The one man, one engine method at AMG

On a rare tour of the AMG factory, Neil Vorano sees each engine being built by its own dedicated mechanic.

The AMG mechanics go through sophisticated training to earn the badge, engraved with their signature, that goes on every engine they make. Photos courtesy of AMG
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Everyone appreciates horsepower; the more power under the bonnet, the more fun you get out of a car, right? It's something that appeals to a broad range of drivers; it touches your emotions and senses.

But it takes a special kind of aficionado to find appreciation in the actual source of said horsepower; in the mechanicals, the nuts and bolts, the engineering that goes behind the fun. Perhaps you could call that person a car geek, of sorts.

I guess you could call me that, too. Which is why I'm giddy as I enter the doors of the AMG factory in Affalterbach, Germany, just a short drive outside of Mercedes-Benz's home in Stuttgart. I've been invited to tour the factory of Mercedes's performance division to talk with Alexander Webber, an experienced factory guide, and get a glimpse into the production of these special engines.

"Normally, we only give tours to owners of AMG cars, or people with AMG cars on order; not even owners of normal Mercedes can come," says Webber. On my salary, you could say I check "no" to all of those prerequisites, which makes this tour even more special.

AMG is responsible for warming up regular Mercedes cars into performance-oriented saloons and coupes. But more than just a tuning division, it does so by sharing its engineering expertise and requirements as Mercedes designs its next generation of cars.

"When we develop a new vehicle, we sit down with Mercedes engineers and plan. For example, our engines are always the biggest ones, and if you want to close the hood you need to have the right packaging. So the joint forces at Mercedes and AMG, we decide on engine bay size, we decide on axles, etc. And any time you have the option, you provide an engineering solution for the overall vehicle, or you go for a specific AMG solution. And this is something you can only do when you are part of development."

Though it improves on and modifies standard Mercedes components such as transmissions and suspension systems, the engines are what makes AMG cars stand out. They are completely engineered and built at the Affalterbach plant and are in no way related to any engines produced by Mercedes. And, after the design process - which can take up to four years per engine - it's the production process that makes these powerhouses stand out. AMG follows a "one man, one engine" system, where one single technician builds a single engine from the ground up.

"We have the best mechanics on the planet," Webber says proudly. "It takes a lot to become qualified as an AMG mechanic; they go through a sophisticated training programme and only at the very end are they allowed to work on customer engines. And this is when they get their own metal plate; we won't give that away lighthearted."

The metal plate is on every engine; it holds a signature of the mechanic that assembled the engine. Normally, it takes about three hours for a V8 assembly; the V12s can take up to a whole working day. With about 1,000 employees in total, the plant produces about 20,000 high-performance engines every year.

You might have to change your idea of what an engine factory would be like if you stepped inside AMG's shop. Instead of grease and grime, you're met with white floors and walls. The mechanics are dressed in smart - and clean - black work uniforms, and all are intently focussed on their jobs. There are sporadic noises of power tools and machinery that play a lulling symphony to those who like to turn a spanner themselves.

The engine building process is an 11-step affair; each mechanic starts with the basic block, which is bolted to a wheeled trolley, and they move around a U-shaped work shop, stopping at each station for various jobs.

"If you build by hand, you've got two different ways to build an engine," says Webber. "Like at Ferrari, they have one engine bay where the parts are all brought to it. Here, it's like a supermarket: the mechanics go shopping for parts with the engine from station to station.

If only grocery shopping was this interesting.

But here's the ingenious part of the whole process: being a typical German company, focused on quality and engineering, AMG isn't about to leave everything up to its mechanics, no matter how good they are. Coupled with the hands-on know-how of the skilled technicians, the company has implemented an ingenious computer system to ensure quality standards are met day in and day out.

"Something you will notice is that every part contains a bar code. And every time a mechanic puts on these parts, they scan them into our system, called AMG Trace.

"Every time a mechanic starts building an engine, he downloads the parts list and work instructions and the sequence and the tooling, because we have different versions depending on the vehicle."

The system tracks every single detail surrounding the building of every single engine; even down to the tools used to put it together. As I follow the train around the shop, I stop at a mechanic installing the cylinder heads with a tool that engages every bolt at once. It is calibrated not only to the proper torques, but also the proper sequence of which bolt gets tightened first. All the separate torques are displayed on a computer monitor; if there is a problem, that section goes red, and the problem is dealt with immediately. For anyone with some experience crawling around a car on the dirty floor of a home garage, it's fascinating how precise the whole process is.

"At the end, we know everything about the engine; we know what piston is in what cylinder, and what the connecting rods were torqued to exactly. We even know what tools were used, so if there is a problem we can replace it. The tools won't run unless they are scanned in.

"In fact, we can also run statistics on different tools. If we see after a week or two that the tolerance levels are off, we know we have to adjust that machine. Nothing goes undetected here."

The engines eventually make it around to the end, where they are put through first a pressure test to ensure everything is sealed properly. Then they move to what AMG calls a "cold test": the engines are hooked up to a test bench and rotated as if they are being run.

"The engine is not started, it's propelled by the test bench. And by the torque required to turn the engine, we can tell whether it is mechanically healthy. It only takes a couple of minutes, but we check everything: the electrics, hydraulics, etc. But we don't find problems here because the system won't let the engine advance from any stage until it's perfect, so it comes here perfect."

Occasionally, an engine is selected for a live test bench, a separate room with a viewing portal that houses a dynomometer, where the engine is fired up under its own power. The whole setup costs about €2 million (Dh10.4m), and AMG has two of them, for production engine testing as well as prototype testing. Our photographer had to be warned to turn his flash off for photos; a fire sensor inside the test room will think the flash is an explosion and activate the fire suppression systems.

"It takes two days to clean up; I don't think you want to see that," laughs Webber nervously. Maybe, but it certainly would make for a good picture.

Once the engines are finished their tests, they are packaged up and sent off to the Mercedes production plants, where they will be used right on the regular production lines for customer's orders of AMG cars. It's an enthralling process; OK, admittedly, not everyone might be taken by it as much as I was. But it explains why AMG engines are so revered in the performance world.

"For AMG, with our racing technology, we have always built engines by hand, with no exception," says Webber. "And this may sound like yesterday's technology; but our scanning system is tomorrow's technology. It's there to reduce problems and tolerances.

"But the quality is always coming from the mechanics; there is no way you can invent any system that can fully replace them."