THE INTERNAL COMBUSTION ENGINE
ORANGE, CONNECTICUT -- The internal combustion engine has meant a great deal to the growth and character of America, but recently, in light of its increasing numbers, and with gasoline prices skyrocketing, it has come under severe criticism.
Research organizations throughout the world continue to spend millions of dollars each year in an effort to develop an alternative to the internal combustion engine. Steam, electricity and nuclear power have been mentioned in the past as possibilities, but the design, tooling, manufacture and maintenance of such systems are still years away from implemention.
As far back as 15 years ago, the need to regulate engine exhaust emissions was recognized. With more than 100 million cars on the road in the U.S. alone, it was imperative that pollutants be controlled, as the quality of the air in some of the nation's largest cities was being severly affected.
Thus, in 1966 the U.S. Congress acted. The Clean Air Act, sponsored by Senator Edmund Muskie (D-Me), mandated a systemized reduction of auto- mobile exhaust emissions and imposed standards on both domestic and imported automobiles.
One of the imported car manufacturers that felt the effects of the Clean Air Act was Sweden's Saab. At the time (1966), they were importing the Saab 95 and 96 models into the United States. That series of cars was powered by three cylinder two-stroke engines, later superceded by a German-made Ford V-4 engine. However, Saab-Scania was at the same time developing a new, larger and more sophisticated automobile, the Saab 99.
Faced with the realization that the new exhaust emission requirements would get progressively more stringent, Saab decided against using an interim engine that would have to be replaced with a cleaner version within three or four years. They contracted with Riccardo Brothers Laboratories of England to design a power plant with the primary objectives of low exhaust emissions and good fuel economy.
At the same time, Standard Triumph of England was looking for a new engine for their Triumph model and through an agreement with Riccardo and Saab, they became partners. Standard Triumph, now a division of British Leyland, would manufacture the engines to Saab specifications and would also build engines for use in their own cars.
The Saab 99 was introduced in the United States in 1969 with the 1.7 liter engine that resulted from this joint venture. The engine, which was designed with five main bearings, was canted at a 45 degree angle in the engine bay for easier serviceability. More importantly, it met the 1969 emission standards.
In 1972, the emission regulations were ecoming more strict. In an effort to provide more precise control over the air/fuel mixture and thus increas- ing fuel economy, electronically controlled fuel injection, introduced as as option in 1970, was presented as standard equipment on all Saab 99's. With the introduction of fuel injection, horsepower was increased to 97 @ 5,200 rpm.
However, the engineers at Saab were still not totally satisfied with the engine performance. They took note of the emission requirements scheduled for the middle 1970's and recognized the need to further develop the basic 99 engine design. So in 1972, Saab-Scania AB took over complete control of design and manufacture of the engine. A facility at the Scania truck plant in Sodertalje, Sweden became the new source of the Saab 99 engine. When the 1973 models were introduced in the United States, the Saab engineers had increased the engine displacement to 2 liters (1.950 cc).
But, there were some other major changes: The compression ratio of the engine had been reduced to 8.7:1 and a new cylinder head design was intro- duced. A double link cam chain was now being used and a redesigned cam shaft support bearing assembly provided better lubrication to the system. Bigger valves and intake and exhaust ports provided for improved efficiency which, coupled with the new combustion chamber configuration, also led to reduced emissions. All in all, the changes went a long way towards helping the engine run leaner, cleaner and stronger.
In late 1974 when most automobile manufacturers introduced their 1975 models, they often included a new and expensive piece of standard equip- ment - the catalytic converter. In fact, in the state of California, which had set emission requirements even tougher than those established by the Federal Environmental Protection Agency, only two cars could initially qualify without a catalytic converter or thermal reactor: The Honda CVCC with the radically designed "stratified charge" engine, and the Saab 99 with the same basic system Saab had employed on previous models, but with the newly developed Bosch Continuous Fuel Injection System and air injection.
What stunned many automobile industry insiders was that Saab, in addition to meeting all emission requirements without a catalyst, had actually increased horsepower to 115 (110 in California) and gas mileage. In addition, all Saabs for 1976 can run on regular leaded or unleaded fuel, a convenience most other cars can no longer offer.
The engineers at Saab-Scania plan to continue using the 2-liter power plant through the early 1980's. Perhaps the history of the Saab 2-liter engine can best be summarized by a phrase from the EPA status report of January, 1975, "Saab has always been one of the leaders in emission control despite their small size and low U.S. sales volume."