A good example of an engine needing warming up to get the oil thin is try using a jake brake before you’ve done about 10 to 15 miles in a morning , the oils too thick to go through the holes .
Freight Dog:
From what I can understand operating diesel engines at light loads maintains combustion temperatures adequate to support full combustion. The temperature is influence by engine design such as compression ratio and environment like intake temp. A light load does actually aid an increase of combustion temps.Re piston slap and bore scoring. Under load this will generally take place on the thrust side of the bore face. From what I can read if you’ve an engine that has been idling at sub prime combustion temps for a while, perhaps under wet stacking conditions, the oil dilution would have been taking place. Thereafter when a load is placed upon the engine, bore scoring is a risk. A piston will always be “looser” at moderate speeds (otherwise it would sieze at full throttle). The lubricant is required to mitigate this. Sitting under wet stacking conditions prior to load is probably a bad idea from reading the research
I’d guess we’re defining the question to high idle v light load.It seems obvious that normal driving under road conditions won’t allow for ‘light load’.Especially in the case of regularly mixing a cold engine with motorway conditions.It’s also clear that idle doesn’t create any considerable lowering of temperatures more like the opposite.Which is why stopping at idle is more likely to require the fans to replace the lost airflow through the rad rather than the stat closing to maintain engine temp.When if it’s all about load then it would obviously be a case of the latter rather than the former.While it’s obvious that you can’t use load to ‘maintain’ heat in a cold engine anyway.The only possible advantage can be a ‘reduction’ in warm up time although even that is doubtful as the thermostat is more important in doing that in either case.
Which just leaves the questions of applying considerable load to a cold engine can only increase the amount of fuel put into the same cold cylinder while also magnifying any piston slap issues among other arguable issues.The only possible upside being a marginal ‘reduction’ in warm up ‘time’ ?. 
newmercman:
I’ll remember that when I’m buying my next Porsche… if only…Sent from my SM-G930W8 using Tapatalk
You can prob get one for the price of a set of hubcaps for your CAT beast, you’re in the states too. Bet there’s some right bargains there 
.
Carryfast:
.It’s also clear that idle doesn’t create any considerable lowering of temperatures more like the opposite.Which is why stopping at idle is more likely to require the fans to replace the lost airflow through the rad rather than the stat closing to maintain engine temp.When if it’s all about load then it would obviously be a case of the latter rather than the former.While it’s obvious that you can’t use load to ‘maintain’ heat in a cold engine anyway.The only possible advantage can be a ‘reduction’ in warm up time although even that is doubtful as the thermostat is more important in doing that in either case.
I think there’s is some crossing of diesel and petrol taking place. Diesels run at sub optimal combustion temperatures at idle. Extended idling, even after a run can return the engine to sub optimal combustion. Unlike a petrol, the airflow is not restricted at idle via the throttle. The same is also true for turbocharged diesels at high idle. It isn’t solely about load, the risks of glazing and wet stacking are greatly reduced at higher engine speed alone.
Carryfast:
Which just leaves the questions of applying considerable load to a cold engine can only increase the amount of fuel put into the same cold cylinder while also magnifying any piston slap issues among other arguable issues.The only possible upside being a marginal ‘reduction’ in warm up ‘time’ ?.
“Piston slap” is a result of excessive wear of the piston, liner or bore growth.
Piston clearance, is inbuilt and designed.
Piston clearance will always be present whilst operating at less than maximum rated engine regimes, otherwise, the engine would not function throughout a wide range. Piston clearances are protected when lubricant feed is present. Even cold lubricant. However, the excessive wear that can lead to piston slap can be caused by operating the engine under wear conditions, such is wet stacking during idling that destroys the lubricant film.
Carryfast:
Freight Dog:
…I’d guess we’re defining the question to high idle v light load.It seems obvious that normal driving under road conditions won’t allow for ‘light load’.Especially in the case of regularly mixing a cold engine with motorway conditions.
I thought this issue about motorway conditions had already been addressed, when I pointed out that most vehicles being cold-started are several minutes away from the nearest motorway, and most vehicles are not so heavily loaded as to require anything like sustained full throttle at cruising speeds.
It’s also clear that idle doesn’t create any considerable lowering of temperatures more like the opposite.Which is why stopping at idle is more likely to require the fans to replace the lost airflow through the rad rather than the stat closing to maintain engine temp.
That’s confusing two different things. The input of heat into the combustion chamber, versus the performance of the cooling system which relies on forced air. The heat in could fall to a tricklr, but if the heat out drops to nothing without air movement through the radiator, then obviously the fan will start - not because idling makes the engine hotter, but simply because a stationary radiator expels almost no heat at all (not even the trifling amount at idle).
When if it’s all about load then it would obviously be a case of the latter rather than the former.While it’s obvious that you can’t use load to ‘maintain’ heat in a cold engine anyway.
It certainly seems plausible to me that, when the engine block is cold and heat is therefore more quickly conducted away from the combustion chamber, an additional load which causes the amount of heat input to increase, is better able to maintain the temperature of the surface of the chamber against the conduction of that heat deeper into the block (and into the coolant).
Freight Dog:
I think there’s is some crossing of diesel and petrol taking place. Diesels run at sub optimal combustion temperatures at idle. Extended idling, even after a run can return the engine to sub optimal combustion. Unlike a petrol, the airflow is not restricted at idle via the throttle. The same is also true for turbocharged diesels at high idle. It isn’t solely about load, the risks of glazing and wet stacking are greatly reduced at higher engine speed alone.“Piston slap” is a result of excessive wear of the piston, liner or bore growth.
Piston clearance, is inbuilt and designed.
Piston clearance will always be present whilst operating at less than maximum rated engine regimes, otherwise, the engine would not function throughout a wide range. Piston clearances are protected when lubricant feed is present. Even cold lubricant. However, the excessive wear that can lead to piston slap can be caused by operating the engine under wear conditions, such is wet stacking during idling that destroys the lubricant film.
In this case we’re only discussing relative combustion temperatures dependent on the difference between a cold v warm engine ?.In which case the only relative difference in combustion temperature will be that resulting from load ?.
But still minus the same heat soak of the cold engine as the the idling engine in terms of the cold surrounding environment within the cylinder ?.
In which case as I said you’ve got all the same issues of the same cold engine suppressing combustion temperatures regardless.But just with the effect of warming up the same cold engine a bit quicker with the extra heat put ‘into’ the cold cylinder by burning more fuel under load.At the expense of actually pushing in more fuel to create the bigger bang washing more oil off the same cold cylinder walls and any possible piston slap issues resulting from applying load to the larger clearance of the cold piston relative to the bore,while the engine is warming up ?.
On that note I’d doubt if the actual temperature of combustion of the fuel within a cold idling engine is much if any cooler than that within the same cold engine under load.It’s just that you’re burning more fuel creating a ‘bigger’ fire in the cylinder not a ‘hotter’ one thereby marginally warming up the engine a bit quicker.But which is mostly the job of the thermostat.
As for the idea that an idling diesel engine will require the intervention of the thermostat to keep it warm,as opposed to the fan to keep it cool,I’m not convinced.At least unless it’s descending a cold mountain pass which applies to petrol engines just the same.
Rjan:
Carryfast:
Freight Dog:
…I’d guess we’re defining the question to high idle v light load.It seems obvious that normal driving under road conditions won’t allow for ‘light load’.Especially in the case of regularly mixing a cold engine with motorway conditions.
I thought this issue about motorway conditions had already been addressed, when I pointed out that most vehicles being cold-started are several minutes away from the nearest motorway, and most vehicles are not so heavily loaded as to require anything like sustained full throttle at cruising speeds.
It’s also clear that idle doesn’t create any considerable lowering of temperatures more like the opposite.Which is why stopping at idle is more likely to require the fans to replace the lost airflow through the rad rather than the stat closing to maintain engine temp.
That’s confusing two different things. The input of heat into the combustion chamber, versus the performance of the cooling system which relies on forced air. The heat in could fall to a tricklr, but if the heat out drops to nothing without air movement through the radiator, then obviously the fan will start - not because idling makes the engine hotter, but simply because a stationary radiator expels almost no heat at all (not even the trifling amount at idle).
When if it’s all about load then it would obviously be a case of the latter rather than the former.While it’s obvious that you can’t use load to ‘maintain’ heat in a cold engine anyway.
It certainly seems plausible to me that, when the engine block is cold and heat is therefore more quickly conducted away from the combustion chamber, an additional load which causes the amount of heat input to increase, is better able to maintain the temperature of the surface of the chamber against the conduction of that heat deeper into the block (and into the coolant).
The typical cold start warm up under load scenario in the case of leaving an MSA means full load from possibly 10 mph up to 56 mph on the entry slip for just one example.
Why would a stationary radiator need to remove any heat at all assuming an idling engine puts less heat into the coolant than it takes to warm up the engine from cold with the stat closed ?.In which case as I said the thermostat would at least need to close in the case of an idling engine rather than the fan being needed to remove the non existent heat.Also by Biking’s logic in that regard I would have froze during the January and February of 1986 when I was relying on just an idling engine and the cab heater to keep warm during nights out in the Midlands.From memory the Volvo F10’s heater being better at idle than the Marathon’s was under load. 
How does load ‘maintain’ the temperature of a cold engine as opposed to possibly just warming it up marginally quicker ?.
Carryfast:
In which case as I said you’ve got all the same issues of the same cold engine suppressing combustion temperatures regardless.But just with the effect of warming up the same cold engine a bit quicker with the extra heat put ‘into’ the cold cylinder by burning more fuel under load.At the expense of actually pushing in more fuel to create the bigger bang washing more oil off the same cold cylinder walls and any possible piston slap issues resulting from applying load to the larger clearance of the cold piston relative to the bore,while the engine is warming up ?.
This is not correct. A diesel engine will operate at a higher temperature at higher engine speeds than at low idle because of the added fuel requirement. Atomisation of fuel improves at higher revs due injection rate and chamber turbulence increasing with higher engine speed. The tendency for fuel particles to secrete and impinge on cylinder surfaces is reduced at higher engine speeds.
Carryfast:
In this case we’re only discussing relative combustion temperatures dependent on the difference between a cold v warm engine ?.In which case the only relative difference in combustion temperature will be that resulting from load ?.
No this isn’t the case. The causal reason for wet stacking, glazing and bore scoring are associated with poor combustion of diesels at idle due to sub optimal combustion temperatures. Diesel combustion is optimal under load. However, even without load, combustion temperatures are higher and more efficient at higher engine speeds than idle, due to increased fuel rate, efficient atomisation and mechanical mixing of the air/fuel mixture.
Carryfast:
The typical cold start warm up under load scenario in the case of leaving an MSA means full load from possibly 10 mph up to 56 mph on the entry slip for just one example.
Honestly, when did you last floor it out of an MSA from a standing start in your parking bay? You’re not starring in a 70s American cop show.
Use a stopwatch from when you turn the key - you’ll rarely be any closer than 60 seconds to the exit, and at 20-30mph you won’t be having to use full throttle to move the vehicle because of the effect of gearing.
By time you’re on the slip and you put your foot down, the engine (even in the extreme case) has had a minute or more of moderate load to warm up. Normally, it will have far more.
Why would a stationary radiator need to remove any heat at all assuming an idling engine puts less heat into the coolant than it takes to warm up the engine from cold with the stat closed ?
Any combustion in a typical engine always causes a net input of heat. But the temperature of the engine is not necessarily even across its whole.
The combustion chamber air has to be at least momentarily above the ignition point of the diesel, and of course the air is more likely to be warm if the combustion chamber surfaces are contributing heat to it. They will contribute more heat (and leach less heat in the latter part of the ignition cycle, once the effect of compression has raised the air temperature above that of the chamber walls) if they are still over-warm from the previous combustion cycle, without conduction having had a chance to cool them - “over-warm” meaning warmer than the general temperature of the block and the coolant.
At idle, so little heat may be getting pumped into the chamber walls, that they may settle at close to the coolant temperature (rather than the much hotter temperature when the engine is under load).
In which case as I said the thermostat would at least need to close in the case of an idling engine rather than the fan being needed to remove the non existent heat.Also by Biking’s logic in that regard I would have froze during the January and February of 1986 when I was relying on just an idling engine and the cab heater to keep warm during nights out in the Midlands.From memory the Volvo F10’s heater being better at idle than the Marathon’s was under load.
As I say, I think you’ve misunderstood his argument.
How does load ‘maintain’ the temperature of a cold engine as opposed to possibly just warming it up marginally quicker ?.
Because we’re not talking about maintaining the engine temperature as a whole - in the case of a cold engine, we don’t want that to be merely maintained, we want it to increase.
We’re talking about the temperature of the exposed areas of the combustion chamber, and as much as possible maintaining them above the temperature of the (cold) engine as a whole in order to support more efficient combustion.
That temperature gradient will be at its most extreme if you thrash a stone-cold engine, because the combustion chamber will heat far more rapidly, and stay far hotter between each ignition, than the overall temperature of the engine would suggest. Whereas if you are idling the engine with zero load, you are putting less heat into the chamber to begin with, and at low revs you are also giving conduction more time between each ignition to leach the heat away from the chamber into the (initially stone-cold) cooling system coolant.
Freight Dog:
Carryfast:
In this case we’re only discussing relative combustion temperatures dependent on the difference between a cold v warm engine ?.In which case the only relative difference in combustion temperature will be that resulting from load ?.
No this isn’t the case. The causal reason for wet stacking, glazing and bore scoring are associated with poor combustion of diesels at idle due to sub optimal combustion temperatures. Diesel combustion is optimal under load. However, even without load, combustion temperatures are higher and more efficient at higher engine speeds than idle, due to increased fuel rate, efficient atomisation and mechanical mixing of the air/fuel mixture.
How is that a case for warming it up under load as opposed to high idle ?.
While diesel combustion isn’t optimal at all in the case of a cold engine.Which is why starting up a cold diesel creates lots of smoke resulting for the unburnt fuel.Adding revs just creates even more smoke while adding revs and load will obviously push even more fuel into the same cold cylinders creating even more smoke.In all cases it’s the cold cylinder temperatures which are causing the poor combustion nothing to do with engine speed.While throwing in lots more fuel in the form of high engine speed,let alone combined with load,will just add to the problem,until the cylinders have warmed up.IE high idle to minimise fuel input while minimising warm up time is the best option.Bearing in mind that with all the modern PC emissions crap no one sees the reality of what happens when you chuck a load of fuel into a cold engine.On that note maybe you can explain why the least exhaust smoke here coincides with idle and the worst with load. 
Rjan:
Carryfast:
The typical cold start warm up under load scenario in the case of leaving an MSA means full load from possibly 10 mph up to 56 mph on the entry slip for just one example.Honestly, when did you last floor it out of an MSA from a standing start in your parking bay? You’re not starring in a 70s American cop show.
Use a stopwatch from when you turn the key - you’ll rarely be any closer than 60 seconds to the exit, and at 20-30mph you won’t be having to use full throttle to move the vehicle because of the effect of gearing.
By time you’re on the slip and you put your foot down, the engine (even in the extreme case) has had a minute or more of moderate load to warm up. Normally, it will have far more.
Why would a stationary radiator need to remove any heat at all assuming an idling engine puts less heat into the coolant than it takes to warm up the engine from cold with the stat closed ?
Any combustion in a typical engine always causes a net input of heat. But the temperature of the engine is not necessarily even across its whole.
The combustion chamber air has to be at least momentarily above the ignition point of the diesel, and of course the air is more likely to be warm if the combustion chamber surfaces are contributing heat to it. They will contribute more heat (and leach less heat in the latter part of the ignition cycle, once the effect of compression has raised the air temperature above that of the chamber walls) if they are still over-warm from the previous combustion cycle, without conduction having had a chance to cool them - “over-warm” meaning warmer than the general temperature of the block and the coolant.
At idle, so little heat may be getting pumped into the chamber walls, that they may settle at close to the coolant temperature (rather than the much hotter temperature when the engine is under load).
In which case as I said the thermostat would at least need to close in the case of an idling engine rather than the fan being needed to remove the non existent heat.Also by Biking’s logic in that regard I would have froze during the January and February of 1986 when I was relying on just an idling engine and the cab heater to keep warm during nights out in the Midlands.From memory the Volvo F10’s heater being better at idle than the Marathon’s was under load.
As I say, I think you’ve misunderstood his argument.
If you think an idling engine creates no combustion heat try putting your hand on the exhaust manifold from cold and see how long it’ll be before you have to remove it.I’m sure that’ll also be a lot more than 90 degrees C within around 1 minute or two.
No Biking definitely said the heater would take more heat out of the coolant than an idling engine would put in.
You do know that friction between the liner and piston accounts for around 20% of the losses within the engine which is of course turned into … heat.Which is still considerable even at idle engine speeds.
Which explains why the temperature of the idling engine in my example remained sufficient to keep the cab more or less just as warm while it was idling as when it did when running on the road.Which is probably how we managed to do without night heaters in many cases during those cold 1980’s winters.
You won’t generally be approaching a motorway services entry slip at much more than 10 mph from which you’ll need to accelerate up to possibly 56 mph in the length of the slip road and an engine won’t get anywhere near operating temperature in the time it takes between starting it up and driving out of the truck park.
Suggest you actually time how long it actually takes a truck diesel engine under normal operating conditions to reach around operating temperature from cold v fast idling it ( not a massive difference ).Let alone how much respective unburnt fuel ( smoke ) it will create,idle v load,while it’s doing it.If only you had an old school exhaust without all the emissions crap blocking it to see it all.
Carryfast:
Rjan:
…If you think an idling engine creates no combustion heat try putting your hand on the exhaust manifold from cold and see how long it’ll be before you have to remove it.I’m sure that’ll also be a lot more than 90 degrees C within around 1 minute or two.
Are you wilfully misrepresenting me? 
I said precisely as you say, that all combustion results in heat input into the engine.
No Biking definitely said the heater would take more heat out of the coolant than an idling engine would put in.
You mean the cabin heater? Possibly it may if the fan is on full whack and the outside air fairly cold. My car certainly behaves this way at the highest fan setting (but not at lower settings).
Obviously, combustion is always exothermic and not endothermic, and there must logically be a limit to the amount of heat that the cooling system can extract, but the way I understand his point about “heat loss”, what he means is that desirable temperature gradients will dissipate (or fail to accumulate) at idle, and that the combustion chamber will operate indefinitely below its ideal operating temperature (instead it will operate at something close to the coolant temperature, the maximum of which is regulated by the thermostat, radiator and fan).
You do know that friction between the liner and piston accounts for around 20% of the losses within the engine which is of course turned into … heat.Which is still considerable even at idle engine speeds.
Which explains why the temperature of the idling engine in my example remained sufficient to keep the cab more or less just as warm while it was idling as when it did when running on the road.Which is probably how we managed to do without night heaters in many cases during those cold 1980’s winters.
As I say, you seem to be misunderstanding the principle being illustrated.
You won’t generally be approaching a motorway services entry slip at much more than 10 mph from which you’ll need to accelerate up to possibly 56 mph in the length of the slip road and an engine won’t get anywhere near operating temperature in the time it takes between starting it up and driving out of the truck park.
Suggest you actually time how long it actually takes a truck diesel engine under normal operating conditions to reach around operating temperature from cold v fast idling it ( not a massive difference ).Let alone how much respective unburnt fuel ( smoke ) it will create,idle v load,while it’s doing it.If only you had an old school exhaust without all the emissions crap blocking it to see it all.
I never meant it will reach operating temperature in 60 seconds. I said it’s had a chance to warm up - meaning it’s overall temperature is higher than stone cold, and the combustion chamber in particular will be getting perfectly toasty after 60 seconds of use.
Returning to my point, engines driven by drivers in an unhurried and competent way, almost always have a chance to warm up before experiencing any sustained full load, and that’s why even if one accepts that warming the engine up is good for the engine, well the truth is most engines get warmed up just by doing normal work, and don’t need to be specifically warmed before starting useful work.
Carryfast:
How is that a case for warming it up under load as opposed to high idle ?.
I don’t know. I’m not making that case. Who is? Are you?
I am discussing some of the accepted risk factors typically associated with basic idling of a Diesel engine. I don’t know what your interpretation of high idle is. I am sure it means increasing engine speed, which improves combustion.
Carryfast:
.Adding revs just creates even more smoke while adding revs and load will obviously push even more fuel into the same cold cylinders creating even more smoke.In all cases it’s the cold cylinder temperatures which are causing the poor combustion nothing to do with engine speed…
Atomisation of fuel at idle speeds is typically poorer in Diesel engines.
A naturally aspirated diesel engine ingests a quantity of air that is independent of the amount of fuel being injected. A diesel engine will exhibit wet stacking symptoms if the intake air is cold enough and if the fuel required for power is insufficient to maintain an appropriate combustion chamber temperature.
Away from idle, far from being just a smoke generator, combustion is improved. The combination of more finely dispersed fuel and faster injection will lead to most of the fuel being consumed during the period of combustion since injection rate and chamber turbulence generally increase with engine speed. The risk factors associated with idling are reduced in this envelope, whilst the engine functions to warm. Diesel engines ideally would function under optimum load. Diesel engines attain fuel/air ratio close to stoichiometric ratio at optimum load and then becomes richer again beyond.
In the absence of being able to achieve optimum load it seems various strategies have been explored to mitigate the associated of basic idling, from adding back pressure into the exhaust flow via automatic engine brake through to recommendations to avoid operating at basic idle.
The common strategies seem to be higher revs programmed into the ecu to take the engine away from idle (as in nmm’s CAT) or handbook recommendations to drive away with light load.
Juddian:
Moose:
Juddian:
newmercman:
There are two things I never do, one is buy a toothpaste recommended by dentists and the other is listen to manufacturer’s recommendations on engine life, both for the same reason.Juddian, quite agree, I’ve a Ford ranger 3.2 which has 20000 mile service intervals, the bloody oil filter is the size of a thimble, absolute crap, I change at 10000, I don’t give a toss what the dealership says!
As for warming an engine I always let them run a bit before driving off and always will, I also let them cool for a couple of mins before switching off, can’t be doing with all these experts that say no need in a modern engine, many of which have never even seen inside a modern engine! The things are built as cheap as possible to last just long enough!Sensible chap, same here, half the suggested mileage which works out twice a year, and i too warm up and cool my own vehicles as well as the lorry.
Bought in bulk packs when on offer oil is cheap, a bloody sight cheaper than turbos/engines.On another forum one of the lads reckoned the new Transit has 36000 mile service intervals, somehow i don’t think the sump plug threads are going to wear out before that goes pop.
I quite fancied the 3.2 Ranger, would you recommend it?
New Transit (2ltr with adblue) is indeed 36000ml service also it’s 0 30 oil
Sent from my iPhone using Tapatalk
Freight Dog:
Carryfast:
How is that a case for warming it up under load as opposed to high idle ?.I don’t know. I’m not making that case. Who is? Are you?
I am discussing some of the accepted risk factors typically associated with basic idling of a Diesel engine. I don’t know what your interpretation of high idle is. I am sure it means increasing engine speed, which improves combustion.
Carryfast:
.Adding revs just creates even more smoke while adding revs and load will obviously push even more fuel into the same cold cylinders creating even more smoke.In all cases it’s the cold cylinder temperatures which are causing the poor combustion nothing to do with engine speed…Atomisation of fuel at idle speeds is typically poorer in Diesel engines.
A naturally aspirated diesel engine ingests a quantity of air that is independent of the amount of fuel being injected. A diesel engine will exhibit wet stacking symptoms if the intake air is cold enough and if the fuel required for power is insufficient to maintain an appropriate combustion chamber temperature.Away from idle, far from being just a smoke generator, combustion is improved. The combination of more finely dispersed fuel and faster injection will lead to most of the fuel being consumed during the period of combustion since injection rate and chamber turbulence generally increase with engine speed. The risk factors associated with idling are reduced in this envelope, whilst the engine functions to warm. Diesel engines ideally would function under optimum load. Diesel engines attain fuel/air ratio close to stoichiometric ratio at optimum load and then becomes richer again beyond.
In the absence of being able to achieve optimum load it seems various strategies have been explored to mitigate the associated of basic idling, from adding back pressure into the exhaust flow via automatic engine brake through to recommendations to avoid operating at basic idle.
The common strategies seem to be higher revs programmed into the ecu to take the engine away from idle (as in nmm’s CAT) or handbook recommendations to drive away with light load.
I thought I’d made the case my case being high idle to warm up clear.While you obviously didn’t answer the question as to why the example in the video predictably clearly showed the least unburnt fuel coinciding with idle and the most with load.In which case as I said the best possible compromise to minimise all the issues of fuel wash,piston slap and the gentle thermal expansion of components is to high idle the engine to warm it up not drive the thing off up the road with a bleedin great big filthy smoke cloud,caused by chucking loads of fuel into a cold cylinder,behind it with all the implications of that on fuel wash.Not to mention applying load to a piston that may be rocking around in the bore to whatever degree and components that may be expanding at different rates at different times among other numerous variables etc etc etc.
The difference being that with all the modern day EGR,DPF BS BS CRP blocking up the exhaust you can’t see the difference between a decent driver as opposed to a steering wheel attendant in that regard.While as usual the greens are shooting themselves in the foot on the basis of out of sight out of mind.
Just skimmed over the last few posts, didn’t really take any of it in, I’ve just done a 700mile overnight shift, so I CBA, but the gist of it is that I agree with our resident lunatic, but from his posts we agree for different reasons, I like my engine up to temperature before setting off purely to thin the oil out so it can do it’s job better, all the rest of the apparent reasons are of little interest to me.
My engines sound smoother with a bit of heat and my completely free flowing exhausts on my CAT engined lorry blow out no visible smoke under load, save for a puff of black smoke when I change gear, that’s old school seat of the pants stuff and it makes me happy.
Sent from my SM-G930W8 using Tapatalk
newmercman:
Just skimmed over the last few posts, didn’t really take any of it in, I’ve just done a 700mile overnight shift, so I CBA, but the gist of it is that I agree with our resident lunatic, but from his posts we agree for different reasons, I like my engine up to temperature before setting off purely to thin the oil out so it can do it’s job better, all the rest of the apparent reasons are of little interest to me.My engines sound smoother with a bit of heat and my completely free flowing exhausts on my CAT engined lorry blow out no visible smoke under load, save for a puff of black smoke when I change gear, that’s old school seat of the pants stuff and it makes me happy.
Getting up to a decent oil temp before applying load all fits under the heading of ‘numerous variables’ and the issue of applying load to a cold engine obviously means chucking loads of extra unnecessary fuel into a cold cylinder creating a corresponding load of extra unnecessary smoke and with it fuel wash over the cold bores.
Old school rules.
newmercman:
Just skimmed over the last few posts, didn’t really take any of it in, I’ve just done a 700mile overnight shift, so I CBA, but the gist of it is that I agree with our resident lunatic, but from his posts we agree for different reasons, I like my engine up to temperature before setting off purely to thin the oil out so it can do it’s job better, all the rest of the apparent reasons are of little interest to me.My engines sound smoother with a bit of heat and my completely free flowing exhausts on my CAT engined lorry blow out no visible smoke under load, save for a puff of black smoke when I change gear, that’s old school seat of the pants stuff and it makes me happy.
Sent from my SM-G930W8 using Tapatalk
The resident lunatic’s theory is a confusing hotchpotch of questionable deduction and misuse of terms such as piston slap that does not dovetail with accepted theory. Despite inward conflict and questionable arguments he is now a proponent of something that we all have been stating since the beginning by what appears, happy accident. Instead of defending idling a diesel to warm as per the original post, he has subtlety migtrated to the subjective term “high idle”.
What that means is running an engine at higher revs than idling, which we’ve all since post one stated the research shows is beneficial over idling and indeed appears in many manuals. In essance this is to take the engine out of the risk area associated with idling. Running under light load is an optimum method that does appear appear in some manuals. In light of the findings, it appears manufacturers are increasingly building in automatic engine start sequences that progress the engine schedule away from idle where the risk of glazing, bore scoring and wet stacking are most prominent.
A flick through my prior posts will spot a consitant personal approach. I have time and again advocated following manufacturer guidance above all else. Not least because manufacturers change the software and hardware in response to development and research. Which is why I find the staunch across the board advocates of “idle to warm” so hard to comprehend. Such an attitude shuts out reception to feedback. It is perhaps recognising that old habits die hard that has lead to manufacturers fitting automated engine regimes such as turbo timers and engine start sequencing to protect users from this stubborn trait.
Carryfast:
I thought I’d made the case my case being high idle to warm up clear.:
Absolutely not. In fact the opposite. So strong a proponent of idle to warm you posted a video of a Lancaster running in effort to attempt to discount what I had said and show an engine being warmed up by idling. I pointed out the Lancaster would not be sitting at idle power whilst warming. You didn’t answer.
I have pointed out three key areas. Idling a diesel can risk damage. Increasing engine speed can decrease the risk of wet stacking, bore scoring and glazing. Ideally Diesel engine combustion is improved when under load.
On face value you now appear to agree that idling a diesel to warm it up is undesirable. You seem to now agree on one of the points I raised. That increasing engine speed does have a beneficial effect on a diesel. Yet this was your response to my points:-
Carryfast:
At the expense of actually pushing in more fuel to create the bigger bang washing more oil off the same cold cylinder walls and any possible piston slap issues resulting from applying load to the larger clearance of the cold piston relative to the bore,while the engine is warming up ?
I sense some conflict in whether you believe increasing engine speed is beneficial over idling. Rather than being clear, if anything a rather confused opinion you are projecting?