. Injection Type: Direct injection into
the combustion chamber with injectors mounted centrally between the intake and
exhaust valves. Injector Configuration: Piezoelectric injectors with multi-hole
nozzles enabling up to five injection events per combustion cycle.
Fuel Pressure: Low-pressure circuit supplies fuel from the in-tank pump at
3.5-4.5 bar (51-65 psi). A high-pressure mechanical pump driven by the intake
camshaft of the right bank elevates pressure to a maximum of 200 bar (2,900
psi). High-Pressure Pump: Single-piston plunger pump with a fuel metering valve
controlling rail pressure based on engine load and speed. Engine Management
System: Bosch MED 17.7.3 ECU with wideband oxygen sensors per bank and
individual cylinder knock control.
The lubrication system is a full-flow, pressurized
design utilizing a variable displacement oil pump integrated into the engine
front cover. Oil Pump Type: Variable displacement vane-type pump driven by the
crankshaft. Pump displacement is regulated by the engine control unit based on
engine speed, load, and oil temperature.
Oil Capacity: 8.5-9.5 liters (9.0-10.0 qt) including oil filter replacement.
Capacity varies with the presence of the external oil cooler system. Recommended
Oil Viscosity: 0W-40 or 5W-40. Oil Quality Requirement: Mercedes-Benz
specification 229.5 (full synthetic, low-ash formulation). ACEA A3/B4 or C3
depending on emissions equipment.
Oil Pressure: At warm idle, pressure ranges from 1.2-1.8 bar (17-26 psi). Under
load, the variable displacement pump maintains pressure between 4.0-5.5 bar
(58-80 psi). Oil Cooler: Liquid-to-oil plate-type heat exchanger integrated into
the oil filter housing, supplemented by an external air-to-oil cooler for
high-performance applications. The external cooler is thermostatically
controlled. Oil Filter: Cartridge-type filter housed within a spin-on or modular
housing accessible from the engine top.
The cooling system is pressurized and utilizes a
primary water pump driven by the accessory belt and a secondary electric water
pump for intercooler and post-shutdown thermal management. Primary Water Pump:
Centrifugal pump with a die-cast aluminum housing and stamped steel impeller.
Secondary Water Pump: Electric auxiliary pump located in the intercooler
circuit, circulating coolant through the air-to-water intercoolers after engine
shutdown to prevent heat soak. Thermostat: Map-controlled thermostat with an
electrically heated expansion element, allowing the engine control unit to vary
opening temperature between 80-105 °C (176-221 °F) based on load and operating
conditions.
Coolant Capacity: 13.0-14.5 liters (13.7-15.3 qt) inclusive of engine block,
radiator, heater core, and intercooler circuits. Radiator: High-capacity
cross-flow aluminum core with plastic end tanks. Cooling fan configuration
consists of dual electric fans with pulse-width modulation (PWM) control. System
Pressure: Radiator cap rated at 1.4 bar (20 psi).
Charge Air Cooling: Air-to-water intercoolers integrated into the intake
manifold within the V-valley. A dedicated low-temperature coolant circuit,
separate from the engine cooling system, circulates coolant through the
intercoolers and a front-mounted radiator.
| Intake and Exhaust Systems |
Exhaust System: Cast stainless steel exhaust manifolds
integrated with the turbocharger housings. A dual exhaust system with primary
catalytic converters mounted immediately downstream of each turbocharger,
followed by secondary catalysts and a valved muffler system that modulates
backpressure and sound output.
Intake Manifold: Composite plastic manifold with integrated air-to-water
intercoolers mounted directly above the cylinder heads. The manifold
incorporates swirl flaps that vary intake port geometry based on engine load.
Direct ignition system with individual pencil-type
ignition coils mounted directly over each spark plug (coil-on-plug). Coils are
controlled by the engine control unit with integrated ion-sensing capability for
misfire detection and knock control.
Spark Plug Type: NGK IFR9G-K or equivalent.
Spark Plug Gap: 0.7-0.8 mm (0.028-0.031 in).
Two Garrett Honeywell turbochargers (model GT15 or GT17
depending on production date) mounted within the V-valley between the cylinder
banks. Each turbocharger features a titanium-aluminide turbine wheel for reduced
inertia and a water-cooled bearing housing. Wastegate actuation is electronic,
controlled by the engine control unit.
Timing System: Maintenance-free timing chain system
with two primary chains and two secondary chains. A primary chain drives the
intake camshaft of each bank from the crankshaft. Secondary chains transmit
drive from the intake camshaft to the exhaust camshaft on each bank. Hydraulic
chain tensioners supplied by the engine lubrication circuit maintain tension.
Tensioner check valves prevent startup rattle.
Crankcase Ventilation: Closed-loop system with an integrated oil separator
(cyclonic and baffle combination) incorporated into the valve covers. Blow-by
gases are routed to the turbocharger compressor inlets.
Start-Stop System: Controlled Efficiency (C) mode incorporates engine stop-start
functionality with a reinforced starter motor and a secondary battery management
system.
Overall Length: 780 mm (30.7 in) measured from
accessory drive pulley face to transmission mounting flange.
Overall Width: 860 mm (33.9 in) inclusive of turbocharger assemblies, intake
manifold, and exhaust components.
Overall Height: 750 mm (29.5 in) from oil pan bottom surface to valve cover top
surface.
Dry Weight: 201-208 kg (443-459 lb) depending on turbocharger configuration and
accessory drive components.
Timing Chain Inspection Interval: Chain, tensioners,
and guides inspection recommended at 120,000 km (75,000 miles). Replacement is
condition-based. Early production models may require tensioner check valve
inspection for cold-start noise. Spark Plug Replacement Interval: 48,000 km
(30,000 miles) due to high cylinder pressures and forced induction operating
conditions.
Drive Belt Tension (Accessory): Automatic tensioner maintains correct tension;
no manual adjustment required. Belt replacement interval is 80,000 km (50,000
miles). Coolant Change Interval: 120,000 km (75,000 miles) or 5 years. Engine
Oil Change Interval: 10,000 km (6,200 miles) or 12 months, whichever occurs
first. Severe service interval: 5,000 km (3,100 miles). Idle Speed (warm,
neutral): 600-650 rpm. Injection Timing: Electronically controlled with
closed-loop feedback from wideband oxygen sensors and knock detection.
Cylinder Head Bolts (cold): 40 Nm (30 lb-ft).
Crankshaft Damper Pulley Bolt: 200-220 Nm (148-162 lb-ft) plus 90° rotation.
Connecting Rod Cap Bolts: 30 Nm (22 lb-ft) plus 90° rotation.
Main Bearing Cap Bolts (bedplate-to-block): 50 Nm (37 lb-ft).
Camshaft Bearing Cap Bolts: 10-12 Nm (7-9 lb-ft).
Camshaft Sprocket Bolts: 80-90 Nm (59-66 lb-ft).
Valve Cover Bolts: 9-11 Nm (7-8 lb-ft).
Intake Manifold Bolts: 20-25 Nm (15-18 lb-ft).
Exhaust Manifold Nuts (turbocharger to cylinder head): 45-50 Nm (33-37 lb-ft).
Turbocharger Mounting Bolts: 40-45 Nm (30-33 lb-ft).
Oil Pan Bolts: 10-12 Nm (7-9 lb-ft).
Timing Chain Tensioner Bolts: 40-45 Nm (30-33 lb-ft).
Timing Chain Guide Bolts: 20-25 Nm (15-18 lb-ft).
Water Pump Bolts: 20-25 Nm (15-18 lb-ft).
High-Pressure Fuel Pump Mounting Bolts: 20-25 Nm (15-18 lb-ft).
Fuel Injector Clamp Bolts: 25-30 Nm (18-22 lb-ft).
Flywheel / Drive Plate Bolts: 120-130 Nm (89-96 lb-ft) plus 90° rotation.
Engine Mount Bracket Bolts: 55-65 Nm (41-48 lb-ft).
Mercedes-Benz S63 AMG (W221, W222): 2011-2017 model
years. The M157 served as the flagship powertrain for the S-Class AMG variant
across two generations, with the W222 receiving updated calibration for
increased power output.
Mercedes-Benz CL63 AMG (C216): 2011-2014. The M157 replaced the naturally
aspirated M156 in the CL-Class coupe.
Mercedes-Benz E63 AMG (W212): 2011-2016. The M157 was offered in both
rear-wheel-drive and 4MATIC all-wheel-drive configurations, with the Performance
Package available in the E63 S variant.
Mercedes-Benz CLS63 AMG (C218): 2011-2018. The M157 powered the CLS-Class
four-door coupe AMG variant, with Shooting Brake configurations in European
markets receiving the same powertrain.
Mercedes-Benz ML63 AMG / GLE63 AMG (W166): 2012-2018. The M157 was installed in
the mid-size SUV AMG variant, receiving model-specific calibration for torque
delivery and cooling.
Mercedes-Benz GL63 AMG / GLS63 AMG (X166): 2012-2018. The M157 powered the
full-size SUV AMG variant, with additional cooling system capacity for towing
and high-load applications.
Mercedes-Benz G63 AMG (W463): 2012-2018. The M157 was introduced as the
powertrain for the G-Class AMG variant, featuring revised engine mounts and a
reinforced cooling system for off-road operation.
Mercedes-Benz SL63 AMG (R231): 2012-2019. The M157 was utilized in the roadster
AMG variant, with the S-Model designation appearing in later production years.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
