G4 History

26th April 2007

Designed by Ivor Walklett and first shown in January 1961 at the Racing Car Show though obviously developed some time before. The G4 was first designed to use the Coventry Climax 750cc engine as used by Lotus to win the index of performance at the Le Mans 24 hour race sometime in the late 50’s, however Coventry Climax never produced the 750 commercially.

About that time Ford introduced the 997cc 105E Anglia, with its large bore, short
stroke, hollow cast lightweight crank, OHV with individual ports seemed heaven sent. As fitted in the Anglia it produced 39 HP, quite a bit less than the 50/60 HP the 750 cc, aluminium Climax engine was likely to produce in the road trim. However the fledgling Cosworth Company and also Ted Martin soon got to grips with the 105E engine for formula Junior and F3.