| That's a good question for discussion. I would tend to believe that due to the vast experience Rolls-Royce had with aero engines before the Merlin and the very nature of the firm itself, the early Merlin was probably a better piece of work than the early Allison was. That's not to say early Merlins were not without trouble of course. Allison was started as an engineering firm that specialized in making parts for racing cars (they were located right down the street from the Indianapolis Motor Speedway) but also did quite a business overhauling WWI Liberty aircraft engines for the Army Air Corps. That side business eventually eclipsed the racing car business, and the origins of the V-1710 were in an experimental Zepplin engine Allison was developing for the U.S. Navy. So, Allison was not without some experience before the V-1710. During the course of the war, many improvments were made to both the Merlin and the Allison, some to increase performance, some to make for more efficient/more precise manufacture. When Packard was licensed to produce the Merlin, they made several improvents to aid in manufacture, possibly the result of Packard's more extensive background in mass production as compared to Rolls-Royce. By the end of the war, both were developed into very high performance, very high quality engines, facts made all the more amazing when one takes into account the numbers produced. Having seen the insides of both the Merlin and the Allison, I would say the Merlin was a more 'elegant' design, and leave it at that! One finanl note: when the R.A.F captured a more-or-less intact Me. 109, rumor has it the Messerschmitt's engine was carted off to Rolls-Royce for examination. They couldn't figure out how Daimler could machine the crankshaft so precisely...... | 
Linear Mode
