Article: Driving the Ex-Birkin Blower-4½ Single-Seater Bentley (Page 4 of 8)
Extract from: Motor Sport, by William Boddy, October 1973
Absent from the Autumn races, the single-seater was run in the BRDC 500-Mile Race. George Duller was appointed as co-driver to Birkin but in practice they experienced a front tyre burst and a wild skid and Duller never seemed to like the blower-4½, which he couldn't tame by talking to it, as he did a horse. In the race the Bentley proved it was no marathon runner, making a series of pit stops, and finishing 9th and last. Dorothy Paget withdrew her support for Birkin's team cars that winter but retained the single-seater.
Those who remembered the car in its better days were delighted that it made a re-appearance at the 1931 Whitsun Meeting. Birkin had now come into the title, being nominated by his entrant, Miss Paget, as Capt. Sir Henry Birkin, Bt. Alas, the car was unplaced, its best lap 131.41 m.p.h. In the Gold Star race it was only lapping at around 127 m.p.h., the wind making it, a tricky car at the best of times, difficult to control. Clearly, something had to be done. What Birkin did was to call in G. E. T. Eyston, who recommended one of his Powerplus vane-type superchargers, to replace the former Amherst Villiers Roots-type. This was duly fitted, retaining the 2 in. SU carburetters, and to obviate icing hot water from the radiator was fed to the supercharger casing. On the Saturday before the August Bank Holiday, when Birkin was to make a special attempt on Don's lap record, it was Capt. Eyston who was seen in the Bentley, trying things out. However, the speed didn't want to go above about 134 m.p.h. and in the attempt Birkin did five laps, but never bettered 134.97 m.p.h. He did this on two consecutive circuits, so was presumably flat out. He was entered for only one race—handicap contests never appealed to him—and in this, the London Lightning Long Handicap, in which for once he wasn't on scratch, for Cobb's Delage gave the Bentley five seconds, Birkin managed a fine opening lap at over 108 and then lapped at 136.45 m.p.h., to finish third.
At the Autumn BARC Meeting Birkin found the position reversed, Cobb leaving four seconds before him, in the Cumberland Senior Long Handicap, his only race in the Bentley, although he won the Mountain Championship in a Maserati and drove a 2.3 Alfa Romeo. The Bentley gave him third place, behind Widengren's OM and the big Delage. The "500" was again a fiasco, Dr. Benjafield driving the car but the Bentley retiring with a stretched valve stem.
In his book, "Full Throttle", Birkin said he had managed unofficially to equal Don's lap-record a few days prior to the previous season's 500-Mile Race but in trying to better it the next day the Bentley caught fire as it was coming off the Belfast banking and Sir Henry had to stand on the seat and steer as well as he could in a crouching position before coming to rest. What Benjafield thought about such high-speed work before a long race isn't recorded! This, it seems, decided Birkin to revert to the original Villiers blower.
Birkin was disinclined to give up, the Bentley representing his link with the old Bentley days, and for 1932 the single-seater was repainted red and the cylinders were bored out 0.5 mm., raising the swept volume to 4,442 c.c. Later in the season, an extra oil pump was fitted to the nose of the supercharger, scavenging the sump and delivering the lubricant to the oil tank at the rear of the chassis, as the engine had been converted to dry-sump. Incidentally, as Birkin was so keen on "wearing the green" I wonder why the car was painted in the Italian colours?
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