79,500 horsepower at 79 rpm

8 comments

• doctorevil

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  4 years ago

  Easily found on Google. H = T x RPM/5252. So, T = H x 5252/RPM
  
  So the answer is: 5,285,354 ft/lbs
  
  I thought it more interesting that the second set of numbers in engine nomenclature designates is piston diamater in centimeters, in this case 95cm, which is 37.4 inches. Each cylinder is over 1 yard in diameter.
• gSteph

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  4 years ago

  Thanks, doc. Curious how it's got 11 cylinders, it's a 2-stroke, and the engine family is noted for its compactness and efficiency.
• doctorevil

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  4 years ago

  I was also curious about the 11 cylinders. Most engines I am familiar with have an even number of cylinders, but I will admit to being totally unfamiliar with engines of this size, so maybe it's common in ship engines. The only other engine I can recall with an odd number of cylinders was the 70s era Saab with 3 cylinders. It was also a two stroke as I recall.
• doctorevil

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  4 years ago

  Actually, I think Audi had a 5 cylinder engine for a while, also.
• ATACdawg

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  4 years ago

  As did Peugeot and Volvo (same engine).
  
  Large ship engines rotate so slowly that dynamic balance isn't a big issue, so the odd number of cylinders is more a case of scaling up horsepower by adding cylinders, which doesn't require many new parts.
  
  Also, the odd cylinder is often used for starting and reversing the engine using compressed air.
• goldmongerATL

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  4 years ago

  You just space the cylinders evenly around the crank. In a 4-stroke, you space them out around 720 degrees of rotation. So in a 4 cylinder you have them 180 degrees part. 120 in a 6. 90 degrees in an 8. So in the Audi 5, they were 144 degrees part. A buddy had one. Had to throw away that extra spark plug when doing a tuneup.
• goldmongerATL

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  4 years ago

  Looked up the Ultra long stroke. That monster has a 3 foot wide cylinder and about a 12-13 foot stroke!
• minnow

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  4 years ago

  @dr evil- Several aircraft radial engines have odd number of cylinders. (arranged circularly). The classic DC-3 had 9 cylinders, many prop airliners from the 50's (DC-6, CV240/340/440 had the R2800 with 2 banks of 9 cylinders, 18 total). Some Air Force cargo aircraft had R4360 engine with 4 banks of 7 cylinders, 28 total.