The “Clean Air Act” was passed by the US Senate in 1970, it setting the scene for emissions standards and emissions control equipment such as the catalytic converter. The timing was perfect for one Soichiro Honda , who had designed a CVCC stratified-charge engine, which not only met the U.S. emission standards without a catalytic converter but also met the stringent Japanese emission standards. In 1975 Honda exported the Honda Civic CVCC 1500 to the U.S. The four-door vehicle had a wheelbase of 2280 mm (90 in) with a front track of 1300 mm (51 in) and rear track of 1280 mm (50 in). It had a curb weight of 730 kg (1610 lb). The engine was an inline four cylinder mounted transversely with a 15° incline forward. The 1.5-L engine had a bore of 74 mm (2.91 in), stroke of 86.6 m (3.41 in), and a compression ratio of 8.1:1. Five main bearings supported the one-piece forged crankshaft. A single belt drove the overhead camshaft that operated three valves per cylinder. In the stratified-charge engine there was a tiny auxiliary chamber atop the main combustion chamber. Thus there was one valve for the auxiliary chamber and one for the intake and exhaust for a total of three valves per cylinder.