Type 403

The Type 403 is the logical development of the aerodyne. The complaints of the 401 were systematically tackled but such was the effectiveness of the body design that the major differences are all beneath the skin.

The most obvious external differences are as follows:

• Radiator grille inserts are silver painted. The apertures are highlighted by the use of chrome trims as with the 401 and 402.
• The chrome numerals 403 are fixed onto the sides of the bonnet and also are fixed centred at the rear onto the boot lid.
• House badges are fixed on the flanks of the front wings, surmounted by the Bristol Pegasus symbol, illustrated to the right. House badge colours are as 401.
• The colour on the hub cap, bonnet and boot badges inlay and decals is changed from yellow to red.
• To chassis 1409, cars are fitted with the Lucas PF770 headlamps with flat glass. Cars from chassis 1410 are fitted with Lucas P700 headlights with curved glass.
• Combined body mounted side and fog lamps used up to chassis 1480 are Lucas 055181B. From chassis 1481, Lucas FFT.462P lamps are fitted. This type does not include a separate sidelamp. It seems logical therefore to assume that some time after this, wingtop sidelights were introduced to the specification though it should be noted that earlier cars were fitted with the later specification wing mounted sidelights retrospectively. The wingtop sidelight units look remarkably like those fitted on the Austin A30/35 series cars. The earliest chassis frame I have recorded with these additional lights originally fitted is 1524 which is quite surprising 43 cars on!
• On the mechanical side, the brake drums were changed to ‘Alfin’ or aluminium finned type on all four wheels initially, then on front wheels only later, because they were so efficient the rear wheel braking system became overcooled.
• The braking system pedal actuating mechanism was also modified to improve effective pressures and to cope with increased performance. A complaint of drivers not used to the low drag effect of aerodynes in general, was that during braking from higher speeds, they frequently had the impression the brakes were not working, even though they were. The wind drag coefficient was so low compared to that achieved by more mass market cars of the period that they had come to expect some marked slowdown when the accelerator pedal was lifted. In the case of the aerodynes this effect was considerably reduced — a benefit of the many hours of scale model wind tunnel testing and high speed trials of the body shape up and down the runway at Filton.
• To assist handling, an anti-roll or sway bar was fitted as standard to the front suspension system.
• The standard engine was the 100A for all but the later cars. The 100B and 100B2 engines were available as was the Laycock de Normanville overdrive. Both units were fitted. Many late 100A units were of an upgraded specification, identified as 100AB2.
• As with its predecessors, an Enots one shot hydraulic chassis lubrication system was fitted at the front suspension and steering gear and a splash activated gravity drip feed system at the rear suspension supplied from the differential.

403 Special or Non Standard Body cars

403 NSB

Chassis number 1348 has been very professionally modified to form an attractive drophead body cut down after the fashion of the 402 and is now classified a 403 NSB. The rear of this car is not as the standard 403 and not as the 402. It is pleasing to note that the owner has reinstated all of the 403 numbers on the body including the new boot lid. It is not known if the revised body was fitted internally with additional bracing.

The previous car is now classified as a 403/2. The following cars are now classified as normal 403s. The confusions have now been largely cleared up. — CPKS 2008

403 NSB

Chassis number 1485 is fitted with a walnut dashboard. Not known whether this is a later addition or original ex works.

403 FOLLAND

Chassis number 1502, registered as SHW 67, was fitted with a recessed one piece perspex front windscreen. It is pictured in the first of the Club videos. Owned originally by Folland Aircraft Co. Ltd, the car was badly damaged whilst being driven by its subsequent owner and was treated as an insurance write off. He told me that his survival of the ordeal had been due in part to the full aircraft style seat harness which had also fitted and which justifiably he transferred to his next Bristol.

403 NSB

A third car, a slight puzzle apparently registered WMF 917, was displayed at the concours in Bristol circa 92/93 wearing 403 numbers, and fitted with a one piece flush glass windscreen. This one looks similar to the unit fitted to the Morris Minor. Flashing trafficators have been set into the front and probably rear bumpers possibly ex.Volkswagen. Can anyone identify the chassis number? The registration was last reported by a club member on 401 chassis 850 — which was also reported fitted with a 3 cyl. Diesel engine. However no club member has reported this registration moved onto a 403 chassis. If this particular car is built on chassis 850, it is not and never was a 403 and should not be bearing 403 numbers.