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If Technical Advisor Michael Blanz ever needed any karmic confirmation he was headed down the right path, it came stepping off the elevator late last year at the Cummins Technical Center in Columbus, Indiana (U.S.).

There, in the corner of the lobby of the Tech Center office building, amid the models of classic Cummins engines through the years, Blanz saw a small piece of equipment on a work bench that he hadn’t noticed before. The machine was just a little bit bigger than what you might see in a hobbyist’s home workshop today.

It was the lathe Cummins founder Clessie Cummins used at his California home to invent the engine compression brake, commonly known as the “Jake brake.” It has helped trucks safely traverse mountain roads for more than 50 years.

“I walked over to check it out and I couldn’t believe it,” Blanz said of the lathe, which was on display in anticipation of the company’s 100th anniversary celebration this year. “For me and my team this was truly inspirational. I can’t tell you what an impact it had on us. “


Why did an old lathe mean so much to Blanz and his team? Sometimes an older innovation can inspire new ways of doing things.

While Blanz’ and his team’s project has nothing to do with slowing a vehicle down, it does use the same general concept of altering the engine’s exhaust valves to provide power for another purpose.

Clessie Cummins takes off on a barnstorming tour to promote Cummins

Clessie Cummins, truly one of the great inventors of his time, used engine compression to slow the drivetrain so the vehicle would reduce speed without the driver having to put his or her foot on the brakes, thus preserving the brakes and avoiding a runaway truck. During his barnstorming days demonstrating the potential of the diesel engine across the United States, Cummins had personally experienced the terror of flying down a mountain road with little or no brakes.

Blanz and his team have been working to use a similar concept to prevent the degradation of the catalyst often used in diesel engines to remove pollutants from engine emissions that cause smog.

The team calls its invention “CvC” (trademark pending), which stands for Clessie vs. Clessie. It essentially pits the founder’s pioneering work on diesel engine torque against his equally innovative break-throughs on engine compression to produce the heat necessary to protect the catalyst. Here’s how:   


In today’s engines, the effectiveness of the catalyst can be diminished over time if the accumulated gunk isn’t burned out occasionally. If the gunk isn’t removed, the catalyst might have to be replaced, which is a very expensive repair for the engine owner.

The system developed by Blanz and his team obtains the heat necessary to regenerate the catalyst through engine compression. But instead of using the engine brake compression to slow a vehicle, the brake is engaged on only half the cylinders while the remaining cylinders are still fueling against the retarding load of the braking cylinders. The net result is a dramatic increase in exhaust heat, which the catalyst requires to remove the gunk.

Work on CvC is ongoing, but if all goes according to plan, the innovation should be especially helpful to the owners of off-highway engines solely using Selective Catalytic Reduction (SCR) to address emissions. The SCR process occurs when a liquid agent (urea) is injected into a special catalyst. The urea reacts with the engine’s exhaust inside the catalyst to reduce various regulated engine emissions.

Like Clessie Cummins, Blanz loves to innovate and he and his team are excited to continue working on CvC.  They are especially excited after what they see as encouraging sign from the company’s founder.

Michael Blanz (second from right) and his team gather around the lathe Clessie Cummins used to invent the Jake brake.