Mazda’s Secret Weapon: The CNC Motor Factory

Everybody route now!

Everybody route now!


Of all global automakers, Mazda may be in the toughest position. As if it weren’t hard enough to be one of the smallest independent mainstream automakers left, it faces the thankless task of marketing an enthusiast-oriented brand as well. And without the support of a major partner now that Ford has departed its alliance with the Hiroshima-based automaker, Mazda is hustling to stay in the game. But the hottest fires produce the hardest metals, to borrow a phrase used more by marketing types than engineers, and Mazda’s fight for existence is producing some interesting innovations. As Dave Coleman, vehicle development engineer at Mazda’s North American Operations tells Wards Auto:

“We needed to approach that fundamental truth (of economies of scale) and find out if it’s still fundamentally true, or is there a way to engineer our way around it. And it turns out there is a way to engineer around it.”

Using the break with Ford as an opportunity to re-think its entire manufacturing and design process, Mazda went beyond the typical auto industry goal of reducing parts counts. Instead it targeted a reduction in the number of machines needed to build a set number of parts, a goal that pushed it towards Computer Numeric Control, or CNC machining. Essentially a computer-controlled machining tool of almost limitless flexibility, a single CNC machine can make a range of components that previously would have required multiple machines with multiple calibration. This flexibility is of particular importance to a small enthusiast manufacturer like Mazda, which requires small-volume engines without investing in new production lines and machining.

But the value of CNC machining in engine manufacturing is hardly limited to flexibility. It also saves weight, saves time and costs less. SAE Vehicle Engineering reports:

Example: 2.0-L Skyactiv block/pan assembly weighs 26.1 kg (57.5 lb); conventional 2.0 (“MZR” series) block/pan weighs 31.8 kg/70.1 lb. Block/pan on a 2.0 MZR with direct injection, sold outside the U.S., weighs 33.4 kg/73.6 lb.

Savings: 5.7-7.3 kg (12.6-16.1 lb), although a factor is Skyactiv’s split crankcase block, which is inherently slightly lighter than the MZR with a main bearing ladder.

The flexible process costs 70% less than a conventional fixed line, Mazda said. Equally impressive: The process reduces total machining time for a block from 6 h on an MZR line to 1.3 h for the new Skyactiv line.

A comparison of all the block machining processes shows why Mazda is able to reduce total time by 4.7 h.

Enthusiasts regularly praise Mazdas for their driving feel, and its clear that the brand’s famous sense of Jinba ittai (“the horse and rider as one”) has not been lost as it pursues greater efficiency and manufacturing innovations. Perhaps someday enthusiasts will understand that engineering breakthroughs on the factory floor are every bit as important to the development of fun-to-drive cars as new engine or suspension types. After all, without seemingly prosaic innovations like this shift towards flexible CNC-base engine design and manufacture, its unlikely that an independent, enthusiast-oriented brand like Mazda could even continue to build cars for long.