Mercedes-Benz M159 Specifications
| Engine Model: Mercedes-Benz M159 |
| Engine Type: 4-cycle 8-cylinder DOHC 32-valve liquid-cooled gasoline |
| Total Displacement: 378.8 cu.in (6.21 L) |
| Rated Engine Power: 622 Hp (463 kW) at 6800 rpm |
| Fuel System Type: Sequential multi-point electronic fuel injection |
____________________________________________________________________________________
The Mercedes-Benz M159 engine is a
high-revving, naturally aspirated V8 powerplant developed by
Mercedes-AMG as the ultimate evolution of its front-mid-engine,
rear-wheel-drive performance architecture. It is a thoroughbred
racing-derived unit, building directly upon the legacy of the M156
engine but with extensive modifications for maximum performance,
response, and durability in an extreme application.
Designed and hand-built in Affalterbach, the M159 features a dry-sump
lubrication system, individual throttle bodies, forged internals, and a
high-compression ratio. Its sole purpose was to power the Mercedes-Benz
SLS AMG, serving as the heart of this gullwing-door supercar. The engine
is celebrated for its linear power delivery, immediate throttle
response, and distinctive auditory character, embodying the peak of
AMG's naturally aspirated V8 philosophy before the widespread adoption
of forced induction.
Engine family: Mercedes-Benz M159.
Engine type: 90-degree V8, four-stroke Otto cycle, naturally aspirated.
Displacement: 6208 cc (378.8 cubic inches).
Bore: 102.2 mm (4.024 inches).
Stroke: 94.6 mm (3.724 inches).
Compression ratio: 11.3:1.
Maximum power output: 622 Hp (463 kW) at 6800 rpm.
Maximum torque output: 468 lb-ft (635 Nm) at 4750 rpm.
Redline: 7200 rpm. Firing order: 1-5-4-8-6-3-7-2.
Engine orientation: Longitudinal, front-mid mounted.
Aspiration: Naturally aspirated with individual throttle bodies.
Fuel type: Premium unleaded gasoline (98 RON recommended).
Recommended oil grade: SAE 0W-40, meeting Mercedes-Benz specification
229.5.
Oil capacity: 11.0 liters (11.6 U.S. quarts) for the dry-sump system.
Coolant capacity: 15.5 liters (16.4 U.S. quarts).
The cylinder block is a high-strength cast aluminum alloy (AlSi17Cu4Mg)
with silicon-rich liners applied via a patented low-pressure die-casting
process. This creates a wear-resistant running surface for the pistons
directly within the aluminum block, eliminating separate cylinder liners
and improving heat transfer. The block is reinforced with a closed-deck
design at the cylinder level, providing immense rigidity to withstand
high combustion pressures and rotational forces. The crankshaft is a
forged steel unit with a stroke of 94.6 mm (3.724 inches). It is a
cross-plane crankshaft with five main bearings.
Main bearing caps are made from a high-strength aluminum alloy and are
secured with four bolts each: two vertical and two lateral cross-bolts.
Connecting rods are forged from premium micro-alloyed steel. Pistons are
forged aluminum alloy, designed with a specific contour to achieve the
11.3:1 compression ratio. They are fitted with two low-tension,
low-friction compression rings and one oil control ring. Each piston is
cooled by dedicated oil spray jets.
Each cylinder bank is fitted with a sand-cast, high-flow aluminum alloy
cylinder head. The valve train employs dual overhead camshafts (DOHC)
per bank, driven by a dual-stage chain drive system from the crankshaft.
Camshaft adjustment is continuous on both the intake and exhaust sides,
facilitated by hydraulic vane-type adjusters. This allows for a wide
range of valve timing optimization.
Valve actuation is via bucket-type tappets, requiring manual valve
clearance adjustment. The engine uses four valves per cylinder (two
intake, two exhaust). Intake valves are 35.0 mm (1.378 inches) in
diameter, while exhaust valves are 30.0 mm (1.181 inches) in diameter.
Valve stems are 6.0 mm (0.236 inches) in diameter. Intake and exhaust
ports are optimized for high volumetric efficiency and flow. Valve
springs are designed for stable operation up to the 7200 rpm redline.
The fuel system is a high-performance sequential multi-port injection
setup controlled by a Bosch MED 17.7 engine control unit. Its defining
feature is the use of eight individual, electronically controlled
throttle bodies, one for each cylinder. This design eliminates a common
intake plenum and provides instantaneous, precise air metering for
optimal throttle response.
Fuel is supplied by two high-pressure electric fuel pumps located in the
fuel tank. Fuel rail pressure is maintained at a constant 3.8 bar (55
psi) by a regulator. The injectors are positioned for optimal spray
pattern into the intake ports. The engine management system incorporates
multiple sensors, including two knock sensors per cylinder bank, for
precise control of ignition timing and fuel injection under all
conditions.
The lubrication system is a mandatory dry-sump design. This
configuration employs a separate external oil tank and multiple scavenge
pumps to remove oil from the engine sump, ensuring a consistent oil
supply to the pump's pressure stage during high lateral and longitudinal
acceleration. The system uses a total of six pumps: one pressure pump
and five scavenge pumps.
The oil tank is integrated into the engine's structural casting at the
front. This dry-sump design allows the engine to be mounted lower in the
chassis, lowering the center of gravity. It also prevents oil starvation
during extreme cornering. Oil is cooled by a large, front-mounted oil
cooler with integrated thermostat. The filter is a remote-mounted
cartridge type. Oil temperature and pressure are constantly monitored.
The cooling system is a high-capacity, pressurized forced-circulation
system. It features a dual-circuit design for the cylinder heads and
cylinder block to optimize temperature distribution. An electronically
controlled map thermostat governs coolant flow. The main radiator is a
high-efficiency aluminum unit. A separate, dedicated heat exchanger
cools the engine oil. An electric auxiliary pump can continue coolant
circulation after engine shutdown to manage heat soak.
The ignition system is a coil-on-plug design, with one individual
ignition coil per cylinder mounted directly on the spark plug. The
exhaust system features tuned, equal-length stainless steel headers that
merge into a dual-path system with active butterfly valves to modulate
backpressure and sound. A start-stop system is not used due to the
performance nature of the application.
The external dimensions of the M159 engine are compact considering its
displacement and output, a result of the dry-sump design which reduces
overall height. Approximate length is 750 mm (29.53 inches). Approximate
width is 800 mm (31.50 inches). Approximate height is 650 mm (25.59
inches). These dimensions include essential ancillaries but exclude the
exhaust manifolds. The weight of the complete M159 engine, including all
fluids, the dry-sump tank, and attached accessories, is 206 kg (454
lbs). This low weight contributes to the favorable front-rear weight
distribution of the vehicle.
Engine oil and filter change intervals are dictated by the vehicle's
Flexible Service System (FSS), but for severe use, annual or 10,000 mile
(16,000 kilometer) intervals are recommended. The dry-sump system
requires precise oil level checking procedures with the engine at
operating temperature. Spark plug replacement interval is 60,000 miles
(96,000 km) or 4 years. Valve clearance inspection and adjustment is a
critical service item, required every 37,500 miles (60,000 km).
The timing chain system is designed for longevity and does not have a
scheduled replacement, but inspection during major service is prudent.
Coolant replacement is recommended every 15 years or 150,000 miles
(240,000 km). Air filters should be inspected every 30,000 miles (48,000
km). The accessory drive belt should be inspected every 20,000 miles
(32,000 km).
All torque specifications are for clean, lightly oiled threads unless
noted otherwise. Cylinder head bolts are tightened in a multi-stage
angular procedure: first stage 50 Nm (37 lb-ft), second stage an
additional 90 degrees, final stage a further 90 degrees. Main bearing
cap bolts (vertical): 50 Nm (37 lb-ft) plus 90 degrees. Main bearing cap
cross-bolts: 50 Nm (37 lb-ft).
Connecting rod cap bolts: 30 Nm (22 lb-ft) plus 90 degrees. Crankshaft
central bolt: 250 Nm (184 lb-ft) plus 90 degrees. Camshaft sprocket
bolts: 100 Nm (74 lb-ft). Spark plugs: 25 Nm (18 lb-ft). Individual
throttle body mounting fasteners: 10 Nm (7.4 lb-ft). Oil drain plug for
the dry-sump tank: 40 Nm (30 lb-ft).
The Mercedes-Benz M159 engine had a single, exclusive vehicle
application. It was developed specifically for and installed solely in
the Mercedes-Benz SLS AMG (C197 chassis for the coupe, R197 for the
roadster). This encompassed all standard SLS AMG variants from its
launch in 2010 until the end of production in 2014.
The engine was not used in any other Mercedes-Benz or AMG model, making
it a unique and purpose-built power unit. Its successor in the AMG GT
model line, the M178, adopted a hot-V twin-turbocharged configuration.
The M159 remains the definitive and most powerful naturally aspirated V8
engine ever produced by Mercedes-AMG for a production road car.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
