Liberty 12 Original or a copy?

leo · 16 February 2002, 06:07 AM

I just saw something which indicated the Liberty 12 engine was a copy of a Rolls Royce Design. Is this so ? And if so, which engine? The 375 HP Eagle?

19 February 2002, 05:24 PM

Don't believe Liberty was RR copy although you can't discount the influence.
BTW- one of its designer's (Hall) is supposed to be a relative of mine. He was also the Hall of Hall-Scott engines.
Another relative was Austin Hall, veteran of the Great War, seminal writer of the Science Fiction genre, 1920's (according to I.Azimov) ,and my great uncle.

Charlie

19 February 2002, 07:17 PM

Dear Leo,
This is the best that I can come up with; it's from Joseph Phelan's HEROES & AEROPLANES OF THE GREAT WAR:
"There were a handful of qualified aero engineers in industry and the government, and it was they who made the one technical contribution to the Allied war effort-- the Liberty engine. Designed, according to legend, in a Washington, D.C., hotel room, the liberty was originally a 300 h.p. V-8 engine when its plans were unvieled before an official committee in the spring of 1917. By summer the first handmade samples had been tested and their horsepower found insufficient. After redesign, the Liberty emerged as a 400 h.p. V-12, which, once the bugs were ironed out, proved to be a fine engine. It was shipped to the front in large numbers in the last few months of the war, and remained in production in the U.S. for several years after the war."
Phelan, unfortunately, is not always the most accurate, so I would take the last sentence, about 'large numbers', with a grain of salt...
BTW, I still haven't forgotten that I 'owe' you a thread, as to why I consider Hawker a superior pilot to MvR.
VBR,
Capt. Lewis

22 February 2002, 01:32 AM

I believe it was the designers intention to incorporate (read copy) any successful design criteria into their product.

SteveD

Dan_San_Abbott · 26 February 2002, 09:43 AM

Leo:
i don't for a minute believe the Liberty was influenced by the Rolls-Royce. What influenced the design was the Hall-Scott A5a engine and the Hall-Scott A-8 V-12 engine that produced 450-500hp that was ready for production on1May 1917, when Hall was called to Washington D.C. on the Liberty engine developement. Inasmuch as it was designed E.J.Hall who was one-half of the Liberty design team. The Hall-Scott A.5 /A.5a design was influenced by the Mercedes engine. As a result of the Liberty 12, the Hall-Scott A-8 died on the vines.
Blue skies,
Dan-San