Cold Start Thickness - Dr. Haas

[demarpaint]

Originally Posted By: 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.


It can't hurt. I installed one over 20 years ago along with an Inverse Oiler on an 88 E-150.

I flip a switch and watch the oil pressure gauge move into the Normal range then start the engine. I can't say how well it works or doesn't work, but I am willing to bet its a big help. How much a help is anyone's guess.

 

[Big Jim]

Originally Posted By: 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


I'm going on memory of when I lived in Montana over 40 years ago. We had "tank heaters" back then that were plumbed in line with the heater core. After they had been on about two hours, the whole engine compartment was noticeably warmer. The bottom of the pan was certainly warmer than outside.

This would be easy for someone to check that live in a cold climate.

 

[_phil_]

Having read this thread, I'm leaning to the the following conclusion:

WRT to oil thickness (viscosity), whether we are talking hot or cold, I suspect that so long as it falls within the quite wide boundaries that allow sufficient flow and film thickness its influence on engine wear - and in particular at start up - is limited.

Engine wear during the warm up phase is less dependent on absolute oil viscosity than it is on incomplete combustion (or an inability to fully vaporize by-products and blow them out the exhaust) and less than optimum mechanical clearances.

 

[Shannow]

There's also the period during warm-up where the additives haven't kicked in yet, but viscosity is dropping.

 

[_phil_]

>>"There's also the period during warm-up where the additives haven't kicked in yet, but viscosity is dropping."

I don't understand the point you make here.

 

[Gary Allan]

He's saying that the boundary layer protection requires heat to replenish itself from the oil. At least at the rate required to eliminate start up wear. Since the focus of the discussion is mainly cylinder/ring wear, it means that the dwell time at volume isn't enough to do the job at the localized "hot" level.

..but that still sorta leaves you with a "composite" view. Is it the oil that's not hot enough to plate out on a hot enough surface ...that is, coming in @ 45C and leaving @ 75C won't do it, or is it that the surface can't be plated out on until it reaches a given temp with the rate of throughput of additives? I imagine that it's a crossover/combo of both or either.

 

[il_signore97]

^I agree Gary.

I'd imagine that even if the oil was very hot, but the metal surfaces were cold, you would get localized cooling of the hot oil and likely less than an optimal amount of plating for proper protection during boundary lubrication.

 

[ravenchris]

You solve the problem...then what do we do with all the immortal ICE's?

 

[Taylor]

So lack of lubrication early on could play a role in ring/wall wear? Would a piston squirter make a difference?

 

[Big Jim]

The main function of a piston squirter's main function is to cool the pistons, not to provide lubrication.

 

[Gary Allan]

Well, that's their primary design function, but I guess it would/could also have co-benefits outside of that.

I researched installing them on my 2.5. Then again, I've researched (or tried to) turbocharging where maximum power output wasn't a goal. No one could speak my language.

"You can get 15psi boost out of that ..easy. You just ..."

"Yes, but I only want 5psi boost and I want the turbo to run out of steam at the same place the engine does when NA"

" Huh?

"

 

[SpitfireS]

0W-10 and boost? ...... >

 

[SpitfireS]

Another thought:
What if it would be possible to create an oil that has the same viscosity no matter what temperature it has?
Or a very small viscosity change, lets say 20 cSt at room temp and 10 cSt at 100C, labelled as a 30 weight.

What would happen with the engine?
Would engine desing have to adapt to this oil?

Would this be The Ideal Engine Oil?

 

[Gary Allan]

Your engine would be as happy as it would (from a parasitic loss standpoint) from about 10-15 minutes into the warm up event ..all the time.

It only requires a fluid with around a 800-995 Viscosity Index.

These fluids may exist today ..but can't be adapted to combustion situations ..and they would probably cost $500-$2000/liter.

This calculator max's out @ 350VI

 

[BuickGN]

Originally Posted By: Gary Allan
Well, that's their primary design function, but I guess it would/could also have co-benefits outside of that.

I researched installing them on my 2.5. Then again, I've researched (or tried to) turbocharging where maximum power output wasn't a goal. No one could speak my language.

"You can get 15psi boost out of that ..easy. You just ..."

"Yes, but I only want 5psi boost and I want the turbo to run out of steam at the same place the engine does when NA"

" Huh?

"


That's because a turbo that runs out of breath that badly on the top end will likely put your exhaust backpressure through the roof.

No need for that anymore, the new stuff spools so well you don't have to worry about lag or low end and you use electronics to control it's characteristics such as tapering off the boost toward the upper end of the powerband.

 

[Gary Allan]

Originally Posted By: SpitfireS
0W-10 and boost? ...... >

I missed this

My idea of boost is to simulate/manipulate the power band that's peaking @ 5000 rpm down to 3000-3500. That is, no "more" power at all.