-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
QUOTE: Originally posted by Randy Stahl I think the SD45 got way more bang for the buck than the SD40.. Think about it 600 more horse power from 4 more holes the sd45 is a great drag engine meant to stay in throttle 8. Problem is,, not alot of RR applications require this and when the locomotive is used for less strenuous work , the efficiency goes in the toilet. The SD45 s biggest problem was the long crankshaft that had a bad habit of snapping . I guess that became a regular occurance, I've seen many myself. I think the SD, in SD45 really did stand for special duty.
QUOTE: Originally posted by Randy Stahl I can see wanting to get rid of the turbocharger, with a life expectancy of about 5 years, and a replacement cost not including labor $25,000.00. big expense!!!! If I were running a small RR on a tight budget I would fear all my turbos going at the same time!!!! Randy
QUOTE: Originally posted by M.W. Hemphill Randy, can you recall a SINGLE instance of a 20-645 that had blanked cylinders -- that actually ran? I've heard talk of it, but cannot recall a single example that made it into service. I've never seen one. There was, as I recall, an experiment of using two cylinders (I believe of a C30-7) engine as the air compressor. I never heard anything more about it, which leads me to believe it wasn't successful.
QUOTE: Originally posted by Randy Stahl MK was cutting 20 cyl engines down to 16... I seem to recall the SP running a bunch of them. Randy
QUOTE: Originally posted by Overmod I suspect that the 'long term' effects while substantial may be easy to document. My understanding is that EMD engines with bad power packs are fairly common in service, and often the engine isn't pulled for service until a certain number of them are dead. (Whether or not the engine is pulled immediately for something that isn't an individual-cylinder failure is another matter). Randy, is there any 'preferential' location for powerpacks to go bad? If not, there can't be any good prediction of what the torsional stress in the crank would be, or what the long-term implications of peak stress might entail. It's been my suspicion for some time that dead cylinders were a major contributing factor to some of the crank breakage on the 20-cylinder engines. Other reasons why two-strokes don't make 'twice the power' of a four-stroke: a scavenged engine doesn't have the charge density of a four-stroke with intake valves in the conventional position, given equivalent levels of boost. I can't find the reference to 'bmep', but the effective cylinder pressure on a two-stroke might as well be no higher than boost pressure by the time in the stroke that the scavenge ports begin to be exposed, or you'll start to get gas cutting on the rings, one of the places you'd least want it. Oh, by the way, there are a couple of 24V71s on sale if you want 'em. TA's, too! http://mdeltd.com/product.php?product=Marine%20Engines (Scroll down the page a ways to find them) Nifty looking things; they don't look to me as if they use a pair of 12V71 cranks bolted together, either... There are apparently quite a few yachts that have these things. One wonders, though, how many hours you'd get if you got 1800hp @ 2300 rpm out of them for any length of time <8-O
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