how long for the engine to get hot? E320CDi

[Brian WH]

Last but not least, the blanking also restricts the icy cold air passing through the rad and cooling the block, I can tell you that putting your hand out of the window at 30mph at -50c is colder than what you might think.
On all of these things, every little helps, and it is a matter of being rational in what you do.

Life is strange, I will hold the live wire of the mains in my hand with no problems, others say that it will kill me.

1. I cannot remember the last time we had -50c in this country?? Can you??

2. Fine till you shake someones hand.

3. I will trade Engineering qualifications with you anytime Malcom.

 

[television]

1. I cannot remember the last time we had -50c in this country?? Can you??

2. Fine till you shake someones hand.

3. I will trade Engineering qualifications with you anytime Malcom.

This post gets more interesting by the minute.

Doing a web search I see that this question has been asked before, twice answers were posted, one by a well known member here who said the same as me, but he was not taken to task over his post, if one reads all of the answers on this thread its 50 - 50 with the views yet you only pick on my post.
So I looked in the dictionary to see the meaning of the word FORUM and it said " an open discussion group" but is it here.

I posted what I did to over come the problem, and it worked, just as many other people have done. One can take any statement and put it out of text using bits that favour you. Take the -50c bit. In countries where it goes down that low by night, the day temp in the sun can be the same as here, around zero, but that is still uncomfortable in a car that does not get hot.

I do not have to justify myself to you, but I have gone through the stages of blanking off water jacket pipes to get even temperatures throughout the head on rebuilds, and as deputy technical secretary I did manage to give lectures and teach ins once a month for 2 years with the RR Enthusiast Club, this included radiator rebuilding to engines and bodies. they were in the flesh and no hiding behind a keyboard, my marriage breaking up over it was the only thing that stopped it.

Re trading engineering qualifications, its not what you know, its how you use it, since you push the issue rather than post any substantial reason for not doing what did. In defence I do have a nice silver cup given to me by the Secretary of State worded " for his dedicated service in applying his ingenuity and outstanding technical skill"
As a Mod you will always have the last word and edge over me, thats life, I only ever do my best even in spite of some back chat going around, but I do get my fair share of thank you's

Re holding a live wire and shaking hands, providing the other person has rubber shoes on, no problem

 

[fredfloggle]

Last but not least, the blanking also restricts the icy cold air passing through the rad and cooling the block, I can tell you that putting your hand out of the window at 30mph at -50c is colder than what you might think.
On all of these things, every little helps, and it is a matter of being rational in what you do.

Life is strange, I will hold the live wire of the mains in my hand with no problems, others say that it will kill me.

And it will if there is a path to earth through your heart - about 50mA will be enough to start fibrillation - many of us regularly work "live" - the knack is not worrying about live conductors , worry about the earth path.

 

[fredfloggle]

Modern waxstat thermostats open in seconds put one in a pan of water and boil it if you don't believe me. Also the statement about blanking the bottom of the rad not speeding up the warm up is nonsense because the cold water at the bottom of the rad has nothing between it and the engine coolant so to block the icy blast from the bottom of the rad must speed the warm up. All the thermostat does is " partially" restrict the flow, thermodynamically the hot water must rise, but some of the heat is allowed to by-pass the stat to supply the cars heating and de-misting set up and obviously the more agressively the heater is used the slower the engine will warm. Rocket science it ain't

Why not try warming it up slowly , you will find it opens up slowly - sure if you put the oxy-acetylene on it it will open fast -
"Thermodynamically" - try taking off the fan belt during the warm up and tell me how quick you get localized boiling - the water pump still works even when the stat is shut - there is almost certainly an internal bypass to allow the pump to move water around the block without causing local hotspots , only when the block warms does the stat start to open - it's a gradual process , it doesn't just go wallop (unless you are really caning the car ) during this process water starts entering the radiator and cold water from the rad returns to the block - very doubtful (unless the sender was located on the return pipework to the block) that you would ever see the gauge react. Remember as soon as the thermostat starts being affected by colder water then it will close - there will be a little process hysteresis due to the reaction time of the stat .

Remember the "efficiency " of the radiator is not only effected by the ambient temperature - the rate of flow of coolant, the difference in temperature between the coolant and the ambient , the flow of air through the radiator .

As a process engineers we can improve any cooling system by using variable water flow and measuring water on and off temperatures for a feed forward control loop - actually the dynamics are a good deal more complicated than they look . An ideal system would have a closed circuit and a water to water heat exchanger with cascaded loops but it is important to remember that this won't help warm up times unless the engine is transfering energy into the cooling system, and of course the block and oil also has to be warmed up at the same time.

There is also a good deal of difference between our temperate climate and that in say Russia or Sweden , very different rules apply in these cases.

 

[fredfloggle]

1. I cannot remember the last time we had -50c in this country?? Can you??

2. Fine till you shake someones hand.

3. I will trade Engineering qualifications with you anytime Malcom.

For the life of me I cannot see how the "live wire" is relevant to the discussion -

Let's look at this scenario - Malcolm is holding onto his live* wire , and all of the forum members are holding hands and wearing rubber shoes , Malcolm holds Brians hand and half the forum members end up playing their harps-

Explain why.

*let's assume "live" means at 220V relative to earth on an AC system

I find it rather benign that two engineers' are crossing swords about a notional situation and the pair of them haven't considered all the implications of what they are debating .
I've heard all this waffle before - the guy who thought a PT100 had a 100 ohms resistance at 100C , and 0 Ohms resistance at freezing (we had just invented the superconductor) - another guy who need explaining that in steam heating systems , if you put a tonne of steam in , guess what? you got a tonne of water out.

The subject of cooling systems is quite interesting - let us discuss it without resorting to "my spanner is bigger than yours"

 

[Ultymate]

For the life of me I cannot see how the "live wire" is relevant to the discussion -

Let's look at this scenario - Malcolm is holding onto his live* wire , and all of the forum members are holding hands and wearing rubber shoes , Malcolm holds Brians hand and half the forum members end up playing their harps-

Explain why.

*let's assume "live" means at 220V relative to earth on an AC system

I find it rather benign that two engineers' are crossing swords about a notional situation and the pair of them haven't considered all the implications of what they are debating .
I've heard all this waffle before - the guy who thought a PT100 had a 100 ohms resistance at 100C , and 0 Ohms resistance at freezing (we had just invented the superconductor) - another guy who need explaining that in steam heating systems , if you put a tonne of steam in , guess what? you got a tonne of water out.

The subject of cooling systems is quite interesting - let us discuss it without resorting to "my spanner is bigger than yours"

So you have the biggest spanner hey, a degree in quantum physics and the wiring diagram for the human heart to boot, bring on fibrillation (had it several time this last year) it beats exchanging posts with you
P.S. Never been near a thermostat with O/A torch in my life honest Guv.

 

[television]

The only reason that I added the "touching a live wire" bit was to put Brian's remarks about my post of blanking part of the rad into the same context as an old wives tale.
All of my points became exaggerated, and my answer was the only one picked up by him twice, even though others had done the same thing, and the question had been posted twice before I was even a member here, and one of the answers given then, was the same as mine, and that was not challenged

 

[fredfloggle]

The only reason that I added the "touching a live wire" bit was to put Brian's remarks about my post of blanking part of the rad into the same context as an old wives tale.
All of my points became exaggerated, and my answer was the only one picked up by him twice, even though others had done the same thing, and the question had been posted twice before I was even a member here, and one of the answers given then, was the same as mine, and that was not challenged

I'm actually interested in it as a proper engineering problem (which is what it is) - let's keep it that way, take no notice of silly comments.

 

[fredfloggle]

So you have the biggest spanner hey, a degree in quantum physics and the wiring diagram for the human heart to boot, bring on fibrillation (had it several time this last year) it beats exchanging posts with you
P.S. Never been near a thermostat with O/A torch in my life honest Guv.

Please attempt to READ what is written - this is an engineering problem and we can create a model - do you know much about MATLAB?

Sometimes we find that devices are actually a bit more complicated than "I dropped it in boiling water and it opened quick" - well you don't say - tell me something I don't already know , as touching the live wire beats exchanging posts with someone who doesn't really understand the subject.

 

[Brian WH]

The only reason that I added the "touching a live wire" bit was to put Brian's remarks about my post of blanking part of the rad into the same context as an old wives tale.
All of my points became exaggerated, and my answer was the only one picked up by him twice, even though others had done the same thing, and the question had been posted twice before I was even a member here, and one of the answers given then, was the same as mine, and that was not challenged

Malcolm your taking life on a forum too seriously again mate.

Mine, like your comments, are sometimes tongue in cheek, thus the emoticons. Nothing personal from my point of view, just responding to a comment made that is all. I would however never query other peoples engineering knowledge, and I suggest you don't either. Although I agree some answers on this forum need to be taken with a pinch of salt.

Now then Fred about this "Model", where shall we build it? perhaps a colder country than ours would be more suitable to get the relevant test data analysed eh?

 

[Ultymate]

Please attempt to READ what is written - this is an engineering problem and we can create a model - do you know much about MATLAB?

Sometimes we find that devices are actually a bit more complicated than "I dropped it in boiling water and it opened quick" - well you don't say - tell me something I don't already know , as touching the live wire beats exchanging posts with someone who doesn't really understand the subject.

You should read what is written I didnt say I'd had fibrillation through touching live wires. I know nothing of matlab. I do know that the use of CAPITALS is shouting. I have spent my working life working on motor vehicles proffesionally. Finally at no time did I advocate dropping a thermostat into boiling water, if you do warm one "slowly" in a pan of water with a thermometor it will open and close relatively quickly at it's marked temperature,if they did'nt there would be little point them being manufactured in 2 degree increments

 

[fredfloggle]

You should read what is written I didnt say I'd had fibrillation through touching live wires. I know nothing of matlab. I do know that the use of CAPITALS is shouting. I have spent my working life working on motor vehicles proffesionally. Finally at no time did I advocate dropping a thermostat into boiling water, if you do warm one "slowly" in a pan of water with a thermometor it will open and close relatively quickly at it's marked temperature,if they did'nt there would be little point them being manufactured in 2 degree increments

And I didn't say you did .

THERMOSTAT MODEL – The thermostat begins to
open when the coolant temperature warms up to a
certain level. The thermostat continues to open more up
to the point that it is mechanically restricted. The engine
coolant flow rate is dependent on the cross sectional
area of the thermostat. This opening area can be
simplified to a linear relationship of temperature from the
thermostat opening coolant temperature to that which
causes the opening of thermostat to be at its maximum.

Seems like it is a linear relationship which is what we would expect from a capsule type - flow might however be modified by using a shaped orifice plate .


http://delphi.com/pdf/techpapers/2000-01-0939.pdf

Take a look at page 5 .

 

[fredfloggle]

Malcolm your taking life on a forum too seriously again mate.

Mine, like your comments, are sometimes tongue in cheek, thus the emoticons. Nothing personal from my point of view, just responding to a comment made that is all. I would however never query other peoples engineering knowledge, and I suggest you don't either. Although I agree some answers on this forum need to be taken with a pinch of salt.

Now then Fred about this "Model", where shall we build it? perhaps a colder country than ours would be more suitable to get the relevant test data analysed eh?

No need to do things like this by trial and error - my term model refered to a set of mathematical relationships. as I suspect you may already know.

The Delphi paper in the post above is worth reading.

 

[mark.t]

my old e300 td is up to temp in 3 miles ...and blowing warm air and not gone 150 yards lovley:bannana:

 

[Brian WH]

No need to do things like this by trial and error - my term model refered to a set of mathematical relationships. as I suspect you may already know.

The Delphi paper in the post above is worth reading.

Interesting enough they did test it practically too, which is good engineering practice, as parameters are always assumed in Models.

Quote

A coolant temperature model of an internal combustion
engine has been formulated to meet the new On-Board
Diagnostics II (OBD II) requirement for coolant
temperature rationality. The model utilizes information
available within the production Engine Control Module
(ECM). The temperature prediction capability has been
tested for various “real-world” driving conditions and
cycles along with regulated drive cycles

 

[fredfloggle]

You can get the model pretty close however variables like airflow through the radiator and coolant velocity in normal driving are very difficult to calculate . Its OK if you take the car straight onto the motorway at constant speed , but of course that rarely happens.

 

[Brian WH]

You can get the model pretty close however variables like airflow through the radiator and coolant velocity in normal driving are very difficult to calculate . Its OK if you take the car straight onto the motorway at constant speed , but of course that rarely happens.

And of course whether you blank part of the radiator off.

 

[glojo]

Surely enough is enough?

Do all engineers like to score points off each other?

John

 

[television]

And of course whether you blank part of the radiator off.

I am going to ask a Mod to remove this post

 

[television]

Surely enough is enough?

Do all engineers like to score points off each other?

John

It depends on if you are a civil engineer