Designed by Frank Costin in 1968 for Gloustershire based Formula Four manufacturer Johnny Walker and exhibited at the Racing Car Show in 1969 only one example is known to have been constructed. Powered by an 875cc Imp engine it featured an Aluminium body and modular spaceframe chassis patented by Costin which is reputed to be the "stiffest spaceframe ever constructed".
The car featured in Frank Costin's book "Flying on Four Wheels" and also in an Autosport Track Test on 20th November 1969 together with the JW4 Mk5. Imp Saloon driver Bill McGovern was lined up to drive the car for 3 events in the remainder of that season, but already the project was for sale in part due to Johnny Walker retiring from motor racing to focus on his machinery business.
In 1970 development Walker still owned the car and gave it to Tony Hilder, designer of the Piper and Harrison cars for further development who tested it under the name of Type AH.
For 1971 and now known as the JW4 Mk6 Walker took development of the car back in house and recruited Keith St John for development work and he reportedly had some sucess in races, however halfway through the season the car was involved in an accident hitting the bank at Lydden Hill suffering damage to one of the Magnesium rear rear uprights and the body. After the accident the car was advertised and sold in its damaged state.
The history of this cars development and subsequent sale is well document however less is known about its racing achievements (if any). Can any readers shed any light on what events or championships Johnny Walker, Bill McGovern or Keith St.John drove the car in or the results from these races?
Thankyou
