French Engineering Firms Join to Build Variable-Compression Prototype Engines

PARIS – French engineering firm MCE-5 Development says it has built a gasoline direct-injection version of its 4-cyl. variable-compression engine that generates 243 hp, 361 lb.-ft. (490 Nm) of torque and achieves 38 mpg (6 L/100 km) or better in the midsize Peugeot 407.

The mileage claim is undergoing independent validation now for the New European Driving Cycle, company CEO Jean-Francois Roche says.

Since presenting a diesel version of its variable-compression engine outside the Geneva auto show last March, MCE-5 has signed an agreement with another French engineering company, Mecachrome, which plans to begin making prototype engines in 2013.

In addition, MCE-5 recently attracted E24 million ($32 million) in new financing that should fund company development until 2014, when it expects to be selling its intellectual property. “Our objective is to have the first agreements signed in the next 24 months,” Roche says.

MCE-5 has invested E75 million ($100 million) so far on the development of an idea that has intrigued engineers since the beginning of internal combustion: that fuel can be saved if compression is higher than normal when the engine load is light, and lower at full throttle.

In most engines, compression is fixed at about 11:1 or 12:1, a compromise that limits the problem of unintended detonation at full throttle. MCE-5’s goal is to have a range of 6:1 to 15:1.

Michael Dick, Audi’s chief technology officer, recently was quoted in the leading German magazine Automotor und Sportas saying that at Audi, “there will be further steps to enable variable displacements and compressions.”

MCE-5’s approach is to have additional internal parts that control the height of the piston. The stroke remains the same, but the piston approaches the cylinder head closer under high compression, and less close under low compression. A special gearwheel connects the connecting rod to the crankshaft and a special rack positions the pistons.

The partnership with Mecachrome is intended to speed up an unnamed auto maker’s decision to invest in the technology, Roche says.

Mecachrome, which has made engines for Formula 1 racecars, is a supplier of precision machined parts to both the aerospace and automotive industries. The company intends to make the critical parts and to install capacity for manufacturing up to 40,000 engines a year by 2016-2017, assuming MCE-5 finds customers.

In an interview, Francois Laloyaux, Mecachrome’s executive vice president for automotive business, says the company will manufacture its first prototype engines in 2013.

Mecachrome, founded in 1930, was saved from bankruptcy in 2009 by public investment programs in France and Quebec, Canada, where the company has factories. In 2010, according to its website, it had revenues of E207 million ($276 million) and employed about 1,500 workers.

“With this agreement, an auto maker can avoid making its own investment in gearwheels and racks,” Roche says, the two essential parts MCE-5 has developed to control the movement of the piston and, therefore, the compression.

MCE-5 will remain an engineering company, not a manufacturer, he says. Auto makers that install engine lines for hundreds of thousands of units a year could use Mecachrome for a small series before making a major investment in a new line.

But Roche also has his eyes on those OEMs that might make a major investment in a new technology.

“It is imaginable that a new auto maker would want to mark its difference immediately with the latest-generation engine” by investing in a fullsize engine plant building variable-compression engines, he says. “Recent auto makers could have this ambition.”

MCE-5 is in contact with major auto makers in China, Japan, North America and Europe, he says.