Ambulance Chassis as designed for the GLC
The Ardun Engine Conversion
The company’s involvement in the Ardun overhead valve conversion was, in my view, an ill judged attempt to provide an alternative to the outdated 30HP 3442cc Ford engine. From the company’s point of view there was the potential of 140 brake horse power by converting to a modern overhead hemi design.
However, while the literature was easy to produce the reliability of the conversion was sadly under developed and fell well short of Zora Duntov’s claims.
The biography by Jerry Burton sums up Zora’s Ardun conversion as it had delivered neither the performance nor the reliability claimed in his advertising. In fact, the engine suffered from a litany of problems including inadequate rocker shaft support, overweight valves and push rods, coupled with the tendency to lack adequate oil drainage from the cylinder heads. The rockers which came from raw casting, were difficult to machine to the dimensions specified by the Ardun Corporation drawings, plus there was evidence of porosity found on failed items.
Over the last ten years a redesign of the cylinder head has been carried out by Don Roscoe, which has breathed fresh life into the Ardun conversion.
