Can this really happen?

Page 2 of 2  
I've owned 2 240D's with manual transmissions and I live on a good sized hill. If I had only used the car during the day the battery would have been unnecessary.


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
WAIT A MINUTE where is the starting voltage coming from I thought diesels started from a electrically heated glow plug. I know NOTHING about diesels but, it seems to me, starting an engine with a compression ratio of 400 psi, should be harder than my old 60' Ford Falcon stick, unless there is some sort of piezo electric effect. Are you saying pushing a cold diesel, with no battery, down a sloped driveway would compress the fuel enough for it to combust? getouttahere!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I've heard that diesels don't even use glow plugs anymore. I'm not exactly sure what they do, but I think the timing is either advanced or retarded during a cold start.
Robert

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Robert Calvert wrote:

Nope, direct injection diesels just have a lot higher compression ratio than prechamber/glow-plug diesels, and can start without aid because the air in the cylinders gets much much hotter just from compression. Sometimes a heater is added in the intake plumbing (eg. Dodge Ram) so that the driver doesn't notice longer crank times at lower temps, but its not really necessary. Just a luxury.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@webtv.net (r parris) wrote:

Glow-plugs make starting a cold diesel easier, but they *ARE NOT* vital to the process - Case in point: an 80-something F350 diesel that we use for grunt work here on the ranch. Its glow-plugs (and in fact, the entire wiring harness that used to power the glow plugs) are toasted, and have been for years. Result: Y'gotta crank it and crank it and crank it and then crank it some more, and perhaps even crank it a little bit more than that before it fires on the first start of the day, but it runs just fine. Once there's some residual heat in the block/heads from the first run of the day, you can shut it down, and it will restart so quick you'd be left totally clueless about the fact that the glow-plugs don't work.

"Your falcon must have a timing issue" is about all I can say. Gas engines with a stick behind 'em are, in general, kiddy-play to push-start unless the timing is off. As a prime example, my '82 Mazda 626 push-starts in reverse with three feet or less of backwards roll, or in third with about 8-10 feet of forward roll - first time, every time, no sweat at all.

That's *EXACTLY* what's being said. The key is getting the air in the cylinder compressed quickly enough to produce an in-cylinder temperature that's at or above the flash-point of the fuel. Glow-plugs (and the associated wiring/power supply) make the process easier by raising the head/block temperature, which in turn raises the temperature of the air charge in the cylinder, but they *ARE NOT* mandatory. The same effect can be achieved (and in fact, this is specifically recommended in some cases) by playing a blowtorch on the head for a while before trying to start the engine.

Lemme give the old diesel a push to get it rolling down the hill, and I'm gone... :)
Fact: Some heavy equipment with diesel engines, like 2 of the 3 ancient (30s? 40s? 50s? They truly are ancient beasts) dozers our hay grower uses for farming his rice, have *NO* electrical system whatsoever on them. *NOTHING* electrical. They don't have a single wire, no alternator, no generator, no battery, no cord to plug into 110 or 220, or any other kind of electrical stuff on the main engine. They DO have a "pony motor" alongside, which, in this particular case, runs on gas (and as such, has the requisite electrical ignition system to make a spark) and starts by way of pure human power - either hand-crank like an old Model T, or pull-start like a lawn mower, depending on which of the two you're trying to fire up. Neither one has anything that even resembles a glow-plug, although I have seen cases where the exhaust from the pony is routed through galleries in, or ductwork around, the head to perform exactly the same function glow-plugs would serve. To start either one of these two Cats, you start the pony, by either cranking or pulling as needed, get it running happy, pull a lever, and the pony spins the main engine until it fires. Then you crawl down on the track, shut down the pony, and go about the day's work.
Alternatively, there are the "air-start" versions - they start from compressed air supplied by either a pressure tank that they pump up while they're running, or an external air compressor. Again, not a wire, battery, alternator, or glow-plug to be seen anywhere on them.
In summary: With a diesel that isn't computer-controlled, electricity, in any form, is *COMPLETELY* optional. Nothing about them requires anything electrical to be attached for them to run, although having glow-plugs does tend to make starting them for the first time each day a fair bit easier.
--
Don Bruder - snipped-for-privacy@sonic.net <--- Preferred Email - SpamAssassinated.
Hate SPAM? See <http://www.spamassassin.org for some seriously great info.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Learn something every day! THIS is why I love this site ! Gone shopping for an '87 to '91 5cylinder turbo diesel (make sure the ac works)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

it and then crank it some more, and perhaps...<<<
This can ruin the engine. Get enough unburned liquid into the tiny compression chamber of a 20:1 engine and eventually something will happen. "Something" may either be starting, or a bent connecting rod, or a blown head gasket.
Bill Ditmire Ditmire Motorworks,Inc. 425 White Horse Pike Absecon,NJ 08201 http://www.ditmire.com 609-641-3392
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

automatics that can be push started....much longer distance is required than manual,though.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I was told, in life boats they use diesel engines started by hand.
Can anybody confirm that?
Timothy

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
True, Also while in the army (British) I used to hand crank old generator sets 7 & 12.5 Kva, summer time that is, winter time put an old oily rag in the air filter place and set it alight, then crank her good. These did use a pre-compression lever, to relieve the compression of the engine untill you got up to speed and let it go. They usually started with a big black cloud of exhaust and took a few minutes to get up to speed, but they did run for ever. Colin D.
: > After listening to last weeks puzzler, and hearing the answer on Car Talk, : I : > was wondering if a diesel engined car could really run with a dead : > electrical system. : > : > http://cartalk.cars.com/Radio/Show/Audio/200350/RA/s05.ram : > : > Even though it is true that a diesel has no ignition system, I have always : > assumed that a diesel still used some kind of electrically operated : control : > system for the fuel pump. After all, even diesel cars have what would be : > regarded as an "ignition switch" in a gas powered car. Even though I doubt : > that a modern diesel could run without electrical, I suppose it is : possible : > that older diesels had some kind of mechanical linkage that controlled the : > fuel pump. Any comments? : > : > Robert : > : > : :
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yes, this can happen. In fact, it happened today - the negative terminal cable came loose and off of the battery terminal, and as such I lost all electrical functions - no radio, lights, signals, wipers, NOTHING. But I still had power steering, brakes, and the engine ran without complaint. Scary stuff.
: After listening to last weeks puzzler, and hearing the answer on Car Talk, I : was wondering if a diesel engined car could really run with a dead : electrical system.
: http://cartalk.cars.com/Radio/Show/Audio/200350/RA/s05.ram
: Even though it is true that a diesel has no ignition system, I have always : assumed that a diesel still used some kind of electrically operated control : system for the fuel pump. After all, even diesel cars have what would be : regarded as an "ignition switch" in a gas powered car. Even though I doubt : that a modern diesel could run without electrical, I suppose it is possible : that older diesels had some kind of mechanical linkage that controlled the : fuel pump. Any comments?
: Robert
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

of course, for earlier engines. my dad put in a W115 300D engine into a Ford Econoline, the only electrical thing is the starter. 150,000KM so far and no problems
cp
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I believe youi have the aluminum head, so if you can't find any leaks then you probably have a warped head leaking coolant into the combusion chamber, which burns it out so hot you don't see the moisture in the exhaust fumes. I had a similar problem with a 242 Volvo, I pulled the head off, got a fine tooth flat file, and carefully shaved the high spots off the head with the flat file. (For all you naysayers, this technique will not gouge the surface of the head). Then I put it back together with a new head gasket, tune up and so on and my water usage problem was solved with many, many more miles on the engine.
--Geoff '84 300D
Robert Calvert wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
i would suggest you site www.howstuffworks.com u can find alot of info bout diesel engines and all other engineering stuff...its quite ql...

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Absolutely no electrical power is needed for a diesel engine to work, as long as there is fuel, air and a way to start the engine. Modern diesel use an electrical pump to transfer fuel to the high pressure injection pump, but it is not really needed. Same goes for control system of the HP pump. Engine, like in a modern pick up, will have a electrical motor to control the fuel HP pump, but it is strictly an accessory, and a replacement for a throttle cable / also an easy way to meet emissions, because it can be controlled by a computer. When you turn off the key on a car, you de-activate a fuel shut off solenoid. Convenient but not necessary for the engine operation.
Cheers,
-- Martin Leduc
Martin's Marine Engineering Page www.dieselduck.net

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I used to drive a dumper truck which had a single cylinder diesel engine fed by gravity from fuel tank. You had to crank it relly quickly while keeping a big valve in the head open then suddenly close the valve to allow the thing to work. No electricity anywhere and no fuel pump either.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The statement in the Puzzler set the time as 1974 and said that the car was "about 14 years old and had fins". The ALT light came on when the belt broke. I agree that the engine would run until turned off. Where I think the puzzler was wrong is that in 1960 MBs had generators not alternators if my memory serves. I had a 1960 190C -not a diesel- but I think there was a 190D and there may have been a 240D.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Robert Calvert wrote:

Only relatively recent diesels with things like computer-controlled injection or HEUI (hydraulically activated electronically-controlled unit injection) need electrical power to run. Many older ones did have an electrical solenoid to hold the fuel supply open, but other than that would run with no electrical power. Most older machinery diesels had a mechanical cable to shut down fuel and could run with absolutely zero electrical power.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.