Throwback Thursday - Secrets of a lost British supercar, 17 April 1985

Here’s one that slipped through the cracks. The Glenfrome Delta, the work of a small Bristol-based firm, was a stunning two-seat sports car that never got past the concept stage.

Glenfrome Engineering, run by father and son Ken and Michael Evans, spent 20 months building its mid-engined prototype, finishing it just in time for the 1977 Earls Court motor show.

The car didn’t snag any orders, but a wealthy Arab liked the bodywork and commissioned a converted Range Rover. That took Glenfrome into a very lucrative new direction as coachbuilder of bespoke Range Rovers destined for the Middle East.

The prototype Delta, meanwhile, was wheeled to the back of a storeroom and covered with a dust sheet for eight years. And then Autocar’s Bob Cooke was invited to drive the car.

“The past came flooding back as we blasted along the M32,” wrote Cooke.“The engine had a familiar sound, being the 1998cc, four-cylinder unit developed jointly by Saab and Triumph and used in the Dolomite Sprint.

“The suspension is Triumph GT6 front and Stag semi-trailing arm rear, and so felt familiar – a little crashy over bumps but sportily firm.”

While the Delta sat on underpinnings found in a scrapyard, its bodywork was the work of passionate, skilled craftsmen.

“Smooth panels, gentle curves and neat joints were all made freehand in sheet aluminium,” wrote Cooke. “Ken Evans laid out the engine, running gear and suspension on a workshop floor and marked a few chalk lines on the ground. No design or technical drawing ever existed for the Delta.

"Evans and Viv Hunt, an aluminium craftsman, started with a steel chassis welded up to hold the mechanical components together. Then the outline of the body was framed in welded-up light tubing and the aluminium sheet bent and rolled to fit. When the panels matched up, the tubing framework beneath was cut out."

Unsurprisingly, the eight-year-old,unsorted show car wasn’t stunning to drive, although Cooke could sense potential.

“The Delta uses 13in wheels,so the car is effectively undergeared,” he wrote. “It did have one saving grace,though, in that acceleration was good enough to winkle a way in front of the traffic and the engine flexible enough not to call for lots of gear changing.

“Production versions would have given much more exciting performance – the plan was to fit a turbocharged Rover V8 and a ZF five-speed transaxle.”