Trials Cars That Made Their Mark Between The Wars
[In this article G. D. McBanks and James Anderson, M.B.E., F.I.M.T. recall the latter’s Anderson Specials. These advanced cars used many vintage Humber components and the final version had intercoupled rubber and hydraulic suspension, recently reintroduced with detail differences on the Morris 1100, and a flat-eight power unit.—Ed.]
The Humber-engined Anderson Specials were potent vehicles of original design and spectacular performance in sporting events.
They were designed by Mr. James Anderson, M.B.E., F.I.M.T. He had the backing of his co-director brothers and the entire staff of Anderson (Newton Mearns) Ltd., a Renftewshire firm of motor engineers, who, as main dealers for the Rootes Group, still have an interest in Humbers.
The first Anderson Special, built in 1922, had an 8/18 Humber engine, gearbox, axles and steering unit. Because the 8/18 Humber chassis had its frame side members and running-boards all in one piece and was unsuitable for conversion to a sports special, Mr. Anderson had the idea of welding up a chassis and body frame and he adopted a design which we know today as a space frame.
To provide additional urge the 8/18 engine was modified. The crankshaft was carefully balanced. The connecting rods were lightened by drilling and were polished all over. Special pistons were fitted, with about 7 mm. high crowns to increase the standard compression ratio of 4 or 4½ to 1. The induction passage in the cylinder head was bored out, short of breaking into two adjacent stud bolts. The valves themselves were not enlarged, but were lightened. Double valve springs were fitted and the push-rods lightened. The usual polishing of the combustion chambers and ports was carried out. A dog clutch was fitted in the drive to the dynamotor so that it could be disconnected from the driver’s seat for speed work. The engine stood a fantastic amount of ignition advance.
The standard 8/18 Humber had a propeller shaft with fabric disc joints and no centring device; when the discs were new, the standard car could be driven up to 40-50 m.p.h. but it was not long before vibration cut down this speed. Mr. Anderson overcame this this on his special by dividing the propeller shaft into two by installing a bearing mid-way and also by incorporating ball-and-socket centring devices.
The car was fitted with a streamlined torpedo-shaped body, totally enclosed underneath, which had a very low wind resistance and Mr. Anderson recalls a special peculiarity it had of leaving two individual columns of dust behind it when driven fast on a dusty road. The car, which gained many successes in reliability trials, had a top speed of about 70 m.p.h.
In its later days Anderson Special No. 1 was driven in competitions by Mr. Anderson’s brother, after the 8/18 block had been changed for a 9/20 one. After a spectacular collision with another car which emerged from a hidden side road (which demonstrated the structural strength of the space frame), this special was scrapped in 1934.
Anderson Special No. 2 is still in the garage at Newton Mearns. Its chief feature is its remarkable 8-cylinder engine. Originally, when it was built in 1928, it was powered by two Austin Seven engines. These were replaced in 1934 by the present power unit, the basis of which is a pair of modified 1928 9/20 Humber blocks mounted at 180° on a crankcase fabricated from solid drawn-steel tube and sheet steel. One block is reversed so that all the plugs are on top. The 1928 four-throw, two-main-bearing crankshaft is used, with the big-end journals widened to allow two big-end bearings to he mounted side by side. The bearings are lined with cadmium nickel alloy. The somewhat limited bearing surfaces are compensates for by dry-sump lubrication supplying the main and big-end bearings with oil at 80 lb./sq. in. pressure and to the auxiliary drives at 5 lb./sq. in.
One half of the engine fires 1, 2, 4, 3 and the other half 1, 3, 4, 2, number one nearside cylinder firing simultaneously with number two offside, and number two nearside with number one offside.
This engine developed between 70 and 80 b.h.p. at 4,000 r.p.m. with remarkable smoothness and was capable of taking the car up to 85 m.p.h. in effortless fashion. Apart from the smoothness with which it delivered its power it had the remarkably low petrol consumption of 40 to 42 m.p.g. On a Highland Two-Day Trial its average consumption was 33 m.p.g.!
The engine has two inspection covers on the crankcase through which it is possible to withdraw the connecting rods and pistons. Two downdraught S.U. carburetters are fitted, to which the petrol is fed by air-pressure. The sparks are taken care of by a 4-cylinder Bosch twin-spark magneto designed for a 4-cylinder engine with two plugs per cylinder.
The engine is mounted behind the driving seat. Behind a Humber Snipe flywheel there is a fabric universal joint. The clutch is a multi-plate type, running in oil. The gearbox has gears from a 15/40 Humber, with ratios of 4.5, 6, 8 and 14 to I. Clutch, gearbox and differential form a single unit.
Springing is by a transverse spring at the front and reversed ¼-elliptics at the rear, with radius rods to both front and back axles. The car has a wheelbase of 9 ft., a front track of 4 ft. 5½ in., a rear track of 3 ft. 8 in. and weighs .18 cwt.
A disappearing windscreen, a speedometer half-sunk into the top of the bonnet, and headlamps which swing back into recesses in the sides of the bonnet are other novel features of this remarkable car.
Another trials car was built in 1932 by Mr. Anderson from new 9/20 Humber units which had been bought by a friend with the idea of Copying the original Anderson Special. Mr. Anderson bought the parts and used them in a car which he ran for some years. This Anderson Special, which weighed 15 cwt, had rather unorthodox springing. The rear springs and shock-absorbers were entirely enclosed in the sports-type body. The front transverse spring had a vertical radius rod which passed up behind the radiator and was anchored at the top by means of a damper so that it served both as front shock-absorber and front brake torque rod.
The fourth special devised by Mr. Anderson in 1936 was of an even more revolutionary design than No. 2. Its outstanding features were a tubular chassis, a horizontally-opposed 8-cylinder engine, independent suspension on all four wheels and 4-wheel drive.
The suspension was a rubber and hydraulic combination. A piston moving in a cylinder had above and below it suitably proportioned rubber springs consisting of a multitude of rubber rings sandwiched between metal discs. These rings, on compression, behaved as back-to-back cones. The piston was made oil-tight and the area above it was charged with brake fluid from a hydraulic accumulator pressurised by air. Matters were so proportioned that a percentage of the load was taken by the oil under a pressure of approximately 40 lb./sq. in. The car could still be driven even if the oil supply failed. It was possible to control from the driving seat the air pressure in the accumulator. On approaching a trials hill the pressure was raised, with the result that the rubber springs beneath the piston were compressed, thus stiffening the suspension and increasing the ground clearance.
The oil displaced from one suspension unit could transfer to the other on the same axle. This ensured the best possible driving grip on ther oad on rough surfaces. This transfer feature did not increase comfort however, because when both wheels hit a ridge simultaneously the suspension was naturally much stiffer. The car did not roll on bends as might have been expected, due to its low, centre of gravity. Photographs taken of it cornering often show it to be apparently leaning-in slightly. The chassis frame consisted of three straight tubes, also utilised to carry oil and water and to act as an air reservoir for the suspension. The front wheel mounting and drive was largely Citroen 12. The rear wheels were carried on swing axles. All brakes were inboard, with self-wrapping bands operating on Nitralloy-faced drums.
The engine was a slightly modified version of the successful horizontally-opposed 8-cylinder unit designed for No. 2. It had a Laystall crankshaft. The camshafts were driven by duplex roller chains and auxiliary drives were dispensed with by coupling the distributor, tachometer and oil pump direct to the camshafts. This engine was installed below the driver’s seat.
Transmission was through two hydraulically operated clutches to two 4-speed .synchromesh gearboxes mounted front and rear of the engine. Although relatively low-geared, with a 4.9 to 1 top and 18 to 1 bottom gear, this car had a maximum speed of 80 m.p.h. It could be restarted on grass with a 1-in-2 gradient and could be driven through 2 ft. of water!
When 4-wheel drive was banned from trials Mr. Anderson built “an imitation Grand Prix body” on the car and drove it on the road for a year or two, when, to use his own words, “having to be my age,” he took the engine out and presented the rest to the local Rover Scouts … Lucky boys.
The Anderson Specials were the product of advanced thinking and engineering skill of a high order. They merit a niche in the history of between-the-wars Humbers.
Out of town
Judging by letters with which readers. have bombarded us, Town magazine upset some of its readers when it ventured on a motor racing feature last month—a case of out of Town, out of touch? Apparently a T.V. announcement implied that those purchasing the next day’s copy would find therein colour pictures of Ferrari and other racing cars. Such pictures there undoubtedly were but they were in the new American style, in which all sharpness and detail is sacrificed to slur, so that they were the biggest blur ever in action photography. Such pictures are highly unpalatable to motor racing enthusiasts.
Moreover, the normally very readable Town dropped some clangers as well. Early editions claimed that the colour picture on the front cover showed Phil Hill winning the Grand Prix at Spa in a Ferrari, whereas later editions captioned this picture as Rodriguez in the 1,000 km. race at Nurburgring driving a Ferrari—in any case, it was Graham not Phil Hill who won at Spa. This error was perpetuated within, and again the sports Ferrari on the cover was claimed to be the Spa G.P.-winning car, along with a caption. which gave the Lotus 25 fuel injection.—W. B.