W.O. Bentley replies to Alec Ulmann

Sir,
In the course of a long and full life, I do not think that I have ever read such a malicious, biased and wholly inaccurate collection of innuendo and mis-information as that published in “The Bulb Horn” issue of Sept./Oct., 1970, under the name of A. Ulmann.

I am, moreover, astonished that a publication of such standing should print such material. However, with a view to putting the record straight for your readers who, I am sure, are as bewildered as I am by this attack, I have endeavoured to provide detailed and factual answers, as under:

(1) Regarding the comment on the short time factor between the signing of the Armistice in November, 1918, and the announcement of the first experimental Bentley late in 1919.

(a) A very great deal of discussion had already taken place between F. T. Burgess and myself. Our ideas were thus clearly formulated, so much so that within two months of the Armistice, as I have already recorded in my books, we sat down with Harry Varley and concentrated on nine months’ intensive work on the drawings of the design. Burgess, whom I had known earlier in racing, was head designer at Humbers during the war and a draughtsman supreme who could produce accurate drawings at quite incredible speed. Perhaps we were fortunate but the fact that we were able to produce the experimental car and engine in two years represented no great magic; it was the outcome of real, hard slogging by a small but devoted team, which had to be done against the clock since we had so little money.

(2) Regarding the alleged resemblance of engine layout between the Bentley and the four-cylinder, overhead camshaft Hispano Suiza engine, designed by Marc Birkigt in 1919 and marketed in Europe, including England, prior to the war and also the sighting by Ulmann of an example of this car in Spain during last summer.

(a) Ulmann was fortunate indeed to have seen such a machine last year; certainly more fortunate than I. I have never set eyes on this particular car or engine in my life, nor have I ever seen any drawings. Thus in no way could the Hispano Suiza have influenced the design of the 3-litre Bentley. I owe most in that respect to the racing car designs of Mercedes and Peugeot.

(3) Regarding the comment “…W.O. and his pre-and-during World War I activity which, in addition to his sales efforts on behalf of the French DFP car, for which he was British concessionaire…

(a) It is a matter of record and therefore of indisputable fact that the outbreak of World War I, killed overnight the efforts of my brother and I to market DFP cars; he joined the Armed Forces immediately and I followed a few months later. This, I think, disposes of the ridiculous suggestion that I engaged in sales efforts during the war.

(4) Regarding the allegation that the BR1 engine was based on the Clerget, and the comment on the use of the aluminium piston.

(a) In support of his preposterous theory Ulmann quotes from Glenn D. Angle’s “Aircraft Engine Encyclopedia,” 1921. Reference to this publication, of which I have a copy, reveals it to be little more than a catalogue of engines designed during the war but not necessarily put into production, and based upon brief statistical information supplied by the numerous manufacturing companies. Ulmann states that “the Bentley BR2 differs considerably from the prototype BR1…” This is incorrect. The BR2 employed the same basic design but was merely a larger engine.

He also makes much of the table of data, purporting to compare the Bentley BR1 and the Clerget 9F. Once again he has his facts wrong. The highest power Clerget produced during the war was of 130 h.p. The Clerget 9F, as shown in the table, never went into production.

As I have recorded in my books, the idea to use the aluminium piston came to me in 1913 while visiting the DFP factory near Paris. At my suggestion a few experimental sets—12% copper and 88% aluminium—were cast. These pistons were not only satisfactory but enabled us to obtain much greater power from the engine of this car.

When war broke out I took the aluminium pistons to the Admiralty and, on their instructions, succeeded immediately in persuading Rolls-Royce and Sunbeam to incorporate them in their aero engines and, of course, used them later in my BR1 and BR2 engines which were built at the Humber factory at Coventry and elsewhere.

Regarding the suggestion that I copied the Clerget engine, this clearly originated from those who glanced only at the cam mechanism—the only similar feature—and were incapable of differentiating. The crank-case, crankshaft, method of securing the cylinders as well as their heads on the BR1, were all fundamentally different from the Clerget.

It is perhaps worth recalling that one of the main reasons why I was assigned to work on the Clerget engine at the Gwynne factory at Chiswick, where they were turning out these engines for Sopwiths and Nieuports, was the unreliability of the engine in its existing form. This unreliability was due to the “obturator” piston ring, the life of which was short at best but which often failed after a few hours, causing the engine to seize. Due to this failure, far too many pilots were being lost. The trouble was due mainly to the distortion through heat of the cylinders which were of very thin wall section. I overcame this difficulty by using aluminium with a liner for the barrel of the cylinder; this equalised the temperature in the cylinders and allowed us to use ordinary cast iron pistons, thus greatly improving the reliability of the engine.

It is also not inappropriate, in this context, to state that, had there been the slightest suggestion of my copying the design of any other engine, the facts would undoubtedly have been exposed to the full and searching glare of the Royal Commission on Awards, by which I was invited after the war to make a claim in respect of my BR1 and BR2 engines, and which awarded me a sum of money in recognition of this work. No such allegation was ever made which, I suggest, is absolutely conclusive. Moreover, as a serving officer, I had regarded this work as part of my war effort and had expected no financial reward.

It is my view that UImann defeats his case, if indeed he has a case, and makes himself ridiculous by presenting such a hotch-potch of unsubstantial and ill-considered nonsense. Moreover, never having met him, I am more than ever mystified as to the purpose of his campaign of calumny and denigration concerning events that took place more than 50 years ago. Is it relevant to question Ulmann’s qualifications to be judge and jury—what has he ever designed or produced?

Whatever the answers, I trust that he is able to call upon the services of a good libel lawyer. At this rate he is going to need one.

Perhaps, when he has read the foregoing and realised how unwarranted and inaccurate his charges are, he will have the courtesy to send me a written apology.

W.O. Bentley.
Shamley Green.
[Did you, Mr. Ulmann?—Ed.]