Most Powerful 4-Cylinder Engine, Mercedes-AMG's M139

[Franco Cozzo]

The turbocharged four-cylinder is available in two power output versions, able to produce 387 hp (285kW) and 421 hp (310 kW), respectively. The first powers “standard” AMG models while the second, which is the most powerful inline-four engine in production, is used for the top-shelf S versions.

It has been developed to be extremely agile and responsive and the designers carefully balanced the torque curve to achieve a power delivery similar to that of a naturally aspired engine.
The countless hours of hard work resulted in a peak torque of 500 Nm (369 ft-lb) for the S version and 480 Nm (354 ft-lb) for the basic model, which is available around 5000 rpm, while the engine’s maximum speed has been improved to 7200 rpm. This gives the small two-liter unit the agility and feel of a high-revving performance engine.

It has many improvements and innovative design features, like the new twin-scroll turbocharger that is extremely responsive at low engine speeds and provides a healthy dose of boost in the higher rpm range.

To achieve this, the turbine housing is divided into two flow passages that run parallel to each other while also receiving help from divided ducts in the exhaust manifold.

Additionally, roller bearings are fitted to the shafts of the compressor and turbine, an innovation that is borrowed from its famous AMG 4.0-liter V8 sibling. These bearings help minimize mechanical friction within the turbocharger.

To reduce friction between the pistons and cylinders, engineers opted to coat the linings using the patented NANOSLIDE technology that was pioneered on the Mercedes AMG Petronas Formula 1 engine.

Compared to its predecessor, the AMG M133, the new engine has larger exhaust valves that were made possible by repositioning and slightly angling the injection nozzles and spark plug system in the cylinder head.

https://www.autoevolution.com/news/a...39-150959.html

https://www.mercedes-amg.com/en/pres...tion/m139.html

She's got nothin' on the Toyota 1VD-FTV

[boss351290]

If it’s extremely responsive it should make its maximum torque at 2500 rpm not 5000 rpm

Das Gud Ze Gurmains Rok Ya

I'd smash it with my V6 Diesel !

[happy1]

Hi,

You wonder about the durability and cost of ownership. AMG is known for some extremely expensive parts. I wonder how much does a long-block for an M139 cost over the spares counter here in Australia? I would be surprised if it is less than AUD 40k.

When it comes to performance, throwing a whopping 2.1 bar of boost on a 2-litre engine isn't exactly first time it has been done for motorsports applications or by aftermarket tuners, but it isn't often it is done for mass produced consumer cars.

Motorsports applications from the 80s and 90s, such as Lancia, Peugeot, Renault and Ford were applying 1.6 bar to 2 bar of boost already back then.
Here is a snippet about Ford RS200:


Engine

• Longitudinally-mounted, mid-engine, four-wheel-drive layout
• Head/block aluminium alloy/aluminium alloy
• 4 cylinders in line, Nikasil integrated liners
• 5 main bearings. Water cooled, electric fan
• Bore: 86 mm (3.39 in)
• Stroke: 77.6 mm (3.06 in)
• Capacity: 1,803 cc (1.8 L; 110.0 cu in)
• Valve gear: Dual Overhead Cams, 4 valves per cylinder, toothed belt camshaft drive

Compression ratio: 7.2:1. Bosch Motronic engine management system and fuel injection. Garrett T3 turbocharger/boost pressure 23 psi (1.6 bar).

Max. power: 450 PS (331 kW; 444 hp) at 8,000 rpm
Max. torque: 360 lb⋅ft (490 N⋅m) at 5,500 rpm

The accident at Rally Portugal set off a chain reaction and the RS200 became obsolete after only one full year of competition as the FIA, the governing board, which at the time controlled WRC rally racing, abolished Group B after the 1986 season. For 1987, Ford had planned to introduce an "Evolution" variant of the RS200, featuring a development of the BDT engine, called later as BDT-E, displacing 2,137 cc (2.1 L; 130.4 cu in), developed by Briton Brian Hart. Power figures for the engine vary quite a bit from source to source, depending on the mechanical setup e.g. boost levels, power output ranges from as little as 550 hp (558 PS; 410 kW) to as high as 815 hp (826 PS; 608 kW); although most typical output was 580 hp (588 PS; 433 kW) at 8000 rpm and 400 lb⋅ft (542 N⋅m) at 5500 rpm of torque.[2] It has been said that the most powerful Evolution models can accelerate from 0 to 60 mph (97 km/h) in just over two seconds, depending on gearing. Upgraded brakes and suspension components were part of the package as well. The ban on Group B racing effectively forced the E2 model into stillbirth; however, more than a dozen of them were successfully run from August 1986 'til October 1992 in the FIA European Championships for Rallycross Drivers events all over Europe, and Norwegian Martin Schanche claimed the 1991 European rallycross title with a Ford RS200 E2 that produced over 650 bhp (485 kW).
Ford RS200 at the Spirit of Rally 2005

One RS200, which found its way into circuit racing, originated as a road car; it was converted to IMSA GTO specification powered by a 750+ BHP 2.0 litre turbo BDTE Cosworth Evolution engine.

Twin scroll turbochargers isn't exactly new technology either. Subaru STi have had it from about year 2003 onwards.

With a modern direct injected engine such as the Ford Ecoboost 2.3 in the Focus RS, throw a stage III tuning kit on it with the same 2.1 bar of boost, and it will probably also have quite impressive performance.

One thing is for sure; I will not be the owner of an AMG that has expired manufacturer's warranty.

Cheers,

[Vesper Martini]

Only a matter of time for BMW to responds by tweaking the B48 engine which has had 225KW for some time now
The P48 which is the race version already has a whopping 455KW
https://www.thedrive.com/accelerator...ome-since-1969