Looking in on the Healey
The Editor and Cecil Clutton visit the factory where one of Britain’s most outstanding High-Performance Cars is in production
From its inception the 2.4-litre Healey has aroused widespread interest and a visit to the factory in Warwick to inspect it was high-priority on the Editorial agenda. When the Editor made this journey with Cecil Clutton, early last month; he had not seen actual performance figures relating to the car, but on his arrival Mr. James Watt, the Sales Director, was able to greet us with the news that the saloon Healey had been timed by the Automobile Club of Milano to do 104.65 m.p.h. over a flying mile on the Milan-Como Autostrada, and to have clocked 17.8 sec. for the standing start 1/4-mile. It had also covered a kilometre at 106.56 m.p.h. These figures, in respect of which the Italian Club has issued a Certificate covering the deeds of car No. NX 199, engine number M 502, chassis number A 1502, were a fitting prelude to our inspection, because these performances by a closed car of 2.4 litres capacity are, frankly, momentous. The aerodynamic bodywork clearly pays big dividends, especially as the fuel consumption came out at well over 30 m.p.g. at 70 m.p.h. cruising. Donald Healey has convincingly realised one of his ambitions, to market a production saloon car able to exceed 100 m.p.h. That he has done this with a moderately-tuned, four-cylinder engine of but 2.4 litres capacity is all the more to his credit.
Mr. Watt told us of the origin of the Healey. Donald Healey, noted for his exploits with Triumph and Invicta cars, particularly in the Monte Carlo Rally, felt that it was about time Britain competed properly with Continental high-performance cars. So he set about evolving the Healey and each problem in respect of design was approached by considering first how much given components would weigh, afterwards, how much they would cost. His ideal was to build a car weighing just a ton and then to give it a 100-b.h.p. engine. He hasn’t quite realised that ideal, but, in view of the performance figures quoted above, there is no need to carp about that! Actually, the “Big Four Riley engine selected gives 104 b.h.p. at 4,500 r.p.m. (it will run up to 5,000 r.p.m.), and the complete saloon weighs 22 1/2 cwt. unladen.
To revert to the prototype car, this commenced to take form in 1942 and the completed components were assembled in about a fortnight by Donald Healey in person, working under extremely trying conditions, partly in the open amongst cement-mixers dumped outside a friendly factory. That was in 1943-45, and Watt came home from India to see the chassis, only to be posted abroad again before he could help with it — he was a S/Ldr. in Coastal Command during the war and associated with Hudsons and, later, heavier metal, such as the York.
All that had to be done to the Riley engine to make it suitable for Healey’s purpose was to replace the down-draught carburetter with two S.U.s and fit an easy-flow exhaust system. The latter gave some five additional b.h.p. We understand that each engine is supplied by Rileys with a power curve, and that they use the same modifications for the engine in the new 90-h.p. 2 1/2-litre Riley car. The Healey’s compression-ratio is 6.5 to 1 but this may be increased to 6.8 to 1 when pump fuel improves in quality. The engine in the prototype has apparently done 100,000 miles without mishap. Sam Clutton asked about piston velocity in relation to road-speed, in view of the 120-mm. stroke, and we discovered that 2,500 f.p..m. at the pistons equals 69 m.p.h., although Watt said that going up to the Edinburgh Cavalcade, for instance, he held 75 m.p.h. without concern.
It has been said that “All you need know about the radiator of the Healey is that it is a “Serck,” but we propose to add to this — an interesting innovation is the use of pressure cooling. The release-valve in the overflow pipe of the sealed system is set to open at 15 lb./sq. in., quite a high pressure. This puts the boiling point up to 228 1/2°F., and it is possible to use bottom gear for appreciable periods up long Continental hill-climbs without fear of overheating. Water is the coolant at present, but glycol may be used later, still further raising the boiling point. The filler cap is sealed with a rubber washer, enabling the radiator to be topped-up in the normal way.
The chassis frame is made of 18 gauge sheet steel of “top-hat ” section, with a closing plate at the base. The interior of the “top-hat ” section is rust-proofed and the whole frame is given a corrosion-resisting coating of a tar-like substance by Dockers. The side-members are straight, because curves weaken a structure, and the photograph shows the construction. A very rigid chassis results, yet one that is astonishingly light. Either end can be picked up with ease and, with all fittings, body brackets, engine and spring-mountings, rear platform, etc., but less tank, the weight is a mere 160 lb. So stiff is this chassis that the jack lifts centrally and keep-cables hold the front wheels clear of the ground as the suspension goes slack. Very flexible i.f.s. in the modern manner was decided upon and a fine trailing arm layout was designed. For this, and much of the rest of the chassis, A. C. Sampietro, who was with Railton when Cobb’s 370 m.p.h. car was designed, was largely responsible. The suspension arms look heavy: actually they are of R.R.56 alloy and very light. Their length makes possible a wheel deflexion of 7 1/2in. while employing normal coil springs in the suspension units. These springs work in conjunction with built-in hydraulic dampers. The trailing arms pivot on needle-roller bearings carried in boxes on the chassis frame. These bearings are packed with grease on assembly and require a mere couple of strokes with a grease-gun every 15,000 miles. At the rear, in the interests of weight-reduction, a normal axle is used, with coil-spring suspension of lower periodicity than at the front, the wheel movement here being 3 1/2 in. A Panhard rod locates the axle and two stays, also adopted for the 90-h.p. Riley, run forward from the extremities of the axle to the transmission torque-tube, to steady the axle under hard application of the brakes.
The steering layout is most ingenious, the motion from the non-reaction steering box to the wheels being via a swivelling plate and link-members. This plate is attached beneath the chassis on a light-alloy mount lug and it pivots on ball and roller bearings. These bearings are packed with grease to combat condensation, but no further lubrication is required during the life. of the car. While on this subject, there are twelve lubrication points in all on the steering and i.f.s. assembly, and the swivel-pins have oil reservoirs at the base which require replenishment every 1,000 miles. Rubber covers keep the lubricant where it should be on the steering joints. The steering plate provides proper Ackerman angles at the wheels, by reason of the points at which the links are attached to it, and the whole steering gear has been designed expressly to eliminate kick-back at the steering wheel. The column rake is adjustable and if clients require further adjustment they can either be individually measured for their cars, or dished spring-wheels can be fitted. The castor-action is easily adjusted through 3°. but cars are sent out with neutral castor.
The gearbox is the normal Riley unit, but by using a 3.5-to-1 axle rat io indirects of 4.96. 7.54 and 12.76 to 1 are obtained, light-weight construction and streamlined bodywork permitting these high ratios in spite of the engine’s 2.443 c.c. The arrangement was finally decided upon in preference to an over-drive top. At 1,000 r.p.m. in top gear the engine is doing 22 m.p.h.
The wheels are bolt-on discs carrying 5.75 by 15-in. tyres. The smallest possible wheels were chosen, to reduce unsprung weight, and when Clutton asked if small wheels did not drop into holes in the road. Watt said they did, but look at the spring deflections that looked after your comfort in a Healey. We queried why centre-lock hubs are not used and were told that a check had been taken on comparative weights. Apparently the saving in unsprung weight on four wheels by using bolt-on wheels is 25 lb., but, quite honestly, Watt said that the question of cost and availability of supplies would have decided that point anyway.
The brakes are Lockheed hydraulic and because of the small wheels the drums are fairly small-10 in. dia. at the front and 11 in. dia. at the rear. This has been found satisfactory, and the difference in drum size is intentional, to put 68 per cent. of the braking force on the front of the car as, from the viewpoint of comfortable riding, there is more weight aft than forward. The front drums contain two leading-shoes, but the rear brakes have normal shoe mounting, to give effective braking in reverse.
Throughout the chassis one notices the care given to detail work. The pedals are in R.R.56 and extremely light, and they are mounted on “Oilite” bushes, while the linkage to brake-cylinder and clutch-arm incorporates these bushes and proper pins throughout. The propeller shaft has double Hardy-Spicer universals, more nearly to obtain true constant-velocity joints, and the engine mounting angle humours the transmission line. The universal-joint trunnions and Panhard-rod joint are rubber bushed and the torque tube which encloses the rear end of the propellershaft is located on a rubber-mounted anchorage on the chassis. Simmonds lock-nuts are used throughout and where a component is attached to the side-members a rod is run across the chassis and the joints welded. The throttle-pedal is of piston type, conveying motion through an enclosed push-cable. Two Burgess silencers are mounted in tandem on the near side of the frame, a very nice exhaust manifold and steel pipe leading into them, while, again to reduce weight, the tail-pipe is of three per cent. magnesium alloy.
The aerodynamic bodies for the Healey were the subject of wind-tunnel tests with ith scale models, in the wind-tunnel of Armstrong-Whitworth Ltd. Much experimentation was engaged in before the final form was settled. The saloon has ample head room and a large screen area. The wind-up windows are Perspex, treated against abrasion, as such windows were in R.A.F. aircraft. The rigid, streamlined wings weigh 8 1/2 lb. each. Very satisfactory bucket seats, leather upholstered, have been evolved, and the body width of both models is approximately 3 ft. 8 in. at the front seat. The bodies are panelled in magnesium alloy, and the bonnet hinges up from the rear to give very good accessibility. The saloon costs £1,597 19s. 3d. with purchase tax, the roadster £1,566 0s. 7d. The chassis comes out at £900 exclusive of tax.
At present orders are flowing in, many for export, but delivery takes some time, as delay occurs unavoidably at the coachbuilders. However, some 30 persons are turning out three chassis a week and a few of these can be delivered immediately to anyone wishing to market a special-bodied car or to have a body built privately. Endowed with a shell-body, which would not take so long to build, the Healey would have a staggering performance and many people will doubtless be interested to pursue this line of thought. The firm does not intend to race, but will give every encouragement to private entrants in events such as the T.T.
Whichever way you look at it, the over-100 m.p.h. maximum of the Healey, coupled with tremendous acceleration (it goes from rest to 60 m.p.h. in about 12 1/2 sec.) is a most outstanding show by a 2.4-litre saloon basically priced at £1,250 today. It qualifies our enthusiastic remarks as to the quality and capabilities of present British high-performance cars with which we prefaced the “Show”-supplement in Motor Sport last November. And it fully justifies aerodynamic bodywork. After we had thus critically examined this breath-taking newcomer, Watt produced a roadster for an excursion around Warwick and we hand over to Cecil Clutton, the well-known car critic, for a report on the trip.