A wealthy privateer and Lloyds underwriter with other extensive manufacturing, garage and transport interests, Ken was born near Stoke on Trent, where his father was Chairman and founder of G.H.Downing Ltd, a large group producing roofing tiles, bricks and clay products. Though his father had no great interest in motor racing, his mother was taught to drive by Perkins, the chauffeur and riding mechanic to Sir Henry Segrave.
Born in the middle of World War I, Downing started racing after World War II making his competition debut in 1948 on the Eastbourne Rally and wining the novice award. His racing debut came at the inaugral Goodwood meeting, taking 2nd place in his Healey road car despite being left on the grid when he let in the clutch only to find he was still in neutral.
In 1949, he bought Leslie Brooke’s Brooke Special that had raced at Brooklands. Ken bought it with the Riley engine but felt it was not very competitive. However he did take a 3rd and two 4ths in Goodwood Handicaps, a 7th in the Lavant Cup and an 8th in the Madgwick cup.
His first Connaught came in 195o and was an early sports car but rather than have it with a 1.75 litre engine he asked for a 1.5 litre version so that he could run in the smaller class. He then stripped the body and had a new lightweight body with cycle wings built in Newcastle under Lyme and with this he began to make a name for himself and was a regular winner. Ken was also persuaded to put a 2ltr Delage V12 engine into the Brooke special. Oil leaks plagued it's first outing at Gamston although he did take win with his Connaught. Most of the year was spent sortimg the Connaught out, he did take 3rd in Class at the Gravesend speed trials and a 3rd at Silverstone, despite having to finish the race in third gear after the gear lever came off. He notified his mechanics of the problem by throwing the offending item to them as he passed the pits. He also raced a Healey in Standard Sports and Saloons, winning at Castle Coombe, the Gambson Handicap, and finishing 28th at the Silverstone International Trophy.
He continued competing with the Connaught until the end of 1951 becoming a regular winner in club races taking 15 victories and only being unplaced once. His wins included; Gamston, SIlverstone, Ibsley and Winfield, along with many more 2nd and 3rd places. He won the sports class at the Replow Speed Trials in the Connaught and took his Healey road car to victory in the Gamston Handicap with 2nd at Silverstone and Winfield. He also co-founded the Cheshire Car Circuit Club which started racing at Oulton Park.
At the end of 1951 he decided to buy one of the new Connaught A-type 2-litre Formula 2 cars. His was the first customer car, chassis 03, and when the CSI changed the rules for Grand Prix racing in 1952 to allow 2-litre cars to compete, he suddenly found himself with a Grand Prix car. He oiled a plug, broke the drive to the magneto and blew the head gaskett in the Silverstone International heat. Despite this he still managed to start the final and finished 13th.
He then entered the British Grand Prix in July that year. His practice time of 1 minute 56 seconds put him on the second row of the grid behind the three factory Ferraris of Farina, Ascari and Taruffi and Manzon’s Gordini. Though Ken’s time was equalled by Reg Parnell (Cooper Bristol) and Mike Hawthorn (Cooper Bristol) Ken was the first to set the time and so became the highest placed British driver on the grid.
At the start, Farina hesitated and this baulked Downing letting Reg Parnell and Alan Brown dash ahead of him. However, he had worked his way to fifth place behind three Ferraris and Mike Hawthorn’s Cooper when he spun avoiding a backmarker. He eventually finished ninth. He retired from his only other GP, the Dutch.
He had two other good results that season, winning the Madgwick Cup at Goodwood and then looked set to win the GP des Frontiers at Chimay having led from the first corner. However he backed off too early in the spectator lined streets and was pipped on the line. He took 4th at Boreham and in a Goodwood Handicap and set an F1 record at the Prescott hillclimb that stood for five years. He also won a Boreham sports car race in his old Connaught and took 2nd in the Handicap and 10th in the F2 race. While at Silverstone he rounded his year off with third in both the Allcomers and Handicap races.
At the end of 1952 Ken sold all his cars and briefly bought an Aston Martin DB3 sports racing car. Despite a win at Silverstone there was little forthcoming success and he sold it half way through the 1953 racing season to concentrate on his chairmanship of the family business eventually retiring to Monaco.
His daughter Ann (who died in 1980) was formerly married to motor racing entrepreneur Paddy McNally, Chief of the Allsport Management company which controls corporate hospitality and circuit advertising throughout the FIA Formula 1 World Championship. His nephews Ian and David Skailes, both members of the BRDC, raced internationally in the 1970s.