At last—the truth about the original twin cam straight-eight supercharged Triumph Dolomite

by its creator, Donald Healey
[Last April, in “Rumblings”, we recalled the sensational 2-litre Triumph Dolomite, almost a direct copy of the then current 2.3-litre Alfa Romeo, which Donald Healey evolved in 1934 for the Triumpg Motor Co. Ltd. How this crib of the famous Italian sports car was possible (did Healey steal the drawings, dissect a car?) and what Alfa Romeo thought about it has remained a tantalising secret for 38 years. Now 74-year-old Donald Healey, on the eve of the release of the Jensen-Healey, which follows the original Dolomite in having an exciting engine—a sixteen-valve twin-cam—tells for the first time the true story of Triumph’s short-lived straight eight, in this exclusive Motor Sport article. — Ed.]

In 1934, after the great success of the Triumph cars in the Alpine Trial, Sir Claude Holbrook, Chairman of the Triumph Company, Tommy Wisdom and myself were deploring the lack of a good British sports car able to compete with the Continental cars of that date. Tommy was then one of our top sports-car drivers at Brooklands and in rallies and the Alpine Trial. He suggested that we built a car similar to the then-most-successful racing car, the 2.3-litre Alfa Romeo. Sir Claude agreed and I was given immediately a very tight budget to build such a car in the least possible time. That budget would not have been enough to develop a scooter, today! To design and develop an engine of this type, with our limited knowledge of such a machine, would be a big undertaking, although we made the best motorcycle engine of the day, and had developed a completely new range of engines for the current Triumph cars.

Our production engines had to be designed and produced to normal time-schedules, but this new job had to be done quickly, and as economically as possible. I decided to get an Alfa Romeo and make a design-study of the engine, and to keep as close to its design as possible.

I have been accused or being a copyist, but it is the general practice of all car producers to carefully study competitors’ products. One of the most famous cars in the world had its present engine developed from a well-known American engine and was originally a very close copy. [Which one does he mean, I wonder ?! — Ed.]

So I purchased an Alfa Romeo racing car, being lucky enough to be able to buy the 2.3-litre so successfully raced by Lord Essendon, then the Hon. Brian Lewis. I also visited Italy and discussed our intentions with Alfa’s Chief Engineer, the famous Signor Jano. Alfa Romeo were very pleased and honoured that a Company as famous as Triumph had decided to follow their design—we even discussed the possibility of calling the car a Triumph-Alfa. They were very interested in our up-to-date range of motorcycles and considered the possibility of making one of them in Italy. Signor Jano was very helpful. But we decided not to join up the names in any way.

I was fortunate in that we had a first-class engine drawing office and probably the best tool-room in Coventry. With much overtime working and a lot of enthusiasm we had an engine running in under six months. It was made completely by “knife and fork” methods; even the Roots blower rotors were hand-contoured. To our delight the engine gave over 120 b.h.p, without any tuning; this was later improved to 140 b.h.p. The beautiful block and head castings were made by High Duty Alloys but we made every other part ourselves, I had a discussion with Mr. Robotham, the Chief Engineer of Rolls-Royce, on the new bearing metal just discovered, lead-bronze, but unfortunately our crankshaft was not hard enough and we badly scored and ruined the two halves of the crankshaft, probably representing 500 hours of skilled craftsmens work. So we changed back to white-metal-lined shells and had no further trouble. A retrograde step probably, as the bearings were very narrow and theoretically very overloaded; if we had had time to further develop the crankshaft for lead-bronze bearings we could have raised the b.m.e.p. considerably. But we could not afford to be pioneers.

The chassis presented no difficulties. A normal gearbox could not be found to cope with the power we had—but Siddeley had done a lot of work on developing a racing epicyclic pre-selector box for ERA. I decided to use this and never experienced any kind of trouble. Alfa Romeo were then using aluminium brake drums of very large diameter and very narrow shoes and, against the recommendation or Gordon Parnell of Lockheed’s, I had them made. Parnell had pointed out that the rubbing speed was far too high for the linings then available and they were never a success. Later on we changed to normal-size brakes in cast-iron drums, which proved as good as could be got in those days. We used springs with an extra large number of leaves to increase the neutral damping and these, coupled with Hartford dampers, gave an excellent hard ride, as was then thought desirable on a fast car. Later I learnt, during four days and nights on a Monte Carlo Rally, how hard they really were! We had a bit of trouble with frothing of the oil in the pretty ribbed tank fitted between the front dumb-irons and for road and rally use reverted to a wet sump. The Roots blower was the same size as that on the 2.3 Alfa so we had a little more boost on our smaller 2-litre engine. Beyond the noise, this never gave any trouble with the SU carburetter used.

The Dolomite’s body was quite original. It was styled by the stylist of all the Triumph cars, Walter Belgrave, was made entirely in our coachwork factory, and was considered by experts to be very beautiful.

On the road the car did all we expected. The testing was all done by Jack Ridley and myself. Tommy was the first racing driver to try it and his write-up described the car as excellent in every respect. We did a lot of testing at Brooklands but never achieved the lap speed of 120 m.p.h. which we hoped for—still, it got very close to this and, considering a rather wide touring body, we were quite pleased. One incident during testing—when doing something over 100 m.p.h. on the London road the car and I were spotted by a PC and reported to Coventry Police for dangerous driving. Fortunately my passenger was the Hon. Cyril Siddeley, the then-Lord Lieut. of Warwickshire, and his word refuted the dangerous driving charge. . . .

Having a car with a such superior performance I thought, here was a chance to repeat my Monte Carlo Rally win of 1931. Starting from Umea in Northern Sweden in the 1935 Rally, I demolished the front end of car No. 1 in a collision with a train. From the remains of this built a car for the next Monte Carlo Rally but this time I ran without the blower and managed to finish eighth.

During that year the Triumph Company got into financial difficulties. The motorcycle business was sold and the Dolomite programme was cancelled completely and the name used on a production car we were introducing. [I remember road-testing the latter for Motor Sport at the time. Ed.]

During my time with the Triumph Co. I knew a very enthusiastic schoolboy at Eton, who wished to become a racing driver. I built him a special six-cylinder Triumph Southern Cross for the Alpine Trial, in.which he did very well. He was the later-to-become famous Tony Rolt who, with Duncan Hamilton, won Le Mans in a Jaguar and finished so well up in a Nash-Healey. The remaining Dolomite and bits enough to build another engine were sold to him in about 1936. I do not remember what became of them; I had lost interest.

People have made rude remarks about my copy of the Alfa Romeo and have suggested that Alfa threatened Triumph with legal action. etc.—I can categorically deny this; actually they were extremely helpful, as I previously have mentioned.