“I found the key to the universe in the engine of an old parked car.”
—Bruce Springsteen in “Growin’ Up”
Cars have come a long way since Springsteen wrote his iconic song lyric. Adaptive cruise control, automatic emergency braking and hands-free driving are only some of the latest features in new cars, yet the internal combustion engine, the heart of modern conveyance, has undergone few changes since its invention in the late 1800s.
The History of the Internal Combustion Engine
The internal combustion engine is not one but a collection of many machines. Ancient Egyptian artisans used the flywheel in pottery crafting, and metalworkers as far back as the 15th century used the camshaft in forges to lift and drop triphammers.
It’s impossible to attribute the invention of the internal combustion engine to a single inventor — not that that’s going to stop us from trying.
The Drawbacks of the Steam Engine
What’s not to love about an engine that runs on water? Turns out, a lot. Steam engines incorporate a separate furnace, making them cumbersome, inconvenient and — for the mechanical engineers in the crowd — thermally inefficient.
Engineers were working on alternatives to the steam engine as far back as the 17th century.
What Is Horsepower?
The term “horsepower” can be attributed to James Watt, who improved on the design of the steam engine in 1763. Watt needed to prove that his steam engine could outcompete the primary form of transportation at the time: horse-drawn carriages (an engine that runs on hay and water).
Watt and business partner Matthew Boulton came up with a metric for measuring a horse’s power, arriving at a carrying capacity of about 33,000 foot-pounds per minute. Horsepower is now used everywhere to measure an engine’s power. For his efforts, Watt got his own metric named after him in 1960.
The Advent of the Internal Combustion Engine
French engineer Sadi Carnot was the first to outline internal combustion theory in his 1824 publication “Reflections on the Motive Power of Heat.” Decades passed. Engineers tried and failed to develop an engine that could run on the combustion of fuels — that is, until Étienne Lenoir came on the scene.
The Lenoir engine wouldn’t be considered the most efficient or powerful machine by today’s standards: the two-stroke engine utilized only 4% of the energy in its fuel. Still, it was perfect for powering water pumps, printing presses and other low-power machines.
So, internal combustion engines are possible, but could they possibly be efficient? Alphonse Beau de Rochas, another French engineer, thought so. His 1862 publication described the ideal operating cycle for an internal combustion engine, but he never actually built it.
Engineers ran with the idea and began designing engines powered by combustible fuels.
Combustion in Your Car Engine
Combustion is the chemical process that releases energy from igniting a mixture of fuel and air. Internal combustion engines, in which fuel ignition and combustion occur within the engine, covert the energy from combustion into mechanical work.
Here’s how it works:
- A fuel-air mixture is ignited.
- There’s combustion; thousands of small, controlled explosions.
- Heat and expanding gases push an engine’s pistons up and down—like the pumping legs of a bicyclist.
- The pistons spin the crankshaft through a system of gears in the powertrain, which moves the wheels of a car forward.
A Stroke of Genius
German engineer Nikolaus Otto invented a four-stroke internal combustion engine in 1876, dubbed the “Otto cycle engine.”
German engineers Gottlieb Daimler and design partner Wilhelm Maybach improved on Otto’s design in 1885, inventing the first practical internal combustion engine and carburetor, which allowed gasoline as a fuel source.
There is some debate as to who built the first motorcycle — Otto or Daimler. The win goes to Daimler for inventing the world’s first four-wheeled automobile: a converted stagecoach. Around that time, yet another German mechanical engineer, Karl Benz, built the first practical automobile.
The internal combustion engines of today have better performance (horsepower and 0-60 acceleration time) with reduced emissions, yet they are fundamentally the same as those designed by Daimler, Maybach and Benz.
Pedal to the Floor
The history of the internal combustion engine is fraught with misfires; it took engineers centuries to develop the technology under the hood of your car. If you’re interested in picking up where they left off, consider The University of Texas at Austin and its 100% online Master of Science in Mechanical Engineering.
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