Reading an article on early diesel locomotives, I came across the term "true diesel."
As opposed to what?
Still in training.
Lithonia Operator Reading an article on early diesel locomotives, I came across the term "true diesel." As opposed to what?
Back in the day there were semi-diesels as opposed to true diesels.
"The semi-diesel or hot-head engine is not a true diesel, but retains the operating functions of the diesel with the exception of high compression. On these engines, the head or a bulb in the combustion chamber is heated to near red heat, usually with a kerosene torch. The engine usually has a manual pump that will force an amount of fuel that will be sprayed through a nozzle in the combustion chamber against the heated area. As the engine is rolled against compression, the manual pump is activated and the sprayed fuel ignites. This in turn creates pressure in the combustion chamber against the piston, thus starting the engine."
Remember the model airplane you flew as a kid? The one where you attached leads from a battery to heat the cylinder before you released the spring loaded prop? That's what's known as a glow plug engine, the semi-diesel is a giant version of that. Notice how the heating leads are removed at the beginning of this video
1962 Herkimer OK Cub .024 c.i. model glow plug engine - Bing video
What makes it a "semi-diesel" is that there is no sparkplug, like an Otto type engine, but engine compression is not high enough to heat the air in the cylinder to a temperature where the fuel ignites when injected, like a Diesel.
Here is a video of a semi-diesel in operation - note the use of the torches to heat the cylinders before it is cranked up
Gardner 4T5 Semi Diesel - Anson Engine Museum - - Bing video
Thanks, Beau. Got it.
50+ years ago, I was told that locomotive and truck diesels aren't true diesels -- it's ships that have true diesels. Don't recall the difference -- maybe the huge slow-turning diesels come closer to maintaining constant pressure during the piston stroke, and that's the criterion?
My sailboat's diesel engine has glowplugs to use on cold days. On warm days it will start without use of the glowplugs.
Is it a true diesel?
Lithonia OperatorIs it a true diesel?
Or a true sailboat?
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
If your air intake faces into the wind, does that count as supercharging?
Diesel engines engines ignite from the heat of compression once started, the glow plugs are no longer needed once the engine fires.
Hot bulb engines have a much lower compression ratio and do not ignite from compression alone. This is a double edged sword, they can run on a variety of liquid fuels but if run at very low load the engine won't generate enough heat to keep the bulb hot and it will die (this is also possible on diesels, but it is rare and I've only heard of it happening at idle in very cold weather).
Greetings from Alberta
-an Articulate Malcontent
zugmann Lithonia Operator Is it a true diesel? Or a true sailboat?
Lithonia Operator Is it a true diesel?
Do the Diesel engines in locomotives have glow plugs?
I don't think so.
Besides, at temperatures where they are needed you would also run into bigger problems with cooling water freezing and poor lubrication from cold oil upon starting. And more cranking power being needed due to cold oil.
I've seen old EMDs cold started at about 5 degrees above freezing a few times. They go but they aren't happy.
I recall reading a story on another forum about a shortline operator who had antifreeze in their EMDs and sometimes had to start them outside during winter. In addition to having block heaters they would put a couple stock tank heaters in the crankcase to warm up the oil and thin it a bit.
SD70DudeI don't think so. Besides, at temperatures where they are needed you would also run into bigger problems with cooling water freezing and poor lubrication from cold oil upon starting. And more cranking power being needed due to cold oil. I've seen old EMDs cold started at about 5 degrees above freezing a few times. They go but they aren't happy. I recall reading a story on another forum about a shortline operator who had antifreeze in their EMDs and sometimes had to start them outside during winter. In addition to having block heaters they would put a couple stock tank heaters in the crankcase to warm up the oil and thin it a bit.
Remember - Gen 1 diesels were left to run 24/7 back in the day. They only had plain water as their cooling fluid and their normal lubricating oil was in the 80-90 range and at normal room temperatures was more akin to grease that it was to oil.
Even today engines without AESS (Automatic Engine Start Stop) when they are shut down and the expected ambient temperature will be 40 degrees F or less, the rules (at least on CSX) were for the cooling system to be drained to prevent damage from freezing as the cooling system is still plain water - not antifreeze.
Never too old to have a happy childhood!
Locomotive cooling water has used an anti corrosion treatment for decades. It gives the water a green color that looks like anti freeze but is supposed to be non toxic. It still makes a nasty looking puddle when it drains onto the ground.
I've seen green, pink and purple in water sight glasses over the years. Not to mention plain old clear water after we refilled one that ran out.
I suspect and hope that the railroads now use the borate/nitrite treatments, as opposed to the chromium compounds that became infamous after the Hinckley, CA groundwater contamination case (Erin Brockovich).
https://heritagerailalliance.wildapricot.org/resources/Documents/Maintenance%20Instruction%20Book%201748E-LOCO-ENGINE-COOLANT-1991-MAY.PDF
The 'non-true-diesels' in this context will almost certainly be "distillate engines", like the original powerplant in the Union Pacific M-10000. These are fascinating in their construction and operation.
There is some material on the Web from a group that actually restored one of these engines, in a railcar, to operation. The engine has comparatively large bore, and runs with high compression, but uses spark ignition for timing -- the engine in question having 4 plugs per cylinder!
Naturally as soon as proper solid injection, either with injection pumps improved a la Cummins or with 'jerk' pumps, was worked out, the compression-ignition Diesel cycle offered better economy with fewer compromises -- the GM 2-stroke directed research that culminated in the 201A and then 567 being a compelling example.
For fun, look up Fritz Huber's engine for the Lanz Bulldog, an engine that can idle at zero net rpm. There are a number of videos that show the starting ritual, often involving a somewhat lavish amount of flame, and others that show the 'dance' when the engine is run very lean. These always make me think of the original Thernolokomotive fiasco, although of course very different principles were involved in detail design...
OvermodFor fun, look up Fritz Huber's engine for the Lanz Bulldog, an engine that can idle at zero net rpm. There are a number of videos that show the starting ritual, often involving a somewhat lavish amount of flame, and others that show the 'dance' when the engine is run very lean. These always make me think of the original Thernolokomotive fiasco, although of course very different principles were involved in detail design...
https://www.youtube.com/watch?v=tr_b6mTnHEo
timz 50+ years ago, I was told that locomotive and truck diesels aren't true diesels -- it's ships that have true diesels. Don't recall the difference -- maybe the huge slow-turning diesels come closer to maintaining constant pressure during the piston stroke, and that's the criterion?
A "true" Diesel is an engine that uses a true Diesel cycle, where fuel is injected slowly to maintain constant pressure in the power stroke. Most diesel engines are effectively using the Otto cycle (combustion takes place almost entirely at the beginning of the power stroke) substituting compression ignition for spark ignition.
One of the great innovations that true electronic fuel injection brought to compression-ignition direct-injection engines is the ability to perform both pilot injection and modulated main-charge injection, to give the best 'compromise' among constant-pressure rise, pressure rise relative to crank angle, and high-speed capability.
Ford apparently got into a little trouble when it converted the VT365 schoolbus engine for higher performance. Apparently the original program for pilot injection did not recognize that the flow from the nozzles in this application was supersonic, and the resulting shockwaves caused 'trouble' with the subsequent lightoff of the main injected charge. Quickly and quietly pilot injection disappeared from the engine program...
Overmod Ford apparently got into a little trouble when it converted the VT365 schoolbus engine for higher performance. Apparently the original program for pilot injection did not recognize that the flow from the nozzles in this application was supersonic, and the resulting shockwaves caused 'trouble' with the subsequent lightoff of the main injected charge. Quickly and quietly pilot injection disappeared from the engine program...
That was probably the least of the many, many problems with those engines, and perhaps the only one that Ford fixed on their own.
If VT365 sounds foreign, Ford branded them as the 6.0 and 6.4 Power Stroke engines.....
TRUST ME when I say I know the problems with the 6.0L PowerCerebrovascularAccident.
Ford replaced so many that they devised a way to pull the engine without the previously-required full body lift. One step of the factory procedure involved 17 wobble extensions in series.
It turned out you could build a reasonably stable 6.0 if you did the right things with the right parts... ARP head studs tensioned to something like 425ft/lb, full EGR delete complete with machined plug, carefully rebuilt injectors with laser-profiled nozzles... etc. I had no real complaint with a 28mpg Excursion (no Gear Vendors, either) when all was said and done, but the list of design boners that should never have been committed was astoundingly large.
I will admit I was puerile the second time I was told the shop could find nothing wrong with my injectors -- I pulled around, went back in, and in front of the service writer's desk dropped it in neutral and ran the engine up to about 4000rpm. Filled all the bays with smoke in about 20 seconds. That did not help them find the problems although it certainly motivated them to do so.
I have doubts.
How much documentation would you need?
(I confess I only know up to about 2012 in detail, and only the 6.0L, not the revised piezoelectric-injector 6.4)
OvermodTRUST ME when I say I know the problems with the 6.0L PowerCerebrovascularAccident. Ford replaced so many that they devised a way to pull the engine without the previously-required full body lift. One step of the factory procedure involved 17 wobble extensions in series. It turned out you could build a reasonably stable 6.0 if you did the right things with the right parts... ARP head studs tensioned to something like 425ft/lb, full EGR delete complete with machined plug, carefully rebuilt injectors with laser-profiled nozzles... etc. I had no real complaint with a 28mpg Excursion (no Gear Vendors, either) when all was said and done, but the list of design boners that should never have been committed was astoundingly large. I will admit I was puerile the second time I was told the shop could find nothing wrong with my injectors -- I pulled around, went back in, and in front of the service writer's desk dropped it in neutral and ran the engine up to about 4000rpm. Filled all the bays with smoke in about 20 seconds. That did not help them find the problems although it certainly motivated them to do so.
Making it clear, to me, why so few 'automobile' manufacturers are building the diesels that they are putting in their products - leaving the engine production to the experienced diesel enging builders - Cummins, Detroit Diesel etc.
Just having experience in manufacturing gasoline internal combustion engines doesn't give one all the tricks of the trade required to build long lasting properly operating diesels.
"Not a true diesel" could refer to the early "oil-electric" (occasionally "gas-electric") locomotives.
I believe the first was built for the Minneapolis St.Paul Rochester & Dubuque Electric Traction Co., better known as the "Dan Patch Electric Line", in 1913. They wanted to build a railroad with overhead wire electricity, but were concerned about the expense of putting up the wire. GE offered to put an oil-burning electric generator into an otherwise standard GE boxcab electric engine. That allowed the engine to run independently right away, but it could be later converted to straight electric.
After the railroad's founder, Col. Marion Savage, died in 1918, the railroad was reorganized as the Minneapolis Northfield and Southern Ry. It sold off it's internal-combustion engines and began using steam, although they began buying diesel locomotives shortly before WW2. #100 was eventually converted to straight electric by a subsidiary of GN IIRC. It is now on display at the MN Transportation Museum's Jackson St. Roundhouse just north of downtown St.Paul.
No, it does not - look up 'Semi-Diesel"
"Oil-Electric" was a euphemism, like Liberty Cabbage or Liberty Hound, to avoid the G-word context after the Great War. It avoided having to mention the hatable Hun name of the inventor of pure compression ignition.
The motors in the Canadian road locomotive were Beardmores, designed for airship use and hence light enough for rail express use. To my knowledge the Ingersoll-Rand switchers used compression ignition, although I don't remember offhand if direct or indirect injection. That was long before Ricardo invented the swirl chamber that made high-compression-ratio IDI engines so good.
The 567 and its successors are all, of course, direct injection engines, and prior to EFI were completely mechanical... a jerk-pump design akin to the 8.2L Detroit (an engine highly dependent on precise volumetric equality of all 8 cylinders, which was accomplished with calibrated washers chosen at the factory)
I can't remember a locomotive engine with glow plugs in the head or intake.
A key difference with the 'semi-diesel' is that it still relies on heat to volatilize the fuel in the intake charge, then uses high compression to get density and heat into the charge but still times the engine with spark. This has the advantage of not requiring any sort of precise injection system, whether mechanical or air, and can 'run all day on the smell of an oily rag' on nonvolatile fuel of crappy quality. One notes that some of the 'vaporizing carburetors' that ultimately culminated in the Fish "200mpg" device beloved of conspiracy theorists, would be a 'natural' to use exhaust or cooling-jacket heat to warm things up to the appropriate induction charge density.
Most things using this engine type would be hard to get to the speed where ram air would produce 'supercharging', and the overall contribution to charge density might be slight. However, I refer 'dude to the Franklin Supercharged Airman Twelve, which channeled some of the air-cooled engine's cooling air through ducts at speed for putative thermodynamic benefits...
Overmod To my knowledge the Ingersoll-Rand switchers used compression ignition, although I don't remember offhand if direct or indirect injection.
To my knowledge the Ingersoll-Rand switchers used compression ignition, although I don't remember offhand if direct or indirect injection.
IIRC, the I-R engines were direct injection. One notable detail of the I-R fuel injection pumps was that tolerances of the injector plunger and cylinder were such that the plunger needed a coat of diesel fuel to slide in the corresponding cylinder.
The Cummins engine in my 1991 Dodge had strip heaters in the intake manifold for aid in cold starting. Having said that, I don't remember seeing any indication that a locomotive engine was so equipped. I recall that nuclear plant back-up diesel generators are typical kept with the coolant at 120F or so to allow for quick starts and rapid loading.
Erik_MagOne notable detail of the I-R fuel injection pumps was that tolerances of the injector plunger and cylinder were such that the plunger needed a coat of diesel fuel to slide in the corresponding cylinder.
To my knowledge all the early jerk pump injectors were like that. The father of my best friend in high school had been a mechanic on 567s in WWII and he noted that you couldn't assemble the injector if there was a fingerprint on it.
Among the fun features of the Ford 6.0L injectors was that they were provided with a DLC ('diamond-like coating') to reduce wear from ULSD. If the fuel flow was impeded, as for example 'running out of fuel', the injectors continued to operate with high-pressure oil actuation, and would almost promptly ruin the bores... necessitating a rebuild or new injectors each time.
I don't think the situation on the 1994 6.5TD, which had one of the early Stanadyne 'electronic' injection pumps and pop injectors, was as serious, but the common word in the diesel community was to use Stanadyne additive regularly to prevent wear damage.
I don't remember seeing any indication that a locomotive engine was so equipped. I recall that nuclear plant back-up diesel generators are typical kept with the coolant at 120F or so to allow for quick starts and rapid loading.
My trucks all had PLATE oil-pan heaters, and recirculating coolant heating (the kinds of 'plug in' heating with a little coil element inside the pan, or in the block through a core/freeze plug, aren't worth a Campbell's condensed cat crap). There is an interesting approach to pre-lubing that doesn't require an explicit accumulator and pressure valves, which I first encountered from Caterpillar: there is an oil pump on the back of the starter motor, and by disengaging the Bendix drive the starter motor can be run a few seconds to bring up the oil pressure and then quickly clutched in to turn the engine for firing.
The dual-mode-lite study, which envisioned 'straight electric' operation of a convered SD40-2, noted that both coolant and lube heating, whether the engine were isolated or shut down on the turning gear, could be performed with a modified Kim Hotstart. There is a fairly large group of historic-preservation mechanics who have put full prelubing systems on engines like 539Ts that really suffer from oil-pressure concerns.
OvermodOvermod wrote the following post 7 days ago: "Oil-Electric" was a euphemism, like Liberty Cabbage or Liberty Hound, to avoid the G-word context after the Great War. It avoided having to mention the hatable Hun name of the inventor of pure compression ignition.
Well, except that the Dan Patch Lines "oil electrics" were built in 1913, four years before the US entered World War 1 - in fact, it was before the war in Europe had even started. The engine used to create electricity wasn't a diesel.
BTW - odd fact, although Rudolf Diesel's parents were German, Rudolf was born in Paris, and lived in France and England growing up - he didn't live in Germany until he was 12.
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