The History of the Diesel Engine

The History of the Diesel Engine

Affirm CollaboratorNovember 22, 2019

In the last ten years, the diesel engine has experienced a surge in popularity. Turn on the TV and you can watch shows dedicated to the diesel engine and all its power. One can attribute that popularity to a few things, like the high price of gas and the environment. While gasoline prices continue to rise, people are looking for alternatives so they can save some money. Diesel fuel is cheaper to buy than gas, and the engine will last much longer and keep running for hundreds of thousands of miles. Diesel engines also don’t give off as many emissions as gas, so the greenies out there can feel better about driving them. The real reason, though, is because diesel trucks are kick-ass, rolling strong, and awesome. Before you climb up into your Ram with the Revmax 48RE and super-swamper tires, know what you’re driving. Learn the history of the diesel engine and show some respect.

Origins of the Inventor

Rudolf Diesel was born in Paris, France in 1858 to German immigrants. His parents chose Paris to settle in and start their family. They were exiled from Paris when the French Parliament declared war on Prussia and the Franco-Prussian War broke out. The Diesel family fled to London in 1870 when Rudolf was 12 years old. From London, Rudolf went to live with his aunt and uncle in the Bavarian town of Augsburg, which happened to be his father’s home town. His parents sent him there to continue his schooling and attend the Royal County Trade School in Munich. He proved to be a protégé there under the tutelage of refrigeration pioneer Carl von Linde. Rudolf graduated at the top of his class, and that education laid the groundwork for everything that was to come. After graduating, Diesel went to work for Von Linde at his firm in 1880.

Near-Death Experiment

Diesel’s early work with the Linde company was centered around refrigeration research and development. He was ambitious, though, and wanted to branch out from refrigeration. His understanding of thermodynamics was so deep he began to experiment with steam engines and their efficiency—or their lack of it. He was trying to create an engine that didn’t waste heat during the combustion process and would get the most out of the fuel source. He almost killed himself when one of his experimental ammonia vapor steam engines exploded. Diesel was badly injured, and his recovery took several months. During his recovery, he kept planning his next engine based on the theoretical Carnot cycle. The theory says that there is an upper limit on the efficiency that any classical thermodynamic engine can achieve during the conversion of heat into work.

The Diesel Engine Evolves

Diesel’s understanding of thermodynamics and his knowledge of steam-powered engines’ inefficiencies guided his work. Steam engines of the day were heavy, large, expensive to run, and wildly inefficient. They operated at a 10% efficiency rating. Rudolf set out to take all his knowledge and learning and create a more efficient engine.

He had many failures at first, but he didn’t quit the pursuit and eventually succeeded. His engine was more efficient because of how it ignited the fuel compared to others on the market. Gasoline engines compress fuel and air together and then ignite the mixture with a spark. A diesel engine only compresses the air and makes it hot enough to ignite the fuel once injected into the cylinder. Also, the higher the compression ratio, the less fuel is needed. Unfortunately for Diesel, the early engines were more efficient but had massive reliability problems that left customers furious. Despite all that, he never gave up and continued to tinker and adjust his engine.

Diesel felt that his design would allow smaller businesses to compete with the larger ones in any industry. Diesel didn’t invent the engine that bears his name, but he significantly improved it. His was an evolution of the “hot-bulb” engine. Herbert Stewart and Richard Hornsby patented the “heavy oil engine” in 1890, a full two years before Diesel filed and received his own. The hot-bulb engine was a fuel-injected engine that ran on paraffin oil, a fuel that is like kerosene and diesel. The biggest difference between the two engines was the compression ratio. Diesel’s engine used high compression to kick off ignition and the hot bulb engine created the burn by spraying fuel into a hot pre-chamber. Diesel’s engine was superior because the operator didn’t need an external heat source to get it moving. The hot bulb chamber, on the other hand, had to be heated up before it was usable. Overall, the Diesel engine was more adaptable and had better control over fuel injection timing.

Diesel’s Death

On September 29, 1913, Rudolf Diesel boarded a ship traveling from Belgium to England. A day later, a soldier on the boat looked overboard and spotted a body floating in the water. It was Diesel. He was on his way to England to attend a groundbreaking for a diesel engine plant and to meet with the British Navy about putting his engine on their submarines. The German navy was already using the same engine on their submarines, though. Immediately, conspiracy theories began flying, and everyone believed that German agents murdered him to stop the deal from happening. World War I was months away from starting, and the rivals were raising arms for the conflict. Before he left on the trip, Diesel gave his wife an envelope, instructing her to open it in one week. It contained money and financial statements showing that he was broke. What likely happened is that he jumped over the side and committed suicide.

Modern Engines and Output

The modern diesel engine is much more powerful and efficient than the original. Today, they are built rugged to withstand the rigors of higher compression and performance standards. Because of that, they will go much longer than previous models before needing tune-ups or repairs. The longevity of diesel engines is appealing to fans, and the increased torque and power output by the engines leads to increased towing power. That’s why all heavy machines and tractor trailers have a diesel power plant; they can do a lot of work.

The History of the Diesel Engine infographic