Cold Start Thickness - Dr. Haas

[SpitfireS]

Originally Posted By: Gary Allan
Did I assemble that logic train in a digestible manner?

Yes.
One thing: the term "flooding" has a negative ring to it.
As in, more than it can handle at that time.
Is that why you used that word?
(as far as I know you you do pick your words carefully)
I mean, coolant never gets any hotter than oil and oil being sprayed underneath the pistons heats up pretty quickly.
How fast does oil heat up in a crank journal?
IOW, I don't think coolant can overheat oil, not in temperature and not in time.

So I would like to call it sharing.

Coolant reaches engine parts that oil won't and vice versa.
Share the energy and the engine in total might/should/will see a shorter start-up period.

My engine has a small OEM coolant to oil heat exchanger.
Its located behind the oil filter base plate.
I'm sure the designers did the math.

IMO, increased flow due to thinner cold oil will help to share the energy too.

I can't see any drawbacks in these two things.
Or did I miss something?

 

[Gary Allan]

Quote:
One thing: the term "flooding" has a negative ring to it.


Yes. One should be sensitive in these matters and we should attempt to broadcast happy thoughts whenever possible.

( faint visions of Holden directing Leon to tell him only the "good things" that he remembers about his mother in Bladerunner )

Quote:
As in, more than it can handle at that time.
Is that why you used that word?


Well, more heat than it would normally have access to.

Quote:
(as far as I know you you do pick your words carefully)


Well, that's up for debate. I'd say that I have to choose my words carefully to be understood. Even my best efforts fail ..more times than not. The fault is rarely with the reader.

Quote:
I mean, coolant never gets any hotter than oil and oil being sprayed underneath the pistons heats up pretty quickly.
How fast does oil heat up in a crank journal?


Sure coolant can get hotter than the oil, but for how long and under what conditions? Coolant is regulated and is under forced cooling. Oil temp is not (typically) and is rarely under forced cooling.

Oil will warm from just getting squeezed through a journal and from shearing and whatnot, but the combustion process accounts for most of it. Without load I can't imagine how long it would take to bring cold oil to lukewarm.

Quote:
So I would like to call it sharing.

That works for me. Keep in mind that this is a capitalist nation message board ..so some might take exception to it and want to call it "redistribution of rightfully held thermal assets". I'm just preparing you here.

Quote:
Coolant reaches engine parts that oil won't and vice versa.
Share the energy and the engine in total might/should/will see a shorter start-up period.


Essentially. You're turning an unregulated heat carrying medium into a regulated one. As long as your radiator is of enough capacity, you should be able to contain your oil temp (on the higher output end of things).

Quote:
IMO, increased flow due to thinner cold oil will help to share the energy too.


Well, assuming that you're not in oil pump relief ..the flow should be the flow. I think that thinner oils transfer heat easier than thicker oils ..but when you say that you may be talking about a thick oil that is now thin. That's why you need to say "when".

Quote:
My engine has a small OEM coolant to oil heat exchanger.
Its located behind the oil filter base plate.
I'm sure the designers did the math.


They are very wise. Some assert that they do no more than ponder ways to improve things.

Quote:
I can't see any drawbacks in these two things.
Or did I miss something?


Nope.

(forgive my humor- or at least smile with me)

 

[Shannow]

Without any heat source, just friction, I've seen industrial, ISO32 lubricated bearings with a normal heat ris of 40C

 

[SpitfireS]

Originally Posted By: Gary Allan
( faint visions of Holden directing Leon to tell him only the "good things" that he remembers about his mother in Bladerunner )

"She won't live.. but then again, who does?"

Turned out she didn't have an end date programmed into her ECU.
(this is how I remember that quote, it might actually be slightly different)

So.. what is the consensus after 11 pages?

 

[il_signore97]

Originally Posted By: SpitfireS

So.. what is the consensus after 11 pages?

Well, thanks to everyone's input (especially Gary's), I think a few things have been settled upon here:

Start-up / warm-up wear is really a complex situation most probably arising from thermal gradients within the engine and its fluids.

Thin oil could help, but is certainly not the solution for the start-up wear issue.

Oil to coolant heat exchangers are good - they greatly reduce the time it takes for the oil to warm up. My 3.5L V6 Altima has a coolant to oil heat exchanger, and my coolant temps are typically right up to full in about 3 minutes, and oil temps follow closely behind and reach operating temp in about 8-10 minutes (normally). This is good IMHO. I think more cars should have one of these...

Other than heating your engine and fluids prior to use, I don't think there's a better solution for this issue other than what has been discussed here...

Great discussion guys

 

[Hitzy]

How many people in the southern states are going to get block heaters installed now becasue of this thread

 

[ADFD1]

Originally Posted By: il_signore97
Originally Posted By: SpitfireS

So.. what is the consensus after 11 pages?

Well, thanks to everyone's input (especially Gary's), I think a few things have been settled upon here:

Start-up / warm-up wear is really a complex situation most probably arising from thermal gradients within the engine and its fluids.

Thin oil could help, but is certainly not the solution for the start-up wear issue.

Oil to coolant heat exchangers are good - they greatly reduce the time it takes for the oil to warm up. My 3.5L V6 Altima has a coolant to oil heat exchanger, and my coolant temps are typically right up to full in about 3 minutes, and oil temps follow closely behind and reach operating temp in about 8-10 minutes (normally). This is good IMHO. I think more cars should have one of these...

Other than heating your engine and fluids prior to use, I don't think there's a better solution for this issue other than what has been discussed here...

Great discussion guys

+1 Great discussion very informative!


Good observations. We have one other thing worth considering, in our quest for no engine wear. Heating the block and oil is a big help, however the cylinders are said to be oval when an engine is just started up, and they take time, and heat to get to the perfect round running state. While this is happening start up wear is occurring, and I have a feeling pre-heating will help but not as much as we'd like it to. So pre-heating oil and coolant will help, but just how much?

AD

 

[il_signore97]

^Well, how much is a good question. But in general, adding heat to any part of the engine or fluids will help it get to steady state faster.

I notice much faster warm up times when its brutally cold outside with the block heater plugged in. This can only be a good thing...

 

[Gary Allan]

Quote:
While this is happening start up wear is occurring, and I have a feeling pre-heating will help but not as much as we'd like it to. So pre-heating oil and coolant will help, but just how much?


Let's face it. We're novices with varied levels of experience. Speculation is our main tool given our limited access to the tools required. I'm sure that the definitive studies have been halted or haven't been done since there's little product to bring from the effort. Even if there is some guru somewhere that has done these studies ..he's typically locked up behind a few hundred $$$ wall of intellectual copyright that's well enforced.


..but "while we're here"

I'd say that anything that compresses or shortens the startup wear speculative triangle (visc/part fitment via expansion/additive activation) is a good thing. There's not much more that we can practically manage.

 

[ravenchris]

Lucid.

 

[ADFD1]

Originally Posted By: il_signore97
^Well, how much is a good question. But in general, adding heat to any part of the engine or fluids will help it get to steady state faster.

I notice much faster warm up times when its brutally cold outside with the block heater plugged in. This can only be a good thing...


Anything that cuts the warm up time is a good thing. My question is how long does it take the cyls to go from oval to round, and is it that round state where the engine wear is the least? Commom sense says yes. Does warm oil and coolant help it get "round" faster? Or is it the actual friction generated from running that gets it "round"?

I'm just playing devils advocate, in an attempt to learn more about something that interests me.

AD

 

[[RT] ProjUltraZ]

it's the fire in the hole. the combustion chambers

 

[Gary Allan]

Originally Posted By: [RT
ProjUltraZ]it's the fire in the hole. the combustion chambers


Yes. You can otherwise only simulate the symptoms of a warmed engine. The coolant and oil temps are merely byproducts of much higher combustion temperatures. The heads (aluminum) and pistons would melt without coolant (either oil or water). You can't prewarm an engine into melting.

 

[Big Jim]

Originally Posted By: ADFD1
Originally Posted By: il_signore97
^Well, how much is a good question. But in general, adding heat to any part of the engine or fluids will help it get to steady state faster.

I notice much faster warm up times when its brutally cold outside with the block heater plugged in. This can only be a good thing...


Anything that cuts the warm up time is a good thing. My question is how long does it take the cyls to go from oval to round, and is it that round state where the engine wear is the least? Commom sense says yes. Does warm oil and coolant help it get "round" faster? Or is it the actual friction generated from running that gets it "round"?

I'm just playing devils advocate, in an attempt to learn more about something that interests me.

AD


I think you got this wrong. I think the cylinders stay fairly round, hot or cold. They are well supported in the block and how the cylinder heads are attached.

It is the PISTONS that are not round. When cold they are somewhat oval and become rounder as they warm up. This doesn't create nearly as significant of a wear situation. The only part of the piston that touches the cylinder walls are the skirts, and on most engines, not all the way around. The ring land area doesn't touch the cylinder walls, the rings keep the piston floating away. So what's to wear? Some piston skirt wear from piston slap while it is cold? Nothing significant there.

I suspect the main wear during warm-up is ring and cylinder wall until lubrication of the cylinder walls becomes uniform. And this just isn't significant anymore. We just don't get the cylinder wall wear that we did decades ago. It is not uncommon to tear down an engine today and find the factory cross-hatch hone pattern still evident on the cylinder walls.

 

[ADFD1]

Thanks Big Jim the brain had it right, what happened after the fingers typed it and it hit the page was another story. The point I'm trying to make is pre-heating might help some but those out of shape pistons need time and heat from actual use and movement of the engine to get into the proper shape. All the preheating is doing is thinning the oil a little ahead of time, and that's about it.

AD

 

[Jim Allen]

In the case of piston and bore wear, heating the coolant via a block heater would probably be the best method to hasten the transition into the 4 nanometer wear area.

 

[ADFD1]

Originally Posted By: Jim Allen
In the case of piston and bore wear, heating the coolant via a block heater would probably be the best method to hasten the transition into the 4 nanometer wear area.


Are the Wolverine oil pan heaters any good? They claim you're heating the oil, at the lowest point of the engine, the bottom of the pan, heat rises, and that's their claim to why the oil heater is better than heating the block? Makes some sense, but that's one compaines view, I'm sure the block heater guys have their own reasoning. I'm sure the oil pan block heater combo is the very best............JMO

AD

 

[Big Jim]

Heat radiates outward from the source. Any heating, coolant or oil is helpful. I'm inclined to believe heating the coolant does more good overall and sill somewhat heat the oil as well. Heating the oil will not do as much for heating the overall engine or cooling system.

 

[ADFD1]

You're correct Jim any heating of oil or coolant it helpful. I don't see how heating the coolant via a freeze out plug is going to heat the oil, since the oil is sitting in the pan, at the lowest point of the engine. The heat from the coolant is going to rise up and out from the source. Any heat thrown off of the oil being heated at the bottom of the pan might warm the crank and bearings slightly. IIRC Wolverine had a diagram in their directions or possibly on their website, stating the advantages of heating the oil.

I remember someone possibly a trucker saying a block heater warms the passengers, an oil heater warms the engine. I read that somewhere on this site, I think.

AD

 

[SpitfireS]

How about a pre-oiling system?
Like accusumps.
I know they only "work" during the very first seconds of starting an engine, maybe even shorter.
But how high is the wear rate during that - short - time?
Exponentinally high?

Just throwing it into this discussion.