|
Windchill only affects animals, it makes it feel chillier than it is (hence the name), it doesn't reduce the actual temperature, only the perceived temperature.
|
Quote (Wikipedia)
"The concept of wind chill is of particular significance in very cold climates such as the Arctic and Antarctic, at high altitude, at high speeds, or in very high winds. It is of great importance to the survival of humans and animals, and can even affect machinery and heating systems."
|
You'd need air much colder than +5 and a strong wind blowing over a cold vehicle to achieve significant windchill. We used to get that kind of weather in N Norway from time to time. So cold that the lube oil in the Wessex Vs was drained and kept in heated tanks, as was the fuel. We had only a few minutes to get them started before it cooled.
I don't know what the OP was suffering from, but I doubt it was diesel waxing.
|
|
There is certainly some odd derv in France-I filled my car at a small Elf garage and noticed that I could fill it straight to the top-no foaming or bubbling whatsoever.Querying it later was told that Elf must have put too much anti-foam agent in that consignment.
|
|
|
|
Some woolly thinking here.
Wind chill is a process where heat is removed from an object by conduction of heat from the warmer body to the cooler air passing over it.
It will affect anything that is warmer than the ambient air temperature. Its effects grow with increase in temperature differential and with increasing wind speed. It cannot bring the temperature of the warmer body below ambient temperature. It also doesn't affect anything that does not have a temperature differential to start with - a car parked for longer than two or three hours for example.
|
let me get all this right then..........
spose is driving his transit which is a commercial vehicle where the tank is large and plastic and low and also possibly open to the elements if its pickup style body,the pipes are not protected by anything the filter is well down on older transits and the man drove 10 miles before he had a problem?
how can anyone say after all that that windchill on the system can not have an effect?
maybe a walk in a wind at 50mph may change some people minds, as that is what spose was doing in reverse :-o
|
It could and would have had an effect. It would have been dragging the fuel pipes and their contents down to the ambient temperature (5 degrees according to the OP).
For you and I, operating at 37 degrees, 5 degrees would be a significant problem. Diesel wouldn't be affected.
|
|
|
|
As with fast flowing highland streams resisting freezing due to flow, fuel flow should reduce waxing when on the move, if the Transit was doing 25mpg at 50mph then it would use two gals, say 10ltrs an hour so 166ml or so per min would flow through the system, not an insignificant amount.
|
>>Some woolly thinking here.
Wind chill is a process where heat is removed from an object by conduction of heat from the warmer body to the cooler air passing over it.
It will affect anything that is warmer than the ambient air temperature. Its effects grow with increase in temperature differential and with increasing wind speed. It cannot bring the temperature of the warmer body below ambient temperature. It also doesn't affect anything that does not have a temperature differential to start with - a car parked for longer than two or three hours for example.
>>
Windchill can reduce a temp lower than ambient when moisture is involved hence (moist) skin is very prone to the effect, with regard to fuel lines if moisture is in contact with them from spray or condensation, i.e moisture coming out of the air as temp drops. I have cribbed this from Wilkepedia by way of an explantion and modified it to make it relevant to the subject:
The wind chill temperature is lower than the air temperature because any windchill increases the rate at which moisture evaporates from a wet object, the phase change of water from liquid to vapor requires the molecules to reach a higher energy state, the energy is acquired by absorbing heat from the surface of the body upon which the moisture is sitting by conduction.
|
|
A valid point, and one that I'd neglected. Evaporation will indeed make a difference, and could be relevant. I'd be surprised if it was much of an issue in this case though, certainly not to take the system down below zero.
|
I really can't understand why everone is arguing the toss about fuel waxing. I'll bet my life that of 100 different reasons for the misfire problem, waxing stands at 101.
I've only ever seen it occur overnight a couple of times (UK) and that was back in the 60's. And that was when cheap die cast truck door handles used to snap because they were so brittle with the cold. More recently, for the last ten years I've worked on a mixed size diesel engine fleet and never come across a waxing problem.
Has any backroomer recently experienced (10yrs) an absolutely indisputable fuel waxing problem ?
|
I agree None...The only time I have seen it was it happen was in the winter of 1962. I was on my way to London early morning in a HIV. Set off from Belper in Derbyshire and the sides of the road were littered with other HGVs. I got as far as Melbourne Derby and I too came to a halt at the side of the road.
Had too wait a hour or two whilst things came to life back at the ranch. Up till then I had never heard of diesel waxing.
The mechanic turned up later and explained what it was and he himself had only just heard of it.
He bought 4 gallons of paraffin with him which he put in the tank. With some kind of heater he got fuel flowing through the filter which was exposed on the side of the engine.
He managed to get the engine started and followed me as far as Hinckley heading for Crick where the M1 then began.
All along the side of the road were HGVs broken down and by now word must have got out as to what the problem was. They had fires lit underneath fuel tanks and it was like a re-enactment of the retreat from Stalingrad.
By the time I got home in a couple of days the papers were full of this happening and I remember the fuel companies saying it wouldnt happen again in future years as they would introduce winter diesel.
To this day I have never personally known of it happening again although I have read discussion on this site as if it were still a regular occurrence.
The only winter to even compare with this one was 1947 which I remember vividly. But being only a boy at this time I would have known nothing about diesel waxing so I wouldnt know if there had been a problem then. Apart from the fact my best mate whose father and elder brothers ran a haulage company and he used to talk of nothing but lorries so feel sure it would have been his main topic for the next month.
Perhaps with red diesel they don't use an additive in winter and it could occur on farms but even that seems a long shot.
So perhaps someone who has experienced this in modern times would explain where and when this occurred.
|
Just a couple of points:
1. Continental winters can and do drop to below -20C from late November, so diesel additives take account of this. I started my Xantia at -15-20 in the mornings without a problem.
2. French diesel includes biodiesel, which RAISES the freezing point compared to staright disel.
Farmers' Weekly has just published some info on tractors, biodiesel etc which I'm sure the BR will find interesting:
tinyurl.com/y68qzl
URL=www.fwi.co.uk/Articles/2006/11/01/99067/
Biodiesel+as+a+tractor+fuel.html
Did you know Herr Diesel ran his first motors on groundnut oil ??
|
|
Actually they were able to run on a variety of fuels including coal dust, but then Ackroyd-Stuart had already proven the concept, and with Hornsby, had produced many commercial engines based on the hot-bulb CI priciple, with the first fuel injection system. A little reference:en.wikipedia.org/wiki/Herbert_Akroyd_Stuart
|
|
1980 in the commercial vehicle park durham city it was getting to the state of boredom calling out recovery companies to light a rag under the tanks
|
Thanks to everyone for your contributions, but my follow-up question must be, if I was not suffering from the onset of waxing, what was the problem?
I have had the vehicle (2.5DI Transit) for 6 years and done 70,500 miles, it has never behaved in this way before. To reiterate, the symptoms were, lumpy runing, loss of power and heavy low frquency vibration (felt mostly through the gear lever). After a stop for lunch of about an hour and a top-up with local fuel it ran OK. It continues to run OK up to today and has covered another 1000 miles.
Remember the original fuel was purchesed in the south of France (from an Intermarche) where it had been 25+ for weeks and the probem occured in Belgium after overnight frost.
Any ideas?
|
Spospe, You moved the goalposts :) now you`re mentioning *frost* rather than 5C...
I still cant see it waxing as the much colder high French alps would also be within reach of your full tank of fuel
and difficult to see how the French would not legislate for this in their fuel specs.
Also a waxed filter *stays* waxed even if the temperature then rises.
Have you water in the filter, to the level that it can *wick* into the element?
An iced, fuel restricted filter IMHO, may just give the symptoms you describe, if its been frozen overnight.
|
>>>Has any backroomer recently experienced (10yrs) an absolutely indisputable fuel waxing problem ?
They put additive in red diesel from october 1st. The trouble is that sometimes we have some summer diesel left. I have not had any diesel waxing recently because the weather has been warmer and I put an additive in if the weather gets cold. My mechanic stocks up with fuel filters in the winter for his customers.
I have seen diesel waxing many times years ago, the filters get full of red wax and have to be changed. We usually use a space heater to warm the tractor up.
I remember Anika Rice advertising Esso diesel which was supposed to be OK to -20C. I had trouble with Esso freezing up and comlained, they told me it was the wind chill, I said that Anika said nothing about that!
Cars now have plastic tanks and the engine is enclosed so there is not much waxing, but if it got very cold I think that quite a few diesel cars would be in trouble. Then all the anti diesel people on this forum would have a field day.
|
|
|
|
Wind chill has no effect in laminar air flows (ie, smooth air around or under a car).
What about lighting a small fire under the fuel tank?
|
>>>What about lighting a small fire under the fuel tank?
I wonder what the insurance company would say when the car is a charred wreck?
|
Oilrag, I did not intentionally 'move the goalposts', so sorry if that seemed to be the case. On the day in question, the air temperature was about 5 degrees when I set off, but that does not exclude a ground frost, with white, ice covered grass.
If the symptoms that I experienced were not due to waxing, then what did cause the problem? I have never had this kind of problem before, and as I have said before, after an hour's stop and a top-up (about 75% more fuel), the engine ran normally.
|
does the transit have apencil filter on the end of the fuel pipe in the tank?
if so then quite likley that it was getting blocked and adding fresh fuel shifted the dirt off it.
had this happen to a leyland tractor in years gone by. jag.
|
|
|
Spospe, Sorry, I did not intent to imply that you "moved the goalposts" on purpose, just that more detail ( *Frost* added to your earlier 5C) potentially expanded the range of possibilities :)
Any water in your fuel filter?
To be honest though, I think it would need a penetrating frost to freeze water in the fuel filter and maintain it for a while with a running engine.
Maybe it was not fuel related and the the hours stop itself allowed heating of another engine related component?
Good luck anyway :)
|
Just a further thought.. I wonder if ( through no fault of your own) that you got a bad tank of fuel, such as a messed up
mix of biodiesel from the garage concerned.
Out of technical interest, if it were my vehicle I think I would take off the fuel filter, check for water, then cut it open with a hacksaw and examine it for wax/dirt on the element.
Then you would have the definative answer as to whether you had fuel waxing, as if so, it will still be in the filter.
Time (IMHO) for a new fuel filter anyway given the fuel concerns.
|
The Transit does have a water-in-fuel indicator, which in my case at least is know to work correctly and on this occasion it did not show any water being present.
I do not know if there is an additional filter in the fuel tank, but the main filter (mounted on the engine block) was changed (by me) about 12-13 thousand miles ago.
It is possible that I could have got a 'dodgy' batch of fuel, but it is strange that the problem only showed up after an overnight stop with its low temperatures.
I fear that we will never get a definitive answer now: thanks to all of you for your suggestions and help.
|
can you not go back and do the whole thing again ;-)
spose not ;-(
|
|
|
|
Wind chill has no effect in laminar air flows (ie, smooth air around or under a car).
Laminar air flows in this context mean that the air flowing close to the surface is moving more slowly than the air further away, i.e. more slowly than the vehicle speed through the air however if moisture is present then windchill is still a factor albeit probably an insignificant one.
|
|
|
|
|
|
|
