It would be right to take a moment to discuss the engine history from the early cars. In a way, VW, Audi and Porsche all come from the same roots, although Audi might be thought of as a branch on said family tree. We are not going to relate about Ferdinand Porsche, Adolph Whatshisname and all that. In the USA, VW engine history starts with the hardy 1100 cc motor of the first cars that were imported, and continues through a long line of air cooled engines. First sold in Beetles, the Notchback and Type 3 also used the early motor with variations in the cooling systems. Fuel injection began with D Jetronic in 1968 in the Type 3’s, and with L Jetronic in the 75 Beetle and Type 2 Van. The last of the German Super Beetles was sold in the 1979 model year, but the production of the early style Beetle continued in Mexico for over two more decades. This air cooled technology had proven itself worthy to survive deep cold and desert usage that daunted water cooled engines of the day.
The engine history of the early VW Vans copied the Beetles somewhat. Then the Vans changed to the Porsche 914 sourced air cooled motor in 1972. They were equipped with temperamental dual carburetors until the 1975 model began the van fuel injection models using the L Jetronic system similar to the Beetle. This same 914 motor powered the VW Type 4 cars which debuted in Germany in 1968, but was not seen on American roads until the 70’s. The 914 motor morphed into the first Vanagon air cooled engine in 1980, and continued half way through the 1983 model year. And this begins the engine history of the water cooled boxer motor, also known as the Wasserboxer.
The early VW Rabbit, Jetta, Scirocco and Dasher water cooled inline 4 cylinder motors were a 1600 with a Solex carburetor. The emissions controls were a veritable nightmare, and fuel injection was a welcome addition. That K Jetronic system was unique in that the injectors were hydraulically controlled by fuel pressure differences, and just started spraying and stayed on constantly instead of tiny pulse like the electrically operated D and L Jetronics injectors. This marked the system with the name CIS or Constant Injection System.
FYI: German translation: D stands for Druck, meaning pressure, and the systems had a vacuum sensor with inductive coils. Vacuum and pressure are seen as identical in European terms. Just that vacuum is below atmospheric pressure, or 1 bar, and pressure is above one atmosphere of pressure, or more than 1 bar. L stands for Luft, or air. These systems had a pivoting flap that measured the volume of air moving into the motor. K stands for Konstant, referring to the continuously spraying injectors. KE Jetronic is the next generation of CIS, which is electronically controlled.
Originally, Audi was sold at some Volkswagen dealers. Audi engine history in North America starts with the 4 cylinder 1.8 of the Audi 100 LS in 1970, equipped with a carburetor. The engine size increased to 1.9 in 1972, which got L Jetronic fuel injection in 1975. This motor was of Audi design origin and never made it into any VW models. The smaller Audi Fox entered the scene in 1973 with a 1.6 engine sourced from VW. The Fox and it’s Dasher twin were the first models to be shared by both car lines. A new model, the Audi 5000, was presented in 1978 with the first 5 cylinder 2.1 engines. When the Audi Fox was replaced by the 4000 series in 1980, it had the 1.6 engine, which increased in size to 1.7 in 1981, and to 1.8 in 1984. In late 1980 the 5 cylinder engine became available in the 4000 series. With the introduction of 4 wheel drive in 1984, the 4000S Quattro sported a 5 cylinder engine. Volkswagen had the Quantum model as the Audi 4000 doppelganger. The 5 cylinder also appeared in the 1984 4WD station wagon fondly crowned the Quantum Syncro, which was the equivalent of the 4000S Quattro.
All the Vanagon gas engines are horizontally opposed 4 cylinder engines with aluminum blocks and cylinder heads. Some times referred to as the “Boxer” configuration, because it has fists pounding out to the left and to the right, like a boxer. Metallurgical issues complicate the job of building and maintaining these engines. The water cooled Vanagon engines are prone to corrosion problems, and are the most sensitive to coolant condition of all the models.
All the upright L series 4 and 6 cylinder gas engines from last century had cast iron blocks and aluminum heads. The Rabbit was the introduction with a 1.6 liter engine, and was joined soon by the Dasher, Scirocco, and then Jetta. The Rabbit had the engine installed in the transverse direction, meaning from side to side. The Dasher and the Fox had the engines installed longitudinally. For decades every car that was of Volkswagen design had a sideways engine, everything car from Audi had a motor front to rear. When the Mark II series started in 1985, the engines had grown to 1.8 liters, and had more compression. In 1987, a 16 valve version literally stormed the market in an upgrade of the original pocket rocket, the GTi. 1990 saw the 16 valve motor increase to a 2.0 liter, with more power than many rival 6 cylinder engines. The VR6 motor was first offered in the 1992 Corrado, and soon was in the Jetta and Golf models, and became standard for the Passat.
The Gasoline engines have continued to develop through major changes in technology. Multiple valves per cylinder make for more power through better breathing. Variable intake manifold runner lengths allow higher intake efficiency at different rpm ranges. Variable valve timing (VVT), meaning changing the camshaft timing in relation to the crankshaft, gives better power in any rpm range accompanied by an increase in mileage. Stratified fuel injection (FSI) makes a rich mixture near the spark plug, but leaner further down the cylinder, increasing mileage again. Now starts the pages devoted to the engines in the cars we love and work on.