Italian tune-up and oil temperatures.

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Playing around with my multimeter and thermocouple yesterday (Fri) and today.

Caprice has an L67 3800 V-6 engine, mounted longitudinally, as was the way down here, 4L60E, and turns 1,700 RPM or thereabouts at 100km/hr. Holden specified 20W50 for the engine, and 15W40 for prolonged use in "snowing conditions"...it's snowing, and I've not used 50 grade oils for over a decade, 15W40 is what's in it while I'm doing short OCIs on my varnish removal experiment...probaly 5W40 synthetic, or 10W30 A3/B4 when I'm back to normal OCIs.

My commute is around 10-12 minutes, mostly highway, 100km/h, 9 miles give or take.

Bear in mind, only two days into playing.

Yesterday (Friday) 3C, drove to work, pulled in, and measured 82C bulk oil temps.

Drove home, and to stretch the friendship, and as there was a little traffic to keep 100km/hr as fast as it got, I kept it in "2", which held revs around the 4,000RPM mark. Revs are what heats oil, as the engine is working against the lubricant.

On way home, could pull immediately off the highway just before hitting town...I was surprised that at very light load (albeit revs), I got 125C...bear in mind this was highway, and 3-4C, with a big winged alloy sump out in the breeze, little load.

Two minutes across town, and it was down to 86C.

Had to go out that way again today for kid's sports, snowed last night, little settled.

86C on the T/C when I parked. Couple hours later I drove the highway home, left it in "D" and recorded 105C at the same point I got 125 yesterday. slightly higher speed, much lower revs...thus the title of the thread...125C, at nearly no load, just valve burnoff type behaviour, and 125C

Tooling around town to get groceries, hardware, etc. settled it at 90C.

Will be keeping tabs on it over the next week or two, as I said, just for entertainment purposes, but keep in mind, the oil in bearings is 10-20C higher than the bulk.

Checked the thermocouple in a pot of boiling water, and it registered 97C, so is accurate around that region.
 
It would be interesting to see the results using the same method above with 5w40 or even lower viscosity oil. I'm not holding out on this since i know you are a thick viscosity guy.
 
Originally Posted By: deven
It would be interesting to see the results using the same method above with 5w40 or even lower viscosity oil. I'm not holding out on this since i know you are a thick viscosity guy.


Don't listen to the words that the resident ditto heads put into my mouth...as per my original post...

Originally Posted By: Shannow
I've not used 50 grade oils for over a decade, 15W40 is what's in it while I'm doing short OCIs on my varnish removal experiment...probably 5W40 synthetic, or 10W30 A3/B4 when I'm back to normal OCIs.


My Nissan diesel has run since I bough it on 5W40, and 5W30 C3, and has a 5W30/5W50 blend making a light 5W40.
 
I'm ambidextrous in units generally, and a month on a road trip in the US has left me swapping more often than usual.

As a former turbine engineer, m, mm, um, feet, inches, and thousands of inches just swap around as the conversation flows.

Oh, and I bought a quart of MC 5W20 blend while I was over there...sought it out actually.
 
Interesting. I would not have thought it would make that much difference to the oil temp. I would have throught the oil would adsorb more heat from combustion (high load) and not that much from friction. 4000rpm is a fair thrashing for that motor though.
 
Originally Posted By: supercity
Interesting. I would not have thought it would make that much difference to the oil temp. I would have throught the oil would adsorb more heat from combustion (high load) and not that much from friction. 4000rpm is a fair thrashing for that motor though.





My thoughts as well but then I remember as a kid bending a paperclip back and forth to break it in two. Going slow was no problem but bending quickly (furiously I suppose) it burned my fingers and I dropped it.

I'm still amazed by the temps you saw at higher rpm's as I've never looked into this subject before. With my volvo truck I see oil temps of 245-250°f (116-120°c) while pulling long mountain grades in the desert southwest of the U.S. but at 1100-1300 rpm.

Granted, I have a big oil cooler but still amazed a car running 4k rpm sees higher oil temp than my truck moving 80k pounds up a desert mountain. Very interesting info.
 
We must have different understandings of the term you use in the thread title.
To me, an Italian tune-up involves a few WOT runs to redline through the gears, not continuous operation in a low gear.
No doubt you'd see higher transient oil temperatures, but I don't know how you'd measure them without an installed oil temeratures gauge.
 
That's more oil temperature sensitivity to rpm than I would have guessed based on previously owning a 2008 BMW 135i that had an oil temp. gauge. It would be very interesting to see what happens with a much thinner oil.
 
Those are high temps... what would the viscosity be of a 30 weight oil that's rated around 10cst @ 100 degrees at 125 degrees?
 
Where are you at? No snow up here in Queensland yet! :p
My falcon is the same when it comes to needing and italian tune up. I do 95% highway driving and it does 1,500rpm @ 100kmh and changes gear at 1,900! It started running rough so i took it out of economy so it changes at 2,200rpm now and give it the odd thrashing with some injector cleaner and shes running good now!
How many Ks are on your motor? Do you have any probs when running 20w50? Especially since you live in a cold area.
I want to run 15w50 durablend but im worried its too thick
 
A rise in oil temperature with RPM is to be expected, since hydrodynamic friction from viscous oil directly generates heat. Thats why fuel economy goes up using oils with lower viscosity, and heat goes down. Engines equipped with oil-to-coolant heat exchangers perform much better at keeping engine oil temperatures steady, avoiding the huge swings.

The experiment done here may have the most relevance related to sludge formation. Engines with cool sumps could have a tougher time burning off moisture. GM's Oil Life Monitor OLM algorithms use this to determine oil life.

Originally Posted By: Shannow
Don't listen to the words that the resident ditto heads put into my mouth...as per my original post...


As usual Shamwow results to name calling for anyone that disagrees with him. When will he learn to just stick with reasonable logic instead of petty stuff?
 
Originally Posted By: JAG
That's more oil temperature sensitivity to rpm than I would have guessed based on previously owning a 2008 BMW 135i that had an oil temp. gauge. It would be very interesting to see what happens with a much thinner oil.


See earlier post. BMW 135i has a coolant-oil heat exchanger which controls temperatures nicely.
 
Originally Posted By: fdcg27
..To me, an Italian tune-up involves a few WOT runs to redline through the gears, not continuous operation in a low gear..


Not Italian, but that's how I do 'em!
 
"As a former turbine engineer, m, mm, um, feet, inches, and thousands of inches just swap around as the conversation flows"

That just seems dangerous
smile.gif
Do you use the English Royal units as well and the Uppity-Colonist-Modified(UCM) units?
 
Originally Posted By: stickybuns
Originally Posted By: Shannow
Don't listen to the words that the resident ditto heads put into my mouth...as per my original post...


As usual Shamwow results to name calling for anyone that disagrees with him. When will he learn to just stick with reasonable logic instead of petty stuff?


No, re-read what I said...I was name calling the people who make statements for me, then continue the argument attributing me to saying run 70 in your Prius...that's not "disagreeing with someone"...why do you feel you're one of them ?
 
Originally Posted By: Lex94
"As a former turbine engineer, m, mm, um, feet, inches, and thousands of inches just swap around as the conversation flows"

That just seems dangerous
smile.gif
Do you use the English Royal units as well and the Uppity-Colonist-Modified(UCM) units?


If I'm specifiying the final machining steps on a bearing that needs 0.0012" per inch vertical clearance and 0.002" per inch side clearance, and the 14" shaft is 0.002" undersized from the factory, I prefer to use the microcmeter set that came with the machine.
 
Originally Posted By: fdcg27
We must have different understandings of the term you use in the thread title.


I agree sort-of, but it's one of the possibilities that people here are talking regarding valve deposits on DI engines...high revs for periods to burn them off.
 
Originally Posted By: stickybuns
As usual Shamwow results to name calling for anyone that disagrees with him. When will he learn to just stick with reasonable logic instead of petty stuff?

It's not petty, of course, for others to assume that Shannow, being in Australia, uses nothing lighter than 15w-40 as a winter fill. And, with your join date of less than a month ago, you're obviously much more capable of judging Shannow's predilection to resort to name calling than am I.

But, then again, do sockpuppets have birthdays or anniversaries, or is it sort of a reincarnation thing?
 
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