Diesels & altitude

[Overmod]

bronco, I'd always thought that the principal reason for the elimination of the Roots blowers on the turbo EMD engines was system cost. But remember that a Roots, being a positive-displacement blower with very fine internal clearance between the rotors, is only going to pass a given volume per minute, with that volume being determined entirely by what the drive gears -- and the crank rpm -- are providing. Meanwhile, the turbo boost on these big, slow engines is very peaky, with proportionally higher amounts coming on only in the very highest run settings. (Randy Stahl can tell you much better than I can exactly where the boost comes up to meaningful numbers). The point here is that the only effect the turbo would have when feeding through the Roots would be to pressurize the air, increasing its density, at the entrance to the blower -- and I think this would produce more back-pressure than necessary, not exactly the thing you want for good clean scavenging on a two-stroke diesel of this design, precisely at a time when what you most want is no restrictions in the intake tract...

Personally, I think 763/1470 out of a built 6BT is conservative. Last I looked, even the for-publication numbers of some of the Enterprise engines were north of 1100 nominal hp, and the more successful competitors in pulls aren't saying... This is NOT a power rating you're likely to be able to get out of a 6.0 or Duramax without re-inventing the grenade... among other things, aluminum heads no matter how you try to cool them won't take the EGTs as well. I've been waiting several years now to see a PowerStroke (or Duramax) version of that 240-mph Cummins-powered Dakota (or whatever the small-body pickup was) -- surely there are some 200-mph-plus Ford diesels running around out there (probably in the offroad-racing world), but I haven't yet seen any...

Not that you can't make pretty good power out of the 7.3, though. Diesel Dynamics put one in an Excursion for one of the aftermarket-equipment folks... I don't remember who, but adrianspeeder probably knows... and even with all the silly bars and roof racks and stuff increasing the curb weight, the thing ran something like a 12.7 quarter at 127mph (I invite someone with the exact figures to provide them). I think that's reasonable performance by anyone's standards...

[rvos1979]

QUOTE: Originally posted by adrianspeeder

QUOTE: Originally posted by jwalpacific

Of course it would be impossible to make a 9 bearinf V-8, and I am well aware that locomotive V-s use "common" or paired mains. I was merely pointing out that the crankshaftin the IH v-8, as manufactured, would not accept a greater amount of turbo boost without failure. Therefore, the Cummins equipped Dodge would be easier to set to overcome altitude loss of natural air density.

I sniff a cornbinder hater. Perhaps he hasn't heard of every frikin powerstroker like me that mod the heck out of our fords and get waaaay over stock boost and never snapped a rod. It will take a lot more than just high boost to brake something on any engine. Lots of air is useless if there ain't enough fuel to use it. Next on my list is propane injection to get that ford up to the modded cummins slayer level. My V8 will whooop your I6... [:D][:D][:D]

And what is with this anti intercooler stuff? The increased heat from compressed air will offset increased boost. The only thing an intercooler hurts is turbo lag time. That can be solved with a heavier foot when reving before dumping a clutch, or a higher stall torque converter for the slushbox fans.

Adrianspeeder

Adrian,

I've got nothing against IH diesels, I'm partial to the DT466 myself, I'm just not real thrilled with the HEUI setup in the DT444E (7.3 Powerstroke). I can't say how the six liter engines are, though, never played with them yet (I'm VERY interested in that variable geometry turbo, though, the turbo kit from Banks sounds like it will eliminate lag).

I was digging through my old Mopar magazines, got some numbers for you to shoot for. This was done on a chassis dyno, a guy at the Carlisle Nationals in PA made 763HP and 1470ft/lb torque with his '01 Cummins ISB.

I'm reminded of an older Ram ad:

"It's what you get when you cross a diesel locomotive with a really nice sofa."

Randy

[broncoman]

Overmod,

I probably didn't word my question right. I agree with what you said. My question was more towards why EMD didn't just keep the roots charger and add a turbo instead of designing a new turbo that would incorporate a way to produce that boost mechanically until the exhaust was such to run it as a normal. In my profession I have seen 16v-149 gensets that have a turbo blowing through the roots blower. I was assuming this is how the marine engines do it also. Most of the time I am learning to repair 6v and 8v 53s and 92s. I was curious as to why EMD didn't go this route and instead designed a turbo to do both jobs. It seems a better deal in that you have one item doing two jobs. From what I have read on other posts the turbo assembly is only good for about 5 years. I didn't know if this was a result from it having to do both jobs or was this due to environment?
So back to the question stated better; why did EMD go this way instead of Detroit Diesels way?

Randy?

[Overmod]

bronc, there are some very good accounts on the Web about the EMD overrunning turbo.

Basically, there just isn't enough exhaust volume at the lower runs to produce spin on a turbo of 'economical' best size for full power. You might get around this with multiple small turbos, but that's not particularly economical either in terms of equipment or maintenance. What EMD did was recognize that you'd get better boost off a mechanical drive at low rpm, phasing over to turbo boost at high rpm, and eliminate essentially 100% of the turbo lag problem at the same time.

If there's a problem with EMD's implementation, it's in the original design of the overrunning clutch. Randy and some of the other wise diesel heads on this forum can tell you how they go bad, and probably how they could best be improved.

One point about the Roots blower as fitted to 567s (and 645s a la GP38) is that they're positive-displacement blowers -- developing air movement and pressure even at comparatively low speed, and increasing in proportion to driving rpm -- as opposed to things like centrifugal compressors (which most turbos effectively are) which require relatively high rpm to make effective boost. Note that a gear-driven turbo is an intermediate stage in this respect, which allows you to get rid of separate scavenge blowers if you want without sacrificing the advantages of turbo boost at high engine output...

[broncoman]

Does anyone know the reasoning that EMD decided to use a gear driven/exhaust overdriven turbo instead of just adding a turbo to the existing supercharger like. Great story by Mr. Strack.
On a diesel, do you get an increase in HP with increases in compression ratios. If so had any railroads experimented with this for units who spent time mainly in higher areas to compensate?

Dave

[Anonymous]

QUOTE: Originally posted by Leon Silverman

To answer up829 question about variable valve timing; variable valve timing will not supplant the benefits of a larger turbo, which presumably would also provide a higher boost. Cylinder air has mass. This means it also has inertia and momentum. Increasing valve timing (duration and overlap) allows an engine to develop more power because it can breathe easier at high rpms. The increased valve timing gives the cylinder air more time to exit the cylinder by givng the air mass more time to get moving out of the cylinder ),overcoming its' inertia. The increased overlap (simultaneous opening of exhaust and intake valves) sucks more fresh air charge into the cylinder due to the siphoning effect of the fast moving exhaust gases. The momentum of the incoming air continues to add mass to the cylinder even after the piston has reached the bottom of its stroke. To take advantage of this, the intake valves are not closed until after the piston starts to move up again. This effect is usually not noticed until an engine reaches or exceeds about 3,000 rpm.
The downside of this effect is that when use a cam timing that develops high horsepower at high rpms, you have a relatively unresponsive engine at low speeds) off the line. Conversely, an engine set up to hit its' torque peak at low rpms will be very responsive in stop and go traffic but is weak passing cars at highway speeds.
Variable Valve timing gives you the best of both worlds . You wind up with an engine that is responsive at both high and low rpms.
Diesel engines utilize a heavy construction in order to withstand the high compression ratios. This heavy construction limits the maximum rpms that the engine can safely operate at. Diesel engines develop a lot of torque at low rpm because they are generally large displacement engines. Changing valve timing so that a diesel can operate at higher rpms is a waste of time unless you can also reduce the weight of the reciprocating masses (pistons, crankshafts, and connecting rods) to permit the higher rpms. Increasing turbo boost can increase torque output and horsepower without requiring the engine to operate at a higher rpm.
As I stated before, the horsepower boost from free breathing usually starts at around 3,000 rpm. Since locomotive diesels operate at a maximum of 1000 to1200 rpm, increased horsepower requires high boost pressures. Valve timing will not do it.

I was thinking more along the lines that the increased boost in Run 8 might decrease the scavenge time beyond the reduction provided by the modest increase in RPM. This would depend on the difference in boost between Run 1 and Run 8 and whether these engines are already optimized for Run 8 or compromised in order to allow cold startup. If I understand these engines correctly, the incoming charge is not compressed in the crankcase like a 2 stroke gasoline engine, instead a blower or turbo-supercharger is required to scavenge the cylinders.

[adrianspeeder]

QUOTE: Originally posted by jwalpacific

Of course it would be impossible to make a 9 bearinf V-8, and I am well aware that locomotive V-s use "common" or paired mains. I was merely pointing out that the crankshaftin the IH v-8, as manufactured, would not accept a greater amount of turbo boost without failure. Therefore, the Cummins equipped Dodge would be easier to set to overcome altitude loss of natural air density.

I sniff a cornbinder hater. Perhaps he hasn't heard of every frikin powerstroker like me that mod the heck out of our fords and get waaaay over stock boost and never snapped a rod. It will take a lot more than just high boost to brake something on any engine. Lots of air is useless if there ain't enough fuel to use it. Next on my list is propane injection to get that ford up to the modded cummins slayer level. My V8 will whooop your I6... [:D][:D][:D]

And what is with this anti intercooler stuff? The increased heat from compressed air will offset increased boost. The only thing an intercooler hurts is turbo lag time. That can be solved with a heavier foot when reving before dumping a clutch, or a higher stall torque converter for the slushbox fans.

Adrianspeeder

[Anonymous]

QUOTE: Originally posted by jchnhtfd

At the risk of starting another hare -- there is a seemingly unrelated issue involved in high altitude operations, which is one of the major reasons why mudchicken sees units under test: cooling. Without bothering with all the details, suffice it to say that a radiator of a given size can't cool an engine as effectively at high altitude as at sea level, all other things being equal, and most manufacturers worry that maybe, just maybe, at full power things may get too warm... Not usually a problem in automotive applications (automotive/truck radiators are moderately to hilariously oversize, in most applications) but very much a problem with a railway engine.

They aint big enough. You will learn this when you try to cross the dead valley to the western areas of Nevada in summer. My problem with older cars and some trucks was actually radiators that were too small and did not contain enough evaporative area to get the heat out.

There are two kinds of cooling. RAM air cooling is helpful when a vehicle is at speed the pressure of the air flowing into the vehicle's front and the "pass thru"

The other form of cooling is simple radiating. This happens when you are in hot traffic stuck idling at gridlock stop and go. All vehicles have a limit.

Some of the aircraft engines such as the Pratt and Whitney are marvelous in not needing radiators other than what air cooling already provides. Although I venture that they operate in atmosphere that is quite freezing and that helps alot.

[Anonymous]

In trucking we had computers on our engines that understood what the "outside" was like and understood what needed to be done to create the power.

When I came thru Eisenhower (over 12,000 feet) in colorado I did not detect any "driveability" issues with the Cummins I had under my hood. Even though I was suffering from oxygen problems being that high up from sea level. (Dont smoke like I did for many years)

I have flown in private planes at 13,000 feet and can attest to the loss in performance both at the wing and engine. Never mind the threat of sleep that kills. (Hypoxia? -spelling)

There is always a limit somewhere at a point above land on the earth that a desiel will fail to run.

This remains true for all "Airbreathing" engines and people.

Large desiels are my personal favorites when it gets VERY cold. You need to keep it lit and the fuel warm. As long you have warm fuel and able to keep it lit then you will survive.

Since my trucking days in the rockies are over, I am quite content to remain near sea level. On a recent flight on southwest I could tell the cabin pressure was "Higher" in altitude than what I am accustomed to being at.

[Anonymous]

Of course it would be impossible to make a 9 bearinf V-8, and I am well aware that locomotive V-s use "common" or paired mains. I was merely pointing out that the crankshaftin the IH v-8, as manufactured, would not accept a greater amount of turbo boost without failure. Therefore, the Cummins equipped Dodge would be easier to set to overcome altitude loss of natural air density.

[Anonymous]

A rough rule of thumb for piston engines is a 7% loss in hp for every 1000 feet gain in altitude. For instance, your 300 hp normally aspirated truck drops down to about 200 hp at 5,000 feet. At 10,000 feet.... Well, it's gasping for air, right?

A turbo CAN negate this, if it has a gate on it that normally liimits the pressure boost under normal altitude operation. At high altitude the turbo would then be used at 100% of its capacity to keep things humming along. If that 4400 hp locomotive normally has 30% of the turbo output bypassed, then at roughly 5,000 feet the bypass would close down and you'd still get 4400 hp out of it. At 7,000 feet you'd get maybe a 15% reduction in power.

I personally don't know how the locomotives have their turbos set up. More turbo can give you better performance at altitude, but costs more and takes up more space.

Mark in Utah

[Leon Silverman]

To answer up829 question about variable valve timing; variable valve timing will not supplant the benefits of a larger turbo, which presumably would also provide a higher boost. Cylinder air has mass. This means it also has inertia and momentum. Increasing valve timing (duration and overlap) allows an engine to develop more power because it can breathe easier at high rpms. The increased valve timing gives the cylinder air more time to exit the cylinder by givng the air mass more time to get moving out of the cylinder ),overcoming its' inertia. The increased overlap (simultaneous opening of exhaust and intake valves) sucks more fresh air charge into the cylinder due to the siphoning effect of the fast moving exhaust gases. The momentum of the incoming air continues to add mass to the cylinder even after the piston has reached the bottom of its stroke. To take advantage of this, the intake valves are not closed until after the piston starts to move up again. This effect is usually not noticed until an engine reaches or exceeds about 3,000 rpm.
The downside of this effect is that when use a cam timing that develops high horsepower at high rpms, you have a relatively unresponsive engine at low speeds) off the line. Conversely, an engine set up to hit its' torque peak at low rpms will be very responsive in stop and go traffic but is weak passing cars at highway speeds.
Variable Valve timing gives you the best of both worlds . You wind up with an engine that is responsive at both high and low rpms.
Diesel engines utilize a heavy construction in order to withstand the high compression ratios. This heavy construction limits the maximum rpms that the engine can safely operate at. Diesel engines develop a lot of torque at low rpm because they are generally large displacement engines. Changing valve timing so that a diesel can operate at higher rpms is a waste of time unless you can also reduce the weight of the reciprocating masses (pistons, crankshafts, and connecting rods) to permit the higher rpms. Increasing turbo boost can increase torque output and horsepower without requiring the engine to operate at a higher rpm.
As I stated before, the horsepower boost from free breathing usually starts at around 3,000 rpm. Since locomotive diesels operate at a maximum of 1000 to1200 rpm, increased horsepower requires high boost pressures. Valve timing will not do it.

[kenneo]

QUOTE: Originally posted by jchnhtfd

At the risk of starting another hare -- there is a seemingly unrelated issue involved in high altitude operations, which is one of the major reasons why mudchicken sees units under test: cooling. Without bothering with all the details, suffice it to say that a radiator of a given size can't cool an engine as effectively at high altitude as at sea level, all other things being equal, and most manufacturers worry that maybe, just maybe, at full power things may get too warm... Not usually a problem in automotive applications (automotive/truck radiators are moderately to hilariously oversize, in most applications) but very much a problem with a railway engine.

That is the reason that SP had EMD make the Tunnel Motors. After two SD 40/45's transit a tunnel or snow/rock sheds in the Cascades or Sierras, the units behind the lead two start to overheat. Then they shut down and this causes all sorts of bad things to start happening. And this is happening at altitudes 1/2 as high as Rollins and Winter Park. Tunnel Motors have a larger radiator as well as air intakes down where the air is cooler.

[jchnhtfd]

At the risk of starting another hare -- there is a seemingly unrelated issue involved in high altitude operations, which is one of the major reasons why mudchicken sees units under test: cooling. Without bothering with all the details, suffice it to say that a radiator of a given size can't cool an engine as effectively at high altitude as at sea level, all other things being equal, and most manufacturers worry that maybe, just maybe, at full power things may get too warm... Not usually a problem in automotive applications (automotive/truck radiators are moderately to hilariously oversize, in most applications) but very much a problem with a railway engine.

[Anonymous]

In 2 stroke diesels, some of the boost is used to scavenge the cylinders. At low rpm/low boost, the intake ports and exhaust valves need to be open long enough to do this. Would variable exhaust valve timing be more beneficial in achieving higher cylinder pressures at full power/high boost than a larger turbo? Do any 2 stroke diesels do this?

[Overmod]

Mr. Silverman would be correct on an engine not employing compression ignition. Not intercooling at high boost on spark-ignition gas engines, for example, could easily be a ticket to interesting detonation. Diesels are a bit different in that you can recover the compression energy in the subsequent power stroke up to comparatively high nominal boost pressure, and so long as you have a stoichiometric amount of oxygen in the charge air mass, and your rings, etc. can take it, the absolute mass of charge air isn't as significant (and, in fact, higher mass can become detrimental at high flow rates (and can contribute to stronger torque peaks in the stroke). Remember, the part of the heat energy that makes a difference in these engines manifests itself as pressure; higher pressure 'in' will produce higher pressure out, especially on engines with good ceramic components and thermal coatings; you're getting the additional boost pressure 'free' through the magic of heat drop through the turbocharging system at the price of proportionally low back pressure in the exhaust.

Remember that I'm not talking about the peak power you can squeeze out of the engine, either -- for that, you'll benefit from intercooling because (as he indicates) you can at least in theory provide a denser charge at any given manifold pressure if the charge is cooled (either before or after the injection of the fuel).

"In terms of thermal efficiency" any time you are using energy to do compression, and then subsequently throwing the heat away, you're using energy derived from the fuel to no purpose. If you run the numbers, you'll find that proportionally you're using more fuel (measured as specific fuel consumption per hp/hr or similar units) for an intercooled engine. The advantages of intercooling lie in other places: for instance, you can often use a smaller and lighter engine to make a specific required horsepower, lightening the vehicle beyond what the added mass of the intercooler and pipes requires.

An interesting point is that pressure goes up seemingly out of proportion to temperature, which is why you see Cummins boost up there in the 50 to 60lb range even on streetable trucks -- if you look at the mass flow at the higher pressure, Mr. Silverman is again correct in noting that an intercooled charge at a lower pressure will allow the same, or higher, horsepower output from an engine of given displacement. Indeed, to get very high horsepower output out of a given engine, at some point it becomes imperative to use *some* intercooling on the charge air.

As another aside, it might be interesting to speculate on whether a diesel engine running at high altitude, pressure-turbocharged *with minimal heat loss* to nominal sea-level MAP, would actually produce a bit MORE power (net of the additional turbo action) since there is lower back pressure on the exhaust, and that will in turn allow a bit better heat drop (and hence energy recovery) across the turbo. (One might note by analogy that steam locomotives can perform much better at high altitude than at sea level -- their exhaust being freer, and the required higher airflow for combustion being easily assured up to quite high altitudes.) What you would expect to see, however, is a VERY large turbo wheel and intake plenum; something which if used as the only turbocharger would make 244 smoke look puny! (And cost way, way too much for something used in the ranges closer to sea level...)

[mudchicken]

EMD and GE still test the new protoype units at Raton Pass (Elev 7800+), Pueblo AAR/TTC (Elev 5000'+/-), Winter Park (Moffat Tunnel) and Palmer Lake (Monument Hill, Elev 7200+) on a regular basis. The new EMD's still appear on a regular basis for high altitude tests with EMD's Test Car No. 800...........On the older engines, rack setting helped with the power curve / combustion issue as well.

(At La Junta, Pueblo or Denver on ATSF it was rare to see anything without a turbo used as power.....GP38's were rare, GP 39's were common. CF7's and GP-7/9's were unusual to see, GP20R's were everywhere in Yard service. (Exception was GP9 slug mother 1312 and slug 109 at Pueblo and later at La Junta ...later , in the 1990's we saw herds of demoted GP-30m's, GP35R's and B23-7's in yard service)

[banghead][banghead][banghead]

[Leon Silverman]

I question Overmod's statement regarding intercooling. The aim of turbocharging is to increase the MASS of air getting into the cylinder. Increasing the pressure on air raises its temperature. Raising the temperature of a gas decreases its' density. Using an intercooler increases the density of the incoming air, in essense turning the single stage turbocharger into a two stage compressor. The result is that an intercooler puts a greater mass of air into the cylinders than the turbocharger would otherwise provide while operating at the same boost pressure.
Adding an intercooler may not increase the gas mileage of a vehicle because developing more horsepower means burning more fuel. However, in terms of thermal efficiency, which measures the the amount of power developed per unit of fuel burned, the effect is beneficial. You are litterally getting more bang for your fuel buck. The only downside is that higher fuel efficiency results from higher pressures and temperatures being developed inside the cylInders (a.k.a. BMEP). This means that the engine parts are subjected to higher stresses and may have to be beefed up.

[Anonymous]

Don't forget that alot of high altitude operations also include many sharp curves and tunnels, not to mention steep grades. D.&R.G.W.'s & S.P.'s SD-40t2 & SD-45t2's were splendid power in that environment. Walking your train in Moffat with 30 minutes of air in your s.b.a. isn't fun.

[jchnhtfd]

Just for the sake of laughs on the main bearing questions above... radial aircraft engines do some amazing things! At the far extreme end -- the P&W 4360 Wasp Major produced up to 4,000 HP on 5 main bearings, 4 crank throws! (28 cylinders)...

[passengerfan]

The poor turbochargers were the reson for the failure of the Budd built Rio Grande Prospectors. They had a great deal of difficulty breathing at the high altitudes found on the Rio Grande mainline. If the two two car trains had been operated on almost any other railroad in America they probably would have been extrememly successful. The Hercules diesels they were equipped with were very successful. It was the small turbos that were the downfall of the original Prospectors.

[Overmod]

Increase of what?

Compression ratio doesn't change when you increase the volume compressed through the turbo to compensate for high altitude/low density. All you're doing is compressing a larger volume of air that was at a lower pressure, so the MAP would be reading what it would "see" in normal operation. Of course, it would help to have a larger wheel on the turbo's compressor, so you move more air rather than reach higher final pressure... the place to put this larger wheel is on the secondary turbine in a sequential setup, so you get the larger mass flow going into the primary (which would be the one with the fancy variable vanes).

Yes, you can use twins on a PowerStroke or Duramax. Granted, you can boost a Cummins 6BT more extravagantly -- but is the difference between 700hp and 1100hp important in this context???

Oh, yes: exactly how would you propose to make a V-8 that has nine main bearings without forging the *** crank so long, and making the engine so long, that it runs like a dog? The GM 2-stroke locomotive diesels all use common journals for pairs of cylinders (fork 'n blade on the 567s) and I don't think anyone questions that they produce more unit power than any feeble little big-cam Cummins or tiny Cat 3206... It's the SIZE of your mains -- the journal diameter and the area of the bearings -- that determines how much "compression" you can run without compromising your engine life. The GM 6.5TD, for example, is limited by the crank strength, not the bearings; the crank fails in torsion, which has little to do with the number of mains.

I've said it before, and I'll say it again, if you don't care about NOx you want to get as much boost into a diesel as you can possibly manage, but NOT intercool the charge air. Naturally you need really strong rotating parts, and stout mains, block, etc. to make this trick work right. You get effectively all the energy used to compress the hot air back during the power stroke, so the engine runs with much more jerk, but higher thermal and mechanical efficiency. Intercooling throws away energy!

[Anonymous]

I would like to know the brand of diesel truck in the original question. If it is a Ford with the International v-8, this engine suffers from the same problem that has plauged every v-8 made by International-running 8 cylinders with only 5 main bearings, making the crankshaft too weak to handle the increase of compression ratio that would come from using a turbocharger big enough to supply the air required to compensate for the altitude density loss. If the truck in question is a Dodge with the cummins inline 6, I think that a dealer could make an adjustment. I know nothing about GM Duramax, but if it is also a v-8 , the crankshaft could again be the limiting factor. When International tried to produce a v-8 farm tractor, the 1468, the farmers tried to turbocharge this naturally aspirated engine with crankshaft failure following not to far behind.

[SSW9389]

Union Pacific turbocharged over 30 GP9s before the first GP20 was built. See my previous post on this thread for reference by Don Strack. The UP experimentation led to the EMD's own turbocharger equipped units: SD24 and GP20. First Turbo GP9 was in 12/55! [:)]

QUOTE: Originally posted by kenneo

The DRGW milled out the air intake ports of its Roots equipped 567's to solve this problem. This would be the so-called "normally aspirated" 567 model engines prior to the GP 20 which was the first EMD I know of to have a turbo.

[kenneo]

The DRGW milled out the air intake ports of its Roots equipped 567's to solve this problem. This would be the so-called "normally aspirated" 567 model engines prior to the GP 20 which was the first EMD I know of to have a turbo.

[rvos1979]

QUOTE: Originally posted by selector

Actually, you can compress cold air, and I know this because that is the only way to get diesel-equipped tractors running up in the arctic. The slow crank is more likely a function of crankcase oil viscosity and/or battery condition. Of course, spray ether helps, but if you have enough juice, you just crank the diesel over until the compression warms up the piston top and cylinder head. The fuel is especially formulated for arctic ops, so atomization is not an issue. Once the cylinders get hot enough, they fire.

No one said it was pretty, but it works.

Just don't shoot ether into an engine with an intake manifold heater, unless you want to replace the manifold......

Randy

[selector]

Actually, you can compress cold air, and I know this because that is the only way to get diesel-equipped tractors running up in the arctic. The slow crank is more likely a function of crankcase oil viscosity and/or battery condition. Of course, spray ether helps, but if you have enough juice, you just crank the diesel over until the compression warms up the piston top and cylinder head. The fuel is especially formulated for arctic ops, so atomization is not an issue. Once the cylinders get hot enough, they fire.

No one said it was pretty, but it works.

[adrianspeeder]

Have no fear.... Adrian"diesel"speeder is here...

What is the truck in question?

Adrianspeeder

[espeefoamer]

Diesel HP loss at high altitudes was the reason that the Colorado & Southern kept a steam engine on the Leadville to Climaxc branch until Oct. 1962.