holmesnmanny

The quote you referenced specifically talks about whether or not you need to fully warm up the car by idling and thereby wasting gas(as a consequence as stated by me later). It simply says you don't need it to be completely warmed up, just to where the gauge moves 1 notch, which basically means it is still about whether you need to warm your car up by idling it or driving it.

The "engine wear" you speak of is/would be a direct result of that action(idling before driving it) in itself that the OP states occurs because of.

holmesnmanny

It's really funny that you say "for one", but there never comes a "two" or a "three" or a "four" for that matter.

Yes, I shoulda used clearance in that instance.

Oh, me? I'm just a cook. Just a lowly lowly cook.

TheShodan

iTrader: (14)

TomCat39

Your selective reading and fictional fabrication skills are extremely proficient.

pogeeboy27

iTrader: (3)

Ok let's make this simple shall we. Do you, holmesnmanny, agree, yes or no, that the statement below from the OP is what we are discussing here?

2LEM1

iTrader: (1)

Dammit. I really need to see this now.

pogeeboy27

iTrader: (3)

*sigh* I really wanted to have this be an intelligent discussion but I guess not. Not even the OP has chimed in since.

TomCat39

I was going to come back to this and isolate your exact highlights to define the discussion and post the theoretical hypothesis to continue the discussion.

I just haven't had a whole lot of time as of late to do so.

I see one of the challenges is we can't exactly measure clearances during various stages of warm up, nor will it be easy to isolate the frictional properties of the oil through various stages of the warm up.

I do feel it's important to clearly define the discussion as wear, how much and when, as most of us comprehended the OP to be regarding.

turbociv910

quicker it heats up= better for enviroment

pogeeboy27

iTrader: (3)

On top of that different combinations of oil, engine materials, clearances, warm up routines (or lack thereof), and weather contribute to the difficulty of finding out whether or not warming up an engine has any effect on engine wear. To date I've simply relied on doing oil analyses on my cars to tell me how my engine is wearing and so far it hasn't done me wrong.

TheShodan

iTrader: (14)

That'd be great, TomCat39. Once you do that, we can call this discussion a wrap, wouldn't you say?

TomCat39

I'm not sure we can ever call this discussion a wrap being we don't have the means for a full blown scientific study.

I mean, you'd need to laser map all parts prior to assembly on all the engines. Assemble all the engines equally and then hand pick combos for each grouping etc. Do your barrage of test runs for all the parameters you want to cover all the bases for. Then rip everything apart and laser map all the parts again.

And even then, the clearance speculations would have to be simulated on cray computers caliber simulations with all the data you have on all the materials in play so you could have the math on the angles and forces at work for each scenario and time segment.

Without all of that.... How can you ever move past the speculation and educated guesses to "wrap up" the discussion?

TheShodan

iTrader: (14)

Very easily.... Considering that no one is going to make the investment to get the data, and then try to explain it all on a discussion board..(Let's be honest here..).. Nah.. It's a wrap as a practical matter.

v4lu3s

Warming Up Your Car in the Cold Just Harms the Engine
https://www.aol.com/article/2016/01/...g-yo/21300954/
this is based on the work of Stephen Ciatti.
https://www.anl.gov/energy-systems/p...stephen-ciatti
He has a PhD in Mechanical Engineering
MS in Mechanical Engineering
BME mechanical engineering
He has been at the Center for Transport research at Argonne National Lab for about 16 years now.
Chair of the ASME internal combustion engine comittee as well
published numerous time per year since 2001 and basically his whole career has been the engineering of internal combustion engines.

If he says fire it up and take an easy drive for the first few minutes and that a cold engine is a bad engine to let idle, I will trust him more than any one on a web forum, 2 engines is anecdotal evidence at the very best. If he arrived at his conclusions after 27+ years of engine experience in the real world and in a lab he probably knows a lot more than most guys about how engines work. Idling is a very slow way to bring an engine up to temp. If i let it do that at idle in my driveway its 15+ minutes, if I drive its less than 5. Same with my diesel truck, at cold start idle it NEVER gets up to temp, and my truck likes ot run at 200-206 coolant, 203-212 oil temp and 184-196 trans temp.

TomCat39

Thank you for sharing. That is very interesting.

One thing I am not a big fan of with the article is the ambiguous statement:

This is as clear as mud. Later it goes on to say the best option on FI cars is to start the car, wait a minute scraping your windows, hop in and go softly.

But the main statement is open for interpretation so closure is impossible without asking further. How much time is an extended period in this application. OP is talking 5 minutes. I usually wait about 2-3 minutes until the idle is beginning to drop. Are either of those extended periods or in the "safe window" for cold idling?

What is clear though is it's bad to attempt idling the car to operating temperature especially in colder weather. And it's bad to get on it when it's cold.

The latter happens a lot in my area. No one does soft throttle on take off at any time, it's almost always 3/4 or more throttle to go from stop with the exception of some Sundays.

Also, is this taking into consideration heated O2 sensors? These get to temp in 5 minutes I've been told and then go to closed loop unless you are 3/4 throttle or more. Does this play a role in the cylinder wash scenario?

It's great info though, that's for sure.

Oh, I think with this article, it's substantial enough to call this thread a wrap....

Idle the car for 1-5 minutes tops while you scrape your windows and lights, then drive softly until the car reaches operating temperature. Case closed.

holmesnmanny

Your continued refusal to admit you're wrong even in the face of such mounting evidence is astonishing but not surprising.

holmesnmanny

I'll keep it simple too.

​​​​​​​

TheShodan

iTrader: (14)

​​​​​​​ basically you two are saying the same thing. Don't idle long, just enough to move oil temp up a notch, then slow driving. Done. Got it. I like it

TomCat39

You really are a combative person, and probably just to be combative, no other reason. SMH

TheShodan

iTrader: (14)

Maybe that's what happens with lowly cooks that stay in the kitchen too long..They get tired, combative, and just angry.

pogeeboy27

iTrader: (3)

Your continued refusal to answer a simple yes or no question is astonishing but not surprising as well.

TomCat39

I found this technical article on aluminum expansion rates.

http://nvlpubs.nist.gov/nistpubs/jre...n3p209_A1b.pdf

It gives good data for amount of expansion per temperature, however it is missing the time/pressure factor.

Going to keep digging and see if I can find any time data. I realize pressure plays a very important role in heat transfer and will affect time.

With this data we can see a rough estimate of how long it takes for the piston to swell. Then we have to find the same data for the chromoly rings as well as the steel sleeves.

Pressures in the cylinder are pretty substantial so I would suspect the heat transfer is pretty efficient and only requiring a few minutes to expand the parts to near maximum.

TomCat39

Now looking at thermal diffusivity on wikipedia, it's indicative that a mean pressure will need to be decided upon to be able to calculate a time frame for the densities of metals involved.

https://en.wikipedia.org/wiki/Thermal_diffusivity

In reality, the computations for this is complex enough to just leave it at the agreed upon, should warm up the car 1-5 minutes and then go softly if your desire is to prolong the life of your engine.

And we should probably define "softly" as 1/2 throttle or less while the engine warms up under load.

Some thermal conductivity figures for materials can be found here:

Thermal Conductivity of common Materials and Gases

Thermal Conductivity of Metals

And then, how does the relationship of the thermal conductivity of gasoline correspond with the thermal conductivity of the aluminum alloy, chromoly and the plain jane steel sleeve?

And is the figure for gasoline when ignited or as an unignited liquid stasis?

Caoboy

Couple all that data with the simple fact that steel and aluminum expand and contract at different rates and you've quite the conundrum on your hands!

pogeeboy27

iTrader: (3)

There must be an SAE paper out there on this subject. These guys test everything car related.