Ford Cosworth BDG

In 1967 Harley Copp, Walter Hayes and Henry Taylor reached an agreement with Cosworth to develop an engine for Ford of England. The objective was to develop and engine with better performance than the twin-cam Lotus-Ford. Keith Duckworth was engaged full-time on the DFV engine so Mike Hall took on the design responsibilities. The new engine was based on the Ford Kent block and would use the same basic cylinder head breathing as the earlier FVA 4-cylinder and the V8 DFV.

The agreement between Ford and Cosworth was for the design and development, not the building of engines. Design started in May of 1967 and the first 1600cc engine ran in June of 1968. The BDA means Belt-Drive Series A, which refers to the way the camshafts were driven. When introduced it was the first British engine to use cogged belts to drive the camshafts. The belt required was the same size as the one that had been developed and refined by FIAT for the 124 Sport Spider.

From Cosworth’s perspective the BDA took on a life of its own. In 1970 the BDB version was introduced. This was developed for Ford for use in the Escort RS1600 for rallying. The bore was increased for a capacity of 1700cc. According to Cosworth’s Mike Hall, the BDA just snowballed into the “Meccano set” of engines. By the mid-1970s the various BD engines accounted for over half of Cosworth’s turnover. Modifications were introduced by Cosworth and several other companies. The company continued to produce kits of parts to build up BD engines into the 1980s.

Ford used the BDB and BDC for the Escort rallying and racing programs. The BDD was a 1700cc engine built for the emerging Formula Atlantic category. In 1972 the 2-liter BDE was built for Formula 2. The BDF was an improved development of the BDE. In 1973 the BDG was introduced, it featured another increased cylinder capacity and produced 275 bhp. The first versions had a cast iron block, but later engines had an aluminum block.

The BDG had a capacity of 1975cc/120.5 cu in. The compression ratio was 12.0 to 1 for a horse power rating of 280 at 9250 rpm. The cylinder numbering was 1 – 2 – 3 – 4 front to rear with a firing order of 1 – 3 -4 -2 .

Cosworth Ford BDG