page_title: Lotus 23
section_title: The 23
hierarchical_section_title: Lotus 23 / The 23
caption_attribution_description: Deutsch: Lotus 23 B, Baujahr 1962, beim AvD-Oldtimer-Grand-Prix auf dem Nürburgring
context_page_description: The Lotus 23 was designed by Colin Chapman as a small-displacement sports racing car. Nominally a two-seater, it was purpose-built for FIA Group 4 racing in 1962–1963. Unlike its predecessors Lotus 15 and 17, the engine was mounted amidship behind the driver in the similar configuration developed on Lotus 19.
context_section_description: To comply with FIA rules, it had a regulation trunk space to the right-rear of the driver, a windshield wiper, a horn, pairs of headlights and tail lights, rear center license plate light, a wire-operated emergency brake, and a mounting space for one spare tire under the front body. The 23 used a wider version of the Lotus 22 space frame, clothed in a fibreglass body.
  The front suspension was a typical double wishbone arms with outboard coil/damper unit using the Triumph upright made by Alford & Alder, Triumph Herald rack and pinion steering, and outboard Girling non-ventilated disc brake. The rear had the top link with lower reversed wishbone, top and bottom radius arms with the top arm at the height of the halfshaft, combined with the outboard disc brakes and coil/damper unit.  Unlike the arrangement for Lotus 20 suspension, the halfshafts had Metalastic rubber 'doughnuts' on the inside, carrying no cornering (side) forces.  The side forces are carried by the lower wishbone, together with the top 'I' arm link, which connects the tail end of the upper side tube in the frame with the extended top end of cast alloy upright.
  The tie-rod end, front top and bottom wishbone outside joints and the rear lower wishbone inside joint were Heim joints. The rest of the suspension joints were rubber joint, with joint-mounting pipes welded onto the ends of suspension arms.  While most of the suspension arms were in common with Lotus 22, the angle of the rear radius arms on the plan view was different from the narrower-frame Lotus 22, so they were not interchangeable with the 22.
  It was originally intended for engines of 750 cc to 1300 cc (45-80ci) with a Renault 4-speed transaxle, but had a 5-speed Hewland Mk.III in production, which used the entire Volkswagen magnesium alloy transaxle case in upside-down configuration, housing bespoke straight-cut gears with dog-rings, and the Volkswagen differential gear set.  Unlike the later Mk.IV, the Mk.III had the shifter rod at the end of the VW nose casing, so the shifting rod (pipe) from the centre shifter knob location extended to the tail end of the chassis.
  On the frame structure, the lower side pipes and the width-wise lower pipe behind the cockpit were rectangle tubes, with most of the other frame pipes being round steel tubes in various diameter.  The upper left round pipe was used as the water (the use of anti-freeze chemicals was prohibited by most of the race organisers at the time for the danger of making the tarmac slippery) feed pipe for the radiator up front, and the lower right side pipe and a half of the width-wise lower rear cockpit pipe was the return tube.  Likewise, the upper right side pipe was the oil feed to the oil cooler, and the lower left tube was the return.  This frame was mostly made by Arch Motors, carrying 'AM' serial number.
  This configuration was shared with Lotus 22 and other Formula cars of the time, but the combination of a wider and thus larger radiator, wider (and somewhat bulkier) steel frame acting as a cooling device, and the small displacement engines resulted in more than ample cooling capacity.  Atypical of the contemporary racing cars, Lotus 23 models sometimes experienced an over-cooling problem in sprint races, and displayed a very stable water temperature in endurance racing.
caption: Lotus 23B.  The much thicker 3-point roll bar, as opposed to the original thin 2-point, and smoked wind screen are modern additions
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