• C39-8's

  • Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.
Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.

Moderators: AMTK84, MEC407

  by MR77100
 
Let's continue our discussion of the C39-8's here.
  by shortlinerailroader
 
Elsewhere in this forum (favorite GE engine) I mentioned a couple of instances where I have seen Norfolk Southern C39-8s emit fire from the exhaust stack. It was quite a sight, and someone on this forum has an image of this as his icon. Is there simply too much fuel vs. air going to the cylinder(s), or is it more complicated than that?

  by MR77100
 
I think is has more to due with a blown turbocharger. I remember seeing a Conrail B40-8 in a video with a blown turbocharger, and the pyrotectnic display was incredible. GE are notorious for doing this.

  by trainiac
 
I think it's due to a broken or damaged fuel injector that ends up dumping substantial quantities of fuel into one of the cylinders. From what I've seen, failed turbochargers don't cause flames...Just a whole bunch of black smoke.

  by Umblehoon
 
Anyone have any pictures of this? I'd really like to see something like this happening!
  by Allen Hazen
 
Re: "GE are notorious for doing this." Alcos could have the same problem. The only time I remember seeing a Penn Central C-636 (probably in the Spring of 1976, so it would technically have been a Conrail unit by then) it had a "torch" from its stack. (It was the second -- or later -- unit on an Eastbound passing East Liberty (Pittsburgh neighborhood) on the ex-PRR main-- whether or not the crew were aware that one of their locomotives was hurting, the train kept going. I suspect stopping there, on a hill on a busy main line in the middle of a city, was not considered a good idea.)

  by nolifeCRchaser
 
The flames shooting out of the stack are mainly due to excess fuel and oil getting into the exhaust. It is mainly due to lack of maintenance and improper train handling. About a month or two ago we had a GP-40-2 that they wanted to use on the circus train, which had a flame-throwing problem, so the flames are not just a GE thing. The GP-40-2 had mechanical problems which caused the flames as they started from the moment the engine was started to when we shut it down about 45 minutes later. You can make just about any diesel engine shoot fire. Dash 7's were notorious for flamethrowing as well. Lately, we have been throwing flames with the trash9's just for chuckles, because they are junk. Not good for the engine, but very cool to see at night. An even better sight is when the compressors on the trash 9's blowup. I have seen a lot of the trash 9's with the burn marks around the center of the engine, but I have not seen many C39-8's or 40-8's with any fire damage. Every so often a -8 will venture into the yard with burn marks, but not as bad as the ones I have seen on the trash 9's. As mentioned in an earlier post, a blown turbocharger causes a lot of black smoke and oil, but no fire.
  by shortlinerailroader
 
Umblehoon wants to know where there are pics of this. The only online photo of this happening is in Metalcowboy's icon on this forum. Also, Highball Productions has a video--KCS and Kudzu--that has a C39-8 shooting flames. Oh yes, the time I saw this happening it was indeed at night.

  by DutchRailnut
 
any four stroke engine will flame if you load it to fast. its just that engine is reving up without the Turbo being up to speed to provide combustion air.
http://www.railpictures.net/viewphoto.php?id=49426
  by rocketman
 
Gp40-2's with F-O-S have no comparison with GE's and the same problem. EMD's use a unitized injector where pressurization, metering, and injection are all performed within the same housing. GE's use a two piece per cylinder method. Fuel is pumped around 70 psi through headers that run along each bank of the engine. The headers bolt to a "pump" on each cylinder. The pump is actuated by a push rod off of each cylinder. From the top of the pump is a high pressure fuel line that carries I would like to say around 10,000 psi (depends on the locomotive and whether or not it has EFI). The high pressure fuel line is connected to a "nozzle" atop each cylinder. The nozzle converts the pressure and velocity of the fuel and atomizes it through atip with multiple fine holes drilled on the bottom of it. I know GE messed around with increasing the high pressure on the output of the pump with some of the Dash 8's, especially the early EFI models, and experienced a problem with the tips of the nozzles breaking off - which ultimately lead to a fire out the stack situation. Thus would result in loading up the exhaust and enventually coming out as a fire ball. Generally speaking from my experience with them, fire out the stack on a GE could be caused by an array of issues. Most notable is if there's a problem with a fuel pump. They can wear out. Sometimes it could be a camshaft or camroller problem, I have seen them jammed up before. Sometimes it's the turbo. If the turbo has problems spinning, especially on a GE, an imbalance between air sucked in, air forced in and an excessive back pressure on the exhaust trying to spin it can often result in FOS. Plugged air filters on rare occasion can also be tied in with the same problem. Mostly FOS becomes evident particularly when the throttle is advanced quickly and heavily. As noted above any added resistance forces the engine to suck harder and compensates with fuel. GE turbos get very hot sometimes and creates the perfect environment for FOS. EMD's on the other hand rarely experience fire out the stack. The few cases I have dealt with usually relate to a bad turbo or a severe problem with fuel. I have witnessed some EMD's with FOS, but again the turbo or a really bad injector was the culprit. EMD turbos can and will get plugged with carbon, and the imbalance can cause a phen. known as woofing but rarely have I ever seen it lead to any flames, just alot of smoke and really unusual noise.

  by FDL4ever
 
"GE turbos get very hot sometimes and creates the perfect environment for FOS. EMD's on the other hand rarely experience fire out the stack. The few cases I have dealt with usually relate to a bad turbo or a severe problem with fuel."

I think a lot of it has to do with the conditons in the exhaust flow of a 2-stroke versus a 4-stroke engine, too. EMD 2-strokes have a lot of excess air in the exhaust which is blown through the cylinders by the super/turbochargers during the interval where the inlet ports are uncovered and the exhaust valves are open (scavenging). That tends to dilute any excess fuel from a bad injector so that any fire it might create is either very brief and contained inside the exhaust trunking or is much less orange in color and harder to see if it extends out the stack. When a GE or Alco 4-strokes (and just you wait- the H-engines will do it too when they get old!) has a bad injector or pump that is dumping a lot of raw fuel through the system, it can't really burn in the exhaust plumbing because there's very little surplus oxygen in the exhaust of a 4-stroke diesel. When the heated-up unburned fuel gets out the stack and meets up with some oxygen, and then it burns in an orange plume.

  by MEC407
 
As you can see from the icon next to my name, not just C39-8s throw flames from the stack. Old U-Series locos did it quite frequently too. Even when they were in good working order.

  by nolifeCRchaser
 
Does anyone know what railroads other than Norfolk Southern, Conrail, and CSX purchased C39-8's, if any? I know that NS had/has the bulk of the C39 fleet, Conrail had a handful, and CSX had 2 or 3 that I know of prior to split date.

  by TerryC
 
CSXT got 9 C39-8's from the infamous Conrail merger. I do not know why only Norfolk Southern and Conrail bought them.

http://trainiaxindex.cjb.net/

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