A hundred years ago, Opel developed it’s first engine utilizing four valves per cylinder for use in the 1913 Grand Prix racing car. Little did they know at the time that this innovative technology would lay the groundwork for a future series of successful Opel four-valve engines, including the new line of SIDI and CDTI turbo engines.
The four-valve, four cylinder engine used in the Grand Prix car had a displacement of 4.5 liters, a power output of 110 horsepower and had two exhaust valves and two intake valves per cylinder. This was Opel’s first attempt at a four valve per cylinder internal combustion engine, a concept they would improve on the following year.
In 1914, Opel applied four valve technology to its gargantuan “Rennwagen” racing car, the largest automobile the company has made to date. The car, known as “The Green Monster”, utilized a 12.3 liter 4-valve engine that produced 260 horsepower, capable of propelling the 4, 400 pound giant to a top speed of 142 mph.
Four-valve technology died out in the automotive industry in the 1920’s before reappearing in the late 1950’s, once again in racing applications. It wasn’t until 1979 though that Opel put the technology into the average consumers reach. In order to compete in the top class of rallying at the time, known as Group 4, Opel had to produce a road going model of it’s Ascona 400 rally car. While the rally car produced 240 horsepower from its 2.4 liter engine, the street legal version was de-tuned to 140 horsepower.
By the 1980’s four-valve technology had become extremely appealing, mostly due to providing more power while using less fuel and reducing exhaust emissions. In 1988, Opel introduced its first mass produced model with four valves per cylinder, the now iconic Kadett GSi 16V. The 2.0 liter 16v engine, which was built in cooperation with Cosworth, produced 150 horsepower and 115lb-ft of torque, 90 percent of which was available from 3100 to 6000 rpm.
The same technology was used in the Formula 3000 racing engine, where it helped Opel score 164 victories in Germany alone. This engine would later form the basis for the Opel’s first turbocharged gasoline engine, which debuted in the 1991 Calibra Turbo 4×4.
By this time, four-valve per cylinder engines had spread across Opel’s entire powertrain lineup including in the smooth 3.0 liter inline six engines offered in the top-of-the-line Senator and Omega.
Opel continued it’s tradition of innovative four-valve engines when the company became the first automaker to combine four-valve technology with direct injection and turbocharging in a diesel engine. with the Ecotec DI 16V engines.
Now, 100 years later, Opel is still using four-valve engine technology to help deliver improved power and efficiency from its engines. The German automaker is continuing its tradition of innovation too, as it says 80 percent of its power train lineup will be completely renewed by 2016.