QUOTE: Originally posted by BigJim Randy, I'm sorry, but I think you are wrong on this one. Since this engine is obviously working and air being blown into the air box then into the cylinders and out the exhaust, I find it would be hard to take place.
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QUOTE: Originally posted by Randy Stahl QUOTE: Originally posted by BigJim "This one has an airbox fire going" You're going to have a hard time convincing me of that! Go on
QUOTE: Originally posted by BigJim "This one has an airbox fire going" You're going to have a hard time convincing me of that!
QUOTE: Originally posted by jamison1 QUOTE: Originally posted by coborn35 Man, the Alcos did it nice! Yes, they did!![:D]
QUOTE: Originally posted by coborn35 Man, the Alcos did it nice!
QUOTE: Originally posted by SP9033 Well, All I got to say is, if the seal failure is on the intake side of the turbo bearing, we get a great stack fire. A hung injector just will not produce that fine fire, nore will bad injector timing for whatever the reason. Yep, now I remember a good stack fire, the engine was sucking lube oil though the turbo! BEEN THERE, SEEN THAT, and BOUGHT THE TEE-SHRIT! Jim
QUOTE: Originally posted by SP9033 QUOTE: Originally posted by Sterling1 I believe I asked that same question a while ago (for GE locos); Randy told me that the fuel return line from the turbo is not really well connected and so some fuel gets burned, and shoots out. Matt Matt, Why would you say something like that, Randy never mentioned a fuel line connected to the Turbo, mostly cause he knows that there's no such line. And just what is your motovation here, it an't enlightenment! GO POUND SAND FELLOW! Matt must be our next choice for President of the USA. Another NO-Nothing! That's just great, the working class loses for another 25 years!
QUOTE: Originally posted by Sterling1 I believe I asked that same question a while ago (for GE locos); Randy told me that the fuel return line from the turbo is not really well connected and so some fuel gets burned, and shoots out. Matt
Originally posted by Overmod Some little points that Randy might confirm in better detail: Your basic EMDs, on the other hand, are using the turbo to pressurize the crankcase... I'm a little slow here...So for my benefit lets consider GE's locomotive prime movers 4 stroke diesels engines and EMD's locomotive prime movers a 2 stroke diesel engine(which was the rule, to about 4 or 5 years ago). A turbo uses exhaust gases to drive a compressor (the turbo) that compresses air so that more oxygen reaches the combustion chamber of whatever type of diesel. The compressor/turbo has two main inlets and outlets. The drive inlet and outlet of a turbo/compressor is driven by the engines exhaust gases. When the diesel engine exhausts through a port or valve to the exhaust manifold it spins a compressor blade in the turbo. Inlet for the turbo from exhaust is small, outlet of the turbo is large. This exhaust driven compressor blade in the turbo compresses the incoming air so the engine can burn more fuel, thus creating more horsepower. A turbo on either a 2 or 4 stroke diesel has little or no affect on pressures to the crankcase in a simple understanding. Flow of the air is exactly reverse from the exhaust. Inlet air is carried from a large hole and pushed through a small hole. This turbine blade in the turbo/compressor, rotates very fast, so to make sure this doesn't overheat it is lubricated via a wet bearing, oil coming from the engines lube oil. If the seal fails on the exhaust side, a person calls a crew to clean oil off of stuff like Randy states. If the seal fails on the inlet side, a nice stack fire happens. Gosh, Mr Smart, my high school shop teacher, thanks for the basics, you let me figure this out through writing it out. Randy, its apparent you have never seen a turbo seal failure on the intake side! Now, I remember watching a turbo fire. Its just like the GE stack fires pictured recently, these not happening in EMD's, so it must be a design flaw with the GE's! Jim Bryant - Lawton, NV MP 236 Reply Edit Overmod Member sinceSeptember 2003 21,669 posts Posted by Overmod on Wednesday, March 30, 2005 12:09 PM Some little points that Randy might confirm in better detail: In order for a stack fire to occur, you have to have two things -- just one of these things will cause interesting results, but not a fire: Excessive fuel or soot in the exhaust-gas stream, sufficient to support combustion, and A source of ignition -- something that is above the transition temperature for the reaction between fuel and oxygen at the conditions in the exhaust stream. If you have the former, but not the latter, you will either see the famous blue smoke from revving FM OPs, or the voluminous clouds of inky black smoke seen in some pix of GE units -- where was that famous picture of a "sick UP GE" a few weeks ago? That was essentially a stack fire without ignition... As mentioned in the old MILW threads... that blue FM smoke will ignite nicely into plumes if there's a hot source of some kind, including chunks of carbon, etc. that act as 'flameholders', But absent that, you'd be surprised at how much unburned fuel can be volatilized into thick, stinking clouds without ignition... but will produce enormous WHUMPs of flame if even a tiny source lights them off. (I've seen it firsthand in the Hamptons with friends trying to speed up the lighting of charcoal fires by spritzing lots of lighter fluid on relatively cold coals...) You can have ignition hotspots in GEs all the time -- remember the flame that licks out of U34CH stacks on hard acceleration? Part of that is residual carbon, not burned during the power stroke, that is still glowing and reacting with oxygen a foot or more above the exhaust stack outlet -- you can easily understand that it is at least that hot back down the exhaust tract, and that there are characteristics in the engine that allow EGTs to reach that level. Blow turbocharger oil out a leaking seal into that exhaust gas, which effectively carburetes the oil, or into the intake tract where it effectively overfuels the cylinder (remember this is a four-stroke engine family) and you shouldn't be surprised if your excessive black carbon flashes more conveniently. Doesn't help if the leaking turbo seal either reduces expected boost pressure or effectively drops it to "normally-aspirated" levels. Your basic EMDs, on the other hand, are using the turbo to pressurize the crankcase. Excess oil or fuel here are somewhat more likely to produce crankcase explosions than fires out the stack; the purge air is likely to drop exhaust temps well below what would be expected from a four-stroke of comparable net output. You might get white smoke galore... something I used to see all the time on old PC FL9s trying to accelerate out of Harmon with harrumphing and sighing as the engineers pumped them up to where they'd hold power... but as Randy points out, even if there were to be a short burst of flame in the rich exhaust, it would go out as soon as there was excess air in the exhaust. I leave it up to the Alco boys to tell whether the black smoke from 244s (et al.) via turbo lag could be ignited long enough to cause big problems -- my guess would be that any flaming exhaust would go out once the turbo came up to speed and provided adequate combustion-air mass flow for the commanded fuel setting. Randy (et al.) -- tell us more, more, more... Reply mudchicken Member sinceDecember 2001 From: Denver / La Junta 10,820 posts Posted by mudchicken on Wednesday, March 30, 2005 8:13 AM One of those four cycles isn't......Also, the GE Cooper Bessemer design has gone about as far as it can go. The newer engines out of Erie have their Alco-like teething problems. (the more things change, the more they stay the same) Mudchicken Nothing is worth taking the risk of losing a life over. Come home tonight in the same condition that you left home this morning in. Safety begins with ME.... cinscocom-west Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Wednesday, March 30, 2005 4:41 AM QUOTE: In 20 years of working on locomotives I've never seen a stack fire as a result of turbo seal failures. I have covered parking lots full of vehicles in lube oil, had to repaint some trackside houses, but never had a fire because of lube oil out the stack. Bottom line is the lube oil coming out the stack isn't any where near it's flashpoint. There is no design problem with the GE turbo seal. Randy Randy, I think you are right on this, and I was wrong. Having driven a diesel truck during a turbo seal failure, I do remember the oil coverage on the following trailer that I was pulling. But then again I seem to remember witnessing a real turbo fire. Flashpoint is really the wrong term to apply when talking about this subject, the right term is autoignition, from what I've read after your posting. As I now understand it, flashpoint has to to with transportation standards and autoignition has to do with engine fuel combustion. From time to time I pick-up at Globe Turbo, I think I'll ask one of the engineers at that place this question. Globe Turbo is the OEM source for turbos for Alco locomotives. This is very much subjective, but I've never seen photos of a turbo'd EMD stack fires, but lately there are many photos of GE turbo'd stack fires being posted on the web. What's going on here? Can you explain? Jim Reply Edit Randy Stahl Member sinceJune 2004 From: roundhouse 2,747 posts Posted by Randy Stahl on Thursday, March 24, 2005 9:06 AM QUOTE: Originally posted by SP9033 QUOTE: Originally posted by SILVERCHAMPION [8D]Why do I see fire coming out of diesels locos As mentioned before, stack fires from turbo engine'd diesel locomotives, is most generally a result of the failure of the turbo bearing's oil seal. Mostly, nothing else will cause this condition. Apparently, GE locomotives suffer this condition more often than EMDs, which would indicate a design problem with GE's prime mover's turbo oil seal. A stack fire is not to be confused with fire out of the stack of a naturally aspirated diesel engine'd locomotive. Two entirely different happenings. Jim - Lawton, NV MP 236 In 20 years of working on locomotives I've never seen a stack fire as a result of turbo seal failures. I have covered parking lots full of vehicles in lube oil, had to repaint some trackside houses, but never had a fire because of lube oil out the stack. Bottom line is the lube oil coming out the stack isn't any where near it's flashpoint. There is no design problem with the GE turbo seal. Randy Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, March 24, 2005 5:20 AM QUOTE: Originally posted by SILVERCHAMPION [8D]Why do I see fire coming out of diesels locos As mentioned before, stack fires from turbo engine'd diesel locomotives, is most generally a result of the failure of the turbo bearing's oil seal. Mostly, nothing else will cause this condition. Apparently, GE locomotives suffer this condition more often than EMDs, which would indicate a design problem with GE's prime mover's turbo oil seal. A stack fire is not to be confused with fire out of the stack of a naturally aspirated diesel engine'd locomotive. Two entirely different happenings. Jim - Lawton, NV MP 236 Reply Edit Overmod Member sinceSeptember 2003 21,669 posts Posted by Overmod on Thursday, March 24, 2005 4:36 AM jextra, he's talking about the air horns. Shop staff took the chime horn off an E7 scheduled to be scrapped. My data indicate that 9042 made it to Conrail, but was traded to EMD; be interesting to know what happened to her. Reply jextra Member sinceDecember 2004 8 posts Posted by jextra on Wednesday, March 23, 2005 9:54 PM What are the Nathan Air Chimes that Captain Jack mentioned in the stack fires thread? Reply CSXrules4eva Member sinceAugust 2004 From: Louisville, KY 1,345 posts Posted by CSXrules4eva on Saturday, March 19, 2005 9:15 PM QUOTE: Originally posted by adrianspeeder Tell ya what, "dieselenginegirl" aka Sarah, knows her stuff... One other reason you get smoke, is people like me that "turn up the fuel" to get that little bit more horsepower to the wheels... Adrianspeeder PS: "Real engines don't have sparkplugs!" Yes your right about that one!! Real engines don't use spark plugs!!!! And they don't sound like rice burners either!! Thanks for the compliment :) I've lived around people that eat sleep and breath diesel, thats how the knowledge rubbed off on me. I also work at a diesel shop so thats also another source of information for me. LORD HELP US ALL TO BE ORIGINAL AND NOT CRISPY!!! please? Sarah J.M. Warner conductor CSX Reply GMS-AU Member sinceMay 2004 From: Australia 56 posts Posted by GMS-AU on Saturday, March 19, 2005 1:29 AM Howdy All One other point that might be relevant here is the relatively short length of exhaust pipe for the engine size. After exiting the cylinder then through the turbo its only a short distance to the outlet in the hood. Cars exhaust travels at least two metres or 6' before it opens and trucks, especially conventional/bonneted trucks, the exhaust is also quite long. Therefor if there is the same occurrence in a car or truck it will be consumed by other gases and go through a muffler and or a catalytic converter in the case of a car before it reaches the atmosphere. You may notice drag cars ( or trucks ) doing the flame thing but the manifold pretty well comes straight out of the engine and the engines are highly tuned and running rich. Mack truck engines were or are good smokers for similar reasons and that is why the Mack V8 truck engines has been dropped from production as it had light years to go before it had a hope of meeting emission standards. As in Adrians case you can turn up the pump and diesels will smoke but all that smoke is unburnt fuel and you are paying for it to be pumped into the atmosphere. A good running diesel will not smoke even under load and a good driver will also be able to lessen the amount of smoke produced by a diesel. This will be harder in a diesel loco as the engine is run to suit the needs of the alternator and trains are often underpowered so every bit of power is needed to keep the train going. G M Simpson There is no replacement for displacement! Reply 12 Join our Community! Our community is FREE to join. To participate you must either login or register for an account. Login » Register » Search the Community Newsletter Sign-Up By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy More great sites from Kalmbach Media Terms Of Use | Privacy Policy | Copyright Policy
QUOTE: In 20 years of working on locomotives I've never seen a stack fire as a result of turbo seal failures. I have covered parking lots full of vehicles in lube oil, had to repaint some trackside houses, but never had a fire because of lube oil out the stack. Bottom line is the lube oil coming out the stack isn't any where near it's flashpoint. There is no design problem with the GE turbo seal. Randy
QUOTE: Originally posted by SP9033 QUOTE: Originally posted by SILVERCHAMPION [8D]Why do I see fire coming out of diesels locos As mentioned before, stack fires from turbo engine'd diesel locomotives, is most generally a result of the failure of the turbo bearing's oil seal. Mostly, nothing else will cause this condition. Apparently, GE locomotives suffer this condition more often than EMDs, which would indicate a design problem with GE's prime mover's turbo oil seal. A stack fire is not to be confused with fire out of the stack of a naturally aspirated diesel engine'd locomotive. Two entirely different happenings. Jim - Lawton, NV MP 236
QUOTE: Originally posted by SILVERCHAMPION [8D]Why do I see fire coming out of diesels locos
QUOTE: Originally posted by adrianspeeder Tell ya what, "dieselenginegirl" aka Sarah, knows her stuff... One other reason you get smoke, is people like me that "turn up the fuel" to get that little bit more horsepower to the wheels... Adrianspeeder PS: "Real engines don't have sparkplugs!"
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