Attached herewith, you will find my expression of apology to Mr. W. O. Bentley, which applies to my two (2) articles; one printed in 1964 and the other one of recent date, on which you commented in your January issue.
May I say that I enjoyed the “hand-off-attitude” of your remarks, for which I am very grateful.
I hold no brief against Mr. Bentley, and seeing the explanation he gave the editor of our magazine, dated February 8th, 1971, as most conclusive, I see no reason to pursue the subject. I hope he can give us more information, for historical purposes on the development work of the BR1 and BR 2 aircraft engine.
Regarding the “Airplane Engine Encyclopedia”, edited by Glenn D. Angle in 1921, Bentley is wrong in relegating this as merely a catalogue of aircraft engines. I am submitting herewith, a photostat of what he has to say about the Bentley and Clerget engines, which, I believe, is quite interesting.
Mr. Angle, who is no longer with us, was a most erudite authority on aircraft engines. His text book and collated information on aircraft engines, starting with the Abadal to Zeitlin (variable stroke rotary), a total of 525 pages of detailed information. (I have a complete story on the latter engine, in the event you are interested.)
Personally, I feel that this entire Bentley matter is a tempest in a tea pot and I am a bit surprised at his sensitivity. All I am trying to do is to give credit, where credit is due and if I am wrong, I am the first one to accept corrections, which, I believe in this case are legitimate.
I am puzzled with his claim that he was able to cast aluminium fins on to steel barrels. This has been tried many times, both on air cooled and water cooled engines and was abandoned because of the high expansion of the aluminium, as compared to steel, which created clearances and eventual seepage, destroying the heat transfer between the jacket and the barrel. This was the basic trouble with the Marmon Model 34 and the Hispano 6 Hb, until such time when they converted to wet sleeve engines.
As I have intimately been associated with the early development of aircraft engines, immediately after World War I, I shall be indebted to you if you can throw any light on the subject. I can not tell you how much I enjoy reading the vintage and veteran pieces in your magazine. Please keep up the good work.
Alec Ulmann, President.
New York, USA.