Science Fair Project Encyclopedia
Saab H engine
In 1981, Saab began lightening and redesigning the engine. The most-significant change was the elimination of a central shaft which powered the distributor and oil and water pumps. Instead, the distributor was directly driven by the overhead camshaft and the water pump was a separate unit, driven by a fan belt off the crankshaft pulley.
In 1982, Saab added Automatic Performance Control (APC), a knock-sensing system which allowed a much higher compression ratio (9:1 as opposed to 7.2:1) and this boosted performance from 145 hp (108 kW) to 155 hp (116 kW). This system also produced 20% better fuel efficiency and allowed the use of low-octane gasoline without causing engine damage.
In 1984, Saab added a 16 valve head, creating the world's first multi-valve turbo engine. They retroactively renamed the 8-valve version the B201 and used B202 as the name of the new multivalve unit. Another notable addition to the B202 were hydraulic valve lifters.
The B234 was a new 2.3 L (2290 cc) version with many changes. It was stroked by 12 mm to a square 90 mm bore and stroke. Also notable are the added balance shafts to smooth the large four's vibrations. The B234 was selected as one of Ward's 10 Best Engines for 1995 and 1996.
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