Cold start failure

[skyhook]

Still wrong. Heat from compression is required for a diesel to run. Without it, they won't run....period.

This, I agree with,
Of course heat is generated upon compression to start a diesel,
but a cold engine block "will not" rob this heat and prevent it from starting, that is false.
It may make it more difficult, but it will start with the three elements I've stated, this I know for a fact.
And I'm saying , "even without glow plugs or pre-heats".
I did say it may need a shot of either to help it along, if needed.

 

[GManBart]

This, I agree with,
Of course heat is generated upon compression to start a diesel,
but a cold engine block "will not" rob this heat and prevent it from starting, that is false.
It may make it more difficult, but it will start with the three elements I've stated, this I know for a fact.
And I'm saying , "even without glow plugs or pre-heats".
I did say it may need a shot of either to help it along, if needed.

Okay, you can disagree with proven facts all you want. If the block/heads/pistons being cold didn't matter, there wouldn't be such things as glow plugs and grid heaters.

Saying that it can make it more difficult to start, but not prevent it from starting is just silly....at some point it will be cold enough that the engine isn't going to start without something additional to create heat.

 

[Danny C]

Okay, you can disagree with proven facts all you want. If the block/heads/pistons being cold didn't matter, there wouldn't be such things as glow plugs and grid heaters.

Saying that it can make it more difficult to start, but not prevent it from starting is just silly....at some point it will be cold enough that the engine isn't going to start without something additional to create heat.

You are correct; once the amount of heat which is absorbed by the engine block and cylinder heads is equal to the heat generated by the compression of the fuel/air mixture, a diesel engine will not start. Actually, that point would be when the heat generated through compression is less that the heat absorbtion rate of the block and cylinder head and lower than the ignition point of diesel.

What is that temperature? I don't know, but it's cold! That is why we add heat to the engine pre-start via intake heaters, glow plugs, block heaters, oil heaters and coolant heaters or use a fuel (ether) that ignites at a lower temperature.

*Edit: Clarified first paragraph: Actually, that point would be when the heat generated through compression is less that the heat absorbtion rate of the block and cylinder head and lower than the ignition point of diesel.

 

[skyhook]

A faster turning engine will create more combustible heat than a slower turning one and will not be affected by the lose that a cold block will remove from it.
Do you at least agree with this....lol
Or am I just being silly again.

 

[jix]

No shots of ether, please. Not in a small diesel engine. Might as well use a shot of nitroglycerine.

 

[jix]

A faster turning engine will create more combustible heat than a slower turning one and will not be affected by the lose that a cold block will remove from it.
Do you at least agree with this....lol
Or am I just being silly again.

Cannot disagree with this fact, given that there is enough compression in the engine to create the required heat for combustion. The cold soaked engine will cool the intaken air, but the peak of compression is so brief as to render that small amount of cooling irrelevant. That is one of the reasons why the engine must be cranked fast and have an intact compression ratio. Having said that, there is a point of cold temperature where the intaken air is just too cold to get hot enough to initiate combustion, hence the need for intake air heaters and glow plugs, plus arctic diesel fuel. I have started small diesel engines in new condition at 50 below celcius using only glow plugs. At suych temperature extremes crankcase oil can become a solid. If so, that will destroy the engine when it is cranked, so the oil pan must first be warmed a bit by direct heat from some independant source, such as a torch. Any oil will freeze solid at the temperature of dry ice. Ask me how I know.

 

[Danny C]

A faster turning engine will create more combustible heat than a slower turning one and will not be affected by the lose that a cold block will remove from it.
Do you at least agree with this....lol
Or am I just being silly again.

Skyhook, at Absolute Zero (0 Kelvin), there is no heat energy and at that temperature, no amount of turning a diesel engine at any speed within normal operating parameters (RPM) will generate enough heat for it to start as the heat generated would be lost to the environment. #1 Diesel won't auotignight until it reaches 177C (350.6F).

Since we aren't likely to experience Absolute Zero, in practical terms such as the OP stated (-22F), A diesel engine's starter motor (in most cases), on it's own, can't turn an engine fast enough to generate enough heat from compression to start the engine before the battery dies without some sort of aid (extra batteries wired paraell, a battery charger that can input power as fast as a battery is being discharged, intake heaters, glow plugs, block heaters, oil heaters and coolant heaters or use a fuel (ether) that ignites at a lower temperature). But the OP has a block heater which was plugged in and the engine was warm.

I still think his problem is gelled fuel, but then again we haven't heard from him since Sunday evening. We still haven't heard from the OP since Sunday evening. I'd love for him to report back with his findings.

 

[GManBart]

A faster turning engine will create more combustible heat than a slower turning one and will not be affected by the lose that a cold block will remove from it.
Do you at least agree with this....lol
Or am I just being silly again.

The faster turning engine will create more heat, but it will still be affected by heat loss to the cold engine.

Whether it's enough to prevent the engine from starting depends upon a whole bunch of other factors...how cold the engine is, how cold the ambient air is that gets drawn into the engine (and it's density to some degree which will vary with barometric pressure), what treatment is in the fuel, how well the rings and valves seal, etc, etc, etc.

 

[skyhook]

Skyhook, at Absolute Zero (0 Kelvin), there is no heat energy and at that temperature, no amount of turning a diesel engine at any speed within normal operating parameters (RPM) will generate enough heat for it to start as the heat generated would be lost to the environment. #1 Diesel won't auotignight until it reaches 177C (350.6F).

Since we aren't likely to experience Absolute Zero, in practical terms such as the OP stated (-22F), A diesel engine's starter motor (in most cases), on it's own, can't turn an engine fast enough to generate enough heat from compression to start the engine before the battery dies without some sort of aid (extra batteries wired paraell, a battery charger that can input power as fast as a battery is being discharged, intake heaters, glow plugs, block heaters, oil heaters and coolant heaters or use a fuel (ether) that ignites at a lower temperature). But the OP has a block heater which was plugged in and the engine was warm.

I still think his problem is gelled fuel, but then again we haven't heard from him since Sunday evening. We still haven't heard from the OP since Sunday evening. I'd love for him to report back with his findings.

Lets not get side tracked here....
For those of you who aren't aware, Absolute Zero is....

−273.15ｰ on the Celsius scale

−459.67ｰ on the Fahrenheit scale

Given those temps, I myself wouldn't start...

I did say " a strong turning engine" however that is accomplished.
You could very well be right on the "gelled fuel" for the OP.

 

[bigdeano]

If I had the OP's problem of not starting, I'd point my 110,000 btu torpedo heater under the front of the tractor for an hour. The tractor would think it's starting on an 80 deg day.

Another way would be to tow it with something gasoline powered, which would be more likely to start at that temperature