Peter and Broncoman — aren’t the V angles for EMD’s closer to 45 deg than 90 deg? Eyeball from the catwalk would suggest that.
Dave, Eric,
Yes, the EMD vee engines have a 45 degree vee angle, in the 567, 645 and 710 series engines. The older 201A engines however, at least the V12 and V16 engines had a 60 degree vee angle (the 6 and 8 cylinder 201 and 201A engines were in line engines).
The Alco 251 vee engines and the GE FDL and HDL engines are also 45 degree vee engines, and it appears from available details that the GEVO is also a 45 degree vee engine.
There are 90 degree engines used in locomotives, but generally smaller than the EMD and GE engines. An example is the MAN B&W (Paxman) VP185, used in some British class 43 High Speed Train power cars (and all of the similar Australian XPT power cars).
I thought I should check my facts before posting this!
Peter
EMD 710 and GE FDL are both 45 deg V angle, which makes for even firing…well, except the GE engine has a main/articulating rod arrangement instead of having both conn rods down on the crank, which “un-evens” things a bit.
Don,
The rod arrangement you spoke of is unfamiliar to me. Could you elaborate. The max size of stuff I work on is in the 10-12 liter range.
Thanks
Dave
Dave,
The GE FDL engines, and the Cooper-Bessemers that preceded them, had articulated rods. The best way to check this out is to follow the GE Transportation link in Ulrich’s earlier posting, through technology to the cutaway drawing of the FDL engine. As viewed, the left hand rod is normal design with a little end at the top and a big end with a crankshaft bearing at the bottom. On the right side, the rod is almost symmetrical, connecting to the gudgeon pin at the top and a similar pin at the bottom, attached to the big end of the left hand rod. (Trust me, the drawing makes it quite clear). There may be photos of the rods elsewhere on the GE web site.
The alternative, used in the Alco and GE HDL engines, is to have the two rods side by side on the crank. The advantage of the articulated rod is that you have a big single bearing on the crank which allows higher bearing pressures without risk of damage to the crank or bearing. The disadvantage is that the stroke of the piston on the articulated rod is slightly different, since the path the bottom end follows is not exactly the same as the crank because of the offset of the bottom end pivot point from the centre of the crank bearing. This difference in stroke isn’t very big, a small fracrion of an inch (GE don’t quote this in any data I’ve seen, but the Chinese 12-240ZA built in the Beijing factory quoted about one sixteenth of an inch).
This difference in stroke will affect the balance and the power very slightly. but is presumably taken into account in the balancing process. I assume the length of the articulated rod is such that the difference in stroke occurs at the bottom, allowing the same power assembly (at least cylinder, head and liner) to be used on each side of the engine.
This might be one of the causes of the “Chugging” noise made by GE engines under load, but sixteen cylinder Alcos with single pipe exhaust manifolds sound very similar (but not identical). Has anyone compared GE FDL and HDL sounds,
Guys,
A couple of corrections to my last posting. The Beijing engine is a 12-240Z (not ZA). But more importantly, my recollection of the stroke difference between the main and articulated side was wrong. The figures for the Chinese engine are; main 260 mm, articulated 273.51 mm. The quoted FDL stroke is 266.7 mm for the main rod (I assume), and even if GE managed to get the offset less than in the Chinese engine, the stroke difference must be about 12.5 mm (or about half an inch). As Don said, this must affect the balance of the engine and the smoothness of power delivery (and may contribute to the “chugging” sound).
Peter
Hi Peter,
I´m trying to be back - But the WLAN works not well at the moment!
Sometimes it works sometimes not!
BTW: I don´t know the article about the SD70ACe !!!
My February issue of trains was lost in the German Post! Will become a new in the next days!
Ulrich,
I only got my February Trains magazine two days ago. There wasn’t much new in the text except there was a section covering the new GE locomotives that are the subject of this thread, giving a GE code of ES44AC (and ES44DC for the other version), where ES stands for Evolution Series.
The photos of the SD70ACe were very interesting. There was a much greater similarity of appearance with the GE Dash 9 and AC series locomotives than I expected, pparticularly on the left side behind the cab, where it appears that the forward inverters have been placed in the same position as in the GE locomotives,. Air intakes look a lot like the GE as well, but the radiators and dynamic brakes are still arranged like the SD90.
The SD70ACe is not really an SD70 at all, and I don’t know why EMD use this description, except that the SD70M is selling well right now. This is more like a rearranged 710 engined SD90MAC, sometimes called an SD9043MAC. The arrangement of equipment on the left side behind the cab on these (SD90MAC) units is really messy, at least in appearance! No other SD70 has had a 4300HP engine, that’s what an SD75 had! If they have managed to save nearly six feet of frame length (compared to an SD90MAC) by rearranging equipment, that’s pretty good!
Anyway, I look forward to your ideas on the similarity between the new EMD and GE units.
One thing I didn’t quite pick up on with the ES44AC (look, I’m back on the thread subject again) was the use of air to air intercooling on the GEVO engine. This takes up more room than using water through intercoolers, which is usual, but is more efficient. It probably uses up the space made available by using a 12 cylinder rather than a 16, and is located just in front of the radiator. This is on the GE website, I just didn’t read it properly the first time.
Peter
Was a Cooper-Bessemer based engine the basis for the G.E. designed engines?
I agree Peter, I think that the SD70ACe looks more like a SD90 or alot like a SD89. I think it should have been a SD85, but I am not a marketing expert. I haven’t seen a AC45 in life but the radiator assemblege looks more like a AC6000/6044.
Dave,
The GE FDL engine was based on the Cooper Bessemer FVL, and later FVBL engines, which were basically the same as the early GE FDL engines. I think the early export U series used engines still called Cooper Bessemer FVBL. The GE 70 ton locomotives used a six cylinder inline version called an FWL-6T.
I think the air to air intercooler, located in front of the radiator, makes the ES44 look more like the AC 6000. Those are really big units - they make a Dash 8 look like a model to a smaller scale, and the radiator is the biggest part.
Peter
I love ES44’s. Unfortunately bnsfengineer doesnt with his freq experience. He doesnt realize (with AC units, that going N8 with the throttle with heavy loads WILL cause wheelslip. All you have to do is simply start slow. Sander on mabey[soapbox]
I find it quite amusing, Mr. Creator, that you state in another thread that you are not a railroader, that your only experience is with Trainsim, and yet you feel qualified to critique those who actually are railroaders.