How reliable are the diesel engines in comparison to an automobile (for us novice), lets say, or the electric trains?
Railroad Forums
Moderator: Liquidcamphor
I assume you are talking about the prime mover of a locomotive. EMD (Electro Motive Division of GM) 710 series diesel engines are a refinement of a design that dates back to 1938. These engines maintained in a proper fasion are engineered to go one million miles between overhauls. If you are talking about a locomotive as the sum of all parts, then that can vary from locomotive model to locomotive model. The 3000 hp 645 series engine in a GP or SD series locomotive is especialy reliable. That same engine, uprated to 3700 horsepower in the 50 series locomotive became un-reliable. The 710 series engine in the 16 cylinder configuration (4000hp) is the best engine EMD has made yet. The 710 12 cylinder engine (3000hp) in my book is too stressed to be what I would consider a longevity engine.
Paul
"We are all here because we are not all there."
"We are all here because we are not all there."
How is the V12-710G any less reliable than the V16-710G?
Both have the same architecture and a rated output of 250hp/cylinder.
Both have the same architecture and a rated output of 250hp/cylinder.
Thanks Paul,
I was thinking along the lines if you were going to go out and by one for the family, something that gets 200,000, last for 12 years (not Japanese).
I was thinking along the lines if you were going to go out and by one for the family, something that gets 200,000, last for 12 years (not Japanese).
Believe it or not but average locomotive on LIRR or MNCR does about 100 000 miles a year, in a lifetime the engine block rarely gets changed, in about 8 years usualy the power Assemblies get changed out but thats about it.
so yes an engine will usualy last about 15 to 20 years.
reliable I say so even your car has a few hickups every year. on lovcomotives the hickup's are mostly in llink between seat and throttle.
yes the human interface screwing up
so yes an engine will usualy last about 15 to 20 years.
reliable I say so even your car has a few hickups every year. on lovcomotives the hickup's are mostly in llink between seat and throttle.
yes the human interface screwing up
If Conductors are in charge, why are they promoted to be Engineer???
Retired Triebfahrzeugführer. I am not a moderator.
Retired Triebfahrzeugführer. I am not a moderator.
How is the V12-710G any less reliable than the V16-710G?
Both have the same architecture and a rated output of 250hp/cylinder.
Easy answer: Internal harmonics that cause crankshaft breakage.
The 710- 16 cylinder engine fires every 22.5 degrees of crank shaft rotation @ TDC, 360º / 16 = 22.5º. If we follow that theory then the 12-710 should fire every 30º of crankshaft rotation, BUT- the firing order @TDC is
1 - 12 - 7 - 4 - 3- 10 - 9 - 5 - 2 - 11 - 8 - 6
0º 19º 45º 94º 120º 139º 165º 214º 240º 259º 285º 334º.
Notice the differances in the amount of crankshaft rotation in degrees between cylinders, and also notice that the 7th cylinder to fire (#9) fires at 165º, not at 180º. Normally, the halfway cylinder always fires at 180º of the #1 cylinder. This firing order was changed in later 12-710 engines that are now designated 12N-710G3B-EC and are computer controlled. This was done to place the 7th cylinder to fire at 180º of the first cylinder to fire, but there is still an oddball amount of degrees between cylinder firing. Along with the new firing order, also came a differant harmonic ballancer used ONLY on the 12N-710. This is of a pendulum design and it absorbs the peculular harmonics of the 12 cylinder engine. I do not know if the later 16-710s have this design or if it is still 12 cylinder only.
I must now go rest my brain.
Both have the same architecture and a rated output of 250hp/cylinder.
Easy answer: Internal harmonics that cause crankshaft breakage.
The 710- 16 cylinder engine fires every 22.5 degrees of crank shaft rotation @ TDC, 360º / 16 = 22.5º. If we follow that theory then the 12-710 should fire every 30º of crankshaft rotation, BUT- the firing order @TDC is
1 - 12 - 7 - 4 - 3- 10 - 9 - 5 - 2 - 11 - 8 - 6
0º 19º 45º 94º 120º 139º 165º 214º 240º 259º 285º 334º.
Notice the differances in the amount of crankshaft rotation in degrees between cylinders, and also notice that the 7th cylinder to fire (#9) fires at 165º, not at 180º. Normally, the halfway cylinder always fires at 180º of the #1 cylinder. This firing order was changed in later 12-710 engines that are now designated 12N-710G3B-EC and are computer controlled. This was done to place the 7th cylinder to fire at 180º of the first cylinder to fire, but there is still an oddball amount of degrees between cylinder firing. Along with the new firing order, also came a differant harmonic ballancer used ONLY on the 12N-710. This is of a pendulum design and it absorbs the peculular harmonics of the 12 cylinder engine. I do not know if the later 16-710s have this design or if it is still 12 cylinder only.
I must now go rest my brain.
Paul
"We are all here because we are not all there."
"We are all here because we are not all there."
Paul --
Fascinating.... So does the same go for any V12? Or is this just a quirk of the V12-710G?
Fascinating.... So does the same go for any V12? Or is this just a quirk of the V12-710G?
Alco engines are a horse of a different color. They are four stroke cycle engine, as compared to EMD's two cycle. Only half of the given amount of cylinders fire on one rotation of the crankshaft on a four stroke as opposed to all cyilnders firing on one rotation of the crank shaft of a two cycle engine.
It has been many years since I have worked on either a 244 or 251, but if I remember correctly, the engine fired as if it was a big in-line six.
Unlike EMD, Alco (and GE as well) number the cylinders by bank side and number... in other words, #1L,-1R,-2L,-2R,-3L,-3R etc. L meaning Left bank, R being Right bank. The way I remember is that they fired the Left and Right banks only a few crankshaft degrees apart, like I said a big six cylinder engine. So, it would be something like, but maybe not exactly... fires #1 Right, crank rotates a few degrees then fires #1 Left, rotates, fires #6R,6L,- 5R-5L 4R-4L-3R-3L 2R-2L. or close to that. That's what gave the Alco engine it's unique sound. If I am wrong, I am sure I will be corrected but remember it's been over fifteen years since i have been around these thing on a daily basis. One interesting thing is that the firing order on the new 6,000 hp EMD 265H four cycle engine is the same as the 16-710.
It has been many years since I have worked on either a 244 or 251, but if I remember correctly, the engine fired as if it was a big in-line six.
Unlike EMD, Alco (and GE as well) number the cylinders by bank side and number... in other words, #1L,-1R,-2L,-2R,-3L,-3R etc. L meaning Left bank, R being Right bank. The way I remember is that they fired the Left and Right banks only a few crankshaft degrees apart, like I said a big six cylinder engine. So, it would be something like, but maybe not exactly... fires #1 Right, crank rotates a few degrees then fires #1 Left, rotates, fires #6R,6L,- 5R-5L 4R-4L-3R-3L 2R-2L. or close to that. That's what gave the Alco engine it's unique sound. If I am wrong, I am sure I will be corrected but remember it's been over fifteen years since i have been around these thing on a daily basis. One interesting thing is that the firing order on the new 6,000 hp EMD 265H four cycle engine is the same as the 16-710.
Paul
"We are all here because we are not all there."
"We are all here because we are not all there."