1975 Chevrolet Cosworth Vega

The Chevrolet Cosworth Vega is a subcompact four-passenger automobile produced by Chevrolet for the 1975 and 1976 model years. It is a limited-production version of the Chevrolet Vega, with higher performance. A total of 3,508 Cosworth Vegas were made and were priced nearly double that of a base Vega - and only $900 below the 1975 Chevrolet Corvette.

The Cosworth Vega Twin-Cam engine is a 122 cu in (1,999 cc) inline-four with die-cast aluminum alloy cylinder block and Type 356 aluminum alloy, 16-valve cylinder head with double overhead camshafts (DOHC) held in a removable cam-carrier that doubles as a guide for the valve lifters. Each camshaft has five bearings and is turned by individual cam gears on the front end. The camshafts, water pump and fan are driven by a fiberglass cord-reinforced neoprene rubber belt, much like the Vega 140 cu in (2,294 cc) engine. The cylinder head has sintered iron valve seats and cast-iron valve seats. Race-bred forged aluminum pistons with heat-treated forged steel crankshaft and connecting rods enhance durability.[6]

The engine has a stainless-steel exhaust header and Bendix electronic fuel injection (EFI), with four injector valves, an electronic control unit (ECU), five independent sensors and two fuel pumps. Some 60 lb (27 kg) lighter than the SOHC Vega engine, it develops maximum power at 5,600 rpm and is redlined at 6,500 rpm, whereas the SOHC Vega engine peaks at 4,400 rpm and runs to 5,000 rpm. Final ratings are 110 hp (82 kW) at 5,600 rpm, 107 lb⋅ft (145 N⋅m) of torque at 4,800 rpm. 3,508 of the 5,000 engines were used. GM disassembled about 500 and scrapped the remainder.