1975 Rennmax BN7 F2 Single-Seater

Description

Designed and built by Sydneysider Bob Britton, Rennmax Engineering constructed a series of successful open-wheeler and sports racing cars starting in the 1960s and he continues to design and build his own creations to the present day.  Trained as an apprentice fitter and turner, Britton worked from a dimly lit converted garage behind his house in Ashfield and a period article in Sports Car World’s May 1964 edition mentions he rarely attended race meetings, preferring his drawing board and tools.  Britton’s first project saw a major update Noel Hall’s Cooper Type 51 in 1962 using the Climax engine and running gear in a custom-made frame closely modelled on the Lotus 18.   This in turn led to an order from Barrie Garner to build a Lotus 23-style rear-engined sports car for hill climbing, followed by a number of Formula Junior cars.  By this stage Britton had adopted his own numbering system, starting with BN1, although a number of projects fell outside this nomenclature, including the most powerful car he built, the MRC sports car built for Lionel Ayres in 1968 using a Traco Oldsmobile V8 engine.  Updated with a Repco 740 V8 in 1969, the car took second overall in the 1971 Australian Sports Car Championship.  The BN6 for Doug Heasman was Britton’s attempt at building a monocoque Formula 2 car in 1974, followed by the ‘production’ BN7 version of 1975, three of which were built for Terry Quartly (raced by Bob Muir), Andrew Miedecke (sponsored by Grace Bros, later raced by Ross Fleming) and Ross Switzer, plus one additional car completed by West Australian John Siccardi using the original jigs and moulds.  Reportedly taking inspiration from the Jaguar D-type, the BN7’s frame was designed around a central monocoque fabricated from aluminium with front and rear spaceframes.  By this stage Rennmax had relocated to Annangrove, close to Amaroo Park, where Bob Britton’s workshop remains today.