1935 ROLLS-ROYCE 20/25HP FOURSOME DROPHEAD COUPE. Photo Bonhams

Coachwork by Thrupp & Maberly. Chassis no. GAF 81. Engine no. U2B. 3,699cc OHV Inline 6-Cylinder Engine. Single Carburetor. Est. 55-65bhp at 3,000rpm. 4-Speed Manual Transmission. 4-Wheel Leaf Spring Suspension. 4-Wheel Drum Brakes. Estimate US$ 100,000 - 150,000 (€75,000 - 110,000)

*Matching numbers example
*Rare Thrupp & Maberly three-position coachwork
*Older cosmetic restoration
*Extensive factory records
*Well-documented example

THE ROLLS-ROYCE 20/25HP

The 20/25 Rolls Royce, built from 1929 through 1936, became the company's most popular design prior to the Second World War, with some 3,827 examples delivered. The 20/25 succeeded the smaller-displacement 20 hp model. Initially built on a 128.7-inch chassis, the 20/25 was later offered on a "long" chassis of 131.9 inches, which was introduced in 1931. Later 20/25s featured a four-speed fully synchronized gearbox and a centralized chassis lubrication system.

The 20/25 was powered by a 3.7-liter inline, overhead-valve six with a cast-iron block. The engine had a separate aluminum crankcase containing a robust seven-main bearing crankshaft with vibration damper and a detachable cast iron cylinder head. The engine was lubricated by a pressurized system that also fed the rocker shaft and timing gears. Ignition was by independent coil, a centrifugal-advance distributor, and a backup magneto. An engine-driven water pump with fan cooled the engine, and a thermostatically-controlled system opened and closed the radiator shutters as required. Fuel was delivered via one single-jet carburetor. While the 20/25's engine produced an estimated 65 horsepower, Rolls Royce never publicly advertised such numbers, stating only that it was "adequate". In order to ensure reliability, the company carefully ran in every new engine on a dynamometer and kept careful records of each test and every part that went into the chassis. The transmission with its single dry-plate clutch was bolted to the rear of the engine block, with a floor shift installed to the right of the driver's seat. The rear axle was of the full-floating type. Large four-wheel drum brakes were servo-assisted. 

As was standard practice for the period, the completed chassis would be delivered after testing to a coachbuilder selected by the customer from catalog illustrations, where a new body would be either installed from inventory, or constructed and finished to the buyer's specific wishes. 

THE MOTORCAR OFFERED

Chassis number GAF 81 is a late 20/25, built on the longer frame, and fitted with Series F2 engine number U2B. The engine's original dynamometer records, dated November 28, 1934, show it developed 55 bhp at 3000 rpm and 127 foot-pounds of torque at 1750. 

Rolls Royce shipped GAF 81's bare chassis from Crewe to its London agent, Rootes Ltd., on June 19, 1934, where it was placed into stock, awaiting a buyer. Rootes delivered it to London coachbuilder Thrupp and Maberly on December 17, 1934, where a very stylish new "Foursome Drophead Coupe" body was crafted and installed. When the car was finished, it was duly handed over to its new owner, a Mrs. Campbell of 22 Down Street, W1 London, on March 20, 1935. This close-coupled body was designed to carry four or five passengers if required, but usually just two would be on board; the close-coupled body, rear-hinged doors, and long hood on the lengthy frame made a very elegant statement, and must certainly have served Mrs. Campbell well on her travels through the UK and on the Continent. 

GAF 81 appears to have passed through the hands of several British owners in the 1950s before being acquired in London by the consignor, who had it cosmetically restored while still in the UK. Eventually the car came to the United States and in more recent years has been housed in the San Diego area. 

This handsome and unusual Thrupp and Maberly-bodied Rolls-Royce is offered today in a handsome shade of dark blue, with contrasting horizontal brightwork and chromed landau irons. There is a black canvas three-position top and a simple but elegant tan leather interior. A canvas boot covers the top when it is in its lowered position. The paint is in good condition, although some wear is beginning to show, while the interior is described as being in fine condition. The wheels are covered with painted and polished discs in the fashion of the day. 

A striking and important 20/25 by any measure, GAF 81 would make a wonderful addition to any collection of 1930s luxury cars, or a potential candidate for a full Concours restoration.

Bonhams. QUAIL LODGE AUCTION Carmel, Quail Lodge & Golf Club. 15 Aug 2014 11:00 PDT