Letters from Readers, July 1946

May I be permitted, through the hospitality of your correspondence columns, to congratulate “W.B.” on his excellent article, “The Real Hispano-Suiza,” which has served to illumine my own, and doubtless other readers’, ignorance of early Hispano-Suizas? if, moreover, I may make one small correction, I would mention the fact that I am informed, on tolerably good authority, that E. K. H. Karslake’s car which you say existed in the ‘thirties, was actually broken up (or, to be more accurate, fell to pieces!) as long ago as 1928. It then needed extensive repairs to its clutch, universal joints, back axle and steering-gear, which in those days could only be carried out at a high cost, while the car would have remained without any market value after they had been effected. The subsequent change in the situation in this regard is almost entirely due to the educative efforts of Motor Sport, although I notice that of very recent years other journals have tended to pay your paper the sincerest form of flattery in the matter.

It is perhaps of interest to note that, according to “Le Catalogue des Catalogues,” the manufacture of the 4-cylinder 100 by 150 mm., Type 30T, was continued at Barcelona until 1920, as was that of two other models, both introduced in 1914, Type 8, 70 by 120 mm., and Type 16T, 85 by 130 mm. I drove one of the last-mentioned type, which was usually known in this country as the “Barcelona” model, about 20 years ago. Its date was supposed to be 1916, and I remember that its smaller capacity (2,940 c.c. as against 3,614 c.c.) and relatively short stroke made it seem disappointing in spite of its overhead camshaft, when compared with the 80 by 180 mm. T-head “Alfonso” model. I should be interested to know if any reader has had experience of the 1,843-c.c. Type 8, or of any cars of the marque manufactured, as mentioned by “W.B.,” in Switzerland.

With regard to performance, I find that in an advertisement in The Autocar of August 10th, 1912, a maximum speed of 77 m.p.h. is claimed for the “Alfonso III” model and 54 m.p.h. for the 80 by 130 mm. model. Subject to “W.B.’s” correction, I should have thought that the former claim was optimistic by about 5-10 m.p.h.; but the claim made for the 80 by 130 mm. Type 15T certainly does not appear exaggerated.

During the Kaiser war the Hispano-Suiza aero engine manufactured at the French works was almost as outstanding as were the Rolls-Royce engines in the Hitler war. The announcement in 1919 of the 37 h.p. (32 C.V.) 100 by 140 mm. 6-cylinder car, Type H6B1, was therefore as eagerly awaited as was that of the “Silver Wraith” in 1946. It is not my purpose to draw any invidious comparisons between these two designs, which are separated by more than a quarter of a century, or to try to judge as to which more completely fulfilled the hopes of motoring enthusiasts. But it is certain that Type H6B1 was a very fine motor car, which, however, did not satisfy the aspirations of its makers when they entered for the Monza races in 1923. In consequence they produced a special engine of 105 by 140 mm. (to be followed the next year by the better known 110 by 140 mm. Type H6C). The 1923 model was not, I think, produced in series, nor did it actually run at Monza; but one car of this type was brought to England by Count Zborowski and was afterwards very well known to me. Fitted with a narrow 2-seater body, and flared wings and short streamlined tail, it was, I think, the prettiest car I have ever seen. I lost sight of it some years ago, but I have recently heard that it was seen in Devonshire shortly before the war, having at that time a broken second-speed pinion. I should be most grateful if any reader could tell me of its present whereabouts.
I am, Yours, etc.,

In his article on induction efficiency, Commander Featherstone objects to a manifold having sharp 90° turns and prefers slow, easy bends.

May I point out that manifolds having right-angle turns, sharp junctions and, more important, square sections are made that way because they are, in fact, better than the smooth-flowing circular-section type.

The latter sort cause a difference in speed of the gas between the inner and outer radius on a curved bend resulting in petrol being deposited on the inside by the slower-moving mixture.

This argument may raise some controversy. I know that several manufacturers, including Rolls-Royce, Ltd., use the design of manifold that Commander Featherstone recommends, but many designs, particularly of high-performance engines, have the apparently inefficient square type.

There are, of course, many more factors involved in induction manifold design than the one I have mentioned, a hot spot can be of definite advantage, particularly if situated directly opposite to the intake from the carburetter.
I am, Yours, etc.,
Ronald E. Passmore (Lt.).
North Cheam.

Mr. Ward and Mr. Parker have disagreed with my conclusions as to the effects of supercharging the Gregoire. It appears to me that if the breathing of an engine is artificially restricted, as by small valves, no amount of supercharging is going to remove that restriction, and the gain in horse-power can only be proportional to the amount of boost applied, e.g., rather less than 50 per cent. for a 7 lb./sq. in. pressure.

I say this quite as a tyro and am entirely subject to correction.
I am, Yours, etc.,
Cecil Clutton.
London, W.11.