Sustina 0W-20, 6,003 kms, Caterham

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Good post - another positive miles/hours, not time in sump UOA. The Glen was always one of my favorite tracks, but I liked it better before the "inner loop aka bus stop" was put it. Of course for absolute white knuckle road courses, it's tough to beat Mosport - and of course Road Atlanta when it still had the flat out dip before the bridge. The good old days.
 
Originally Posted By: Gasbuggy
Originally Posted By: CATERHAM

As it turned out on a very hot track day at Watkins Glen in July/14, oil temp's actually approached 110C (230F) at the end of some afternoon track sessions



Is this considered hot? My caddy gets close to that in July beach traffic, or after a good blast down the highway.

For a car that's not spec'd for a 20 grade I consider 230F to be about as hot as I would want to run a 2.7cP HTHSV oil, especially considering
I'm a bit below the minimum recommended oil pressure. If I was routinely seeing oil temp's
that high I would thicken the oil up some raising the HTHSV to 2.8 to 2.9cP, approaching that of a light 30 grade. Or better still, keep the lighter 20 grade and install a thermostatically controlled oil cooler
with a target maximum oil temp's of 206-212F.

The spec' oil for your Corvette engined Caddy is
M1 5W-30 which can handle oil temp's of 270F before the electronic safety nannies start to kick in, and to get oil temp's that high usually requires some pretty lengthy track time.

We do have some Corvette owning members that run a 0W-20 in their street only driven cars even through the summer months. One great thing about your cars is that they come factory equipped with oil gauges so you can fine tune your oil viscosity to how you personally use your car if so inclined.
 
I forgot to add that for a vehicle spec'd for a 20 grade, 230F is not necessarily a temperature limit.
For example, the Subie BRZ/Scion FR-S twins can easily generate oil temp's higher than 230F but these cars were engineered from the get go with the 0W-20 grade as the specified lube.
 
Originally Posted By: bigt61
Good post - another positive miles/hours, not time in sump UOA. The Glen was always one of my favorite tracks, but I liked it better before the "inner loop aka bus stop" was put it. Of course for absolute white knuckle road courses, it's tough to beat Mosport - and of course Road Atlanta when it still had the flat out dip before the bridge. The good old days.

Yes the bus stop does detract from The Glen but I am looking forward to going back this year now
that it's been repaved with some special "porous" asphalt.
 
Originally Posted By: Shannow
Do you know where the Manganese resides in your engine ?


Do you use an MMT fuel additive perhaps ?
 
Originally Posted By: Shannow
CATERHAM, considering the usage, that's not a bad UOA...what do you calculate the KV100 of the brew should have been before use versus what it was at end of test Do you know where the Manganese resides in your engine ?

I know and agree that your Oil Pressure tests correlate to an HTHS value, what did you calculate the HTHS at start and finish of the test period ?


Using data from here
http://www.eneos.us/wp-content/uploads/2016/01/ENEOS-SUSTINA-Product-Data-Sheet-2015.pdf

and Widman's calculator, mix should have been 8.72Cst KV100, so it's sheared 9% give or take, would correspond to a loss in HTHS of about 4.5-5% over that run.

So your oil pressure at the end of the run should have been the same as the 0W20 without the 0W50.

Is that what you saw ?
 
Originally Posted By: CATERHAM

Of course having oil gauges allows one to do away with having an excessively high viscosity reserve with no risk once you become comfortable relying upon them.
But the manufacturers need to specify an oil grade will a large viscosity reserve to deal with all the potential unknowns such as fuel dilution, oil shear and unexpectedly high oil temp's that could happen when one is driving blind so to speak.
The last factor, unexpectedly high or abnormally high oil temp's manufacturer's do have more of a handle on now than they once did through the use of electronic safety management controls which has enabled lighter oil grades to be specified.
So given the option, that's why it's best
to run the lightest oil a manufacturer specifies
and if that is heavier than a 0W-20, and you have oil gauges, you will know if can run something lighter with the way you operate your car.


While I agree that your oil pressure/High shear viscometry correlation is sound, again, the OEMs are using their minimum oil pressure recommendations on their RECOMMENDED lubricants as an indicator of when equipment needs mechanical intervention.

It's not the "minimum" oil pressure to target viscosity selection.

The pressure and temperature gauges cannot "see forward" into what's happening in the big end bearings for example. The big end temperatures are MUCH MUCH higher in temperature than the bulk oil temperatures, and only intermittently oiled depending on feed hole locations and main bearing grooving.

I know you've discounted on a number of occasions that the temperature rises across the bearing because of oil shear, rather than the misconception that it's "carrying away" combustion generated heat, but it's there.

Piston cooling squirters (where fitted) are pressure driven, so targetting lower oil pressure is intentionally reducing squirter flow....and even Honda have stated that one of the challenges with low viscosity induced oil pressure is maintaining operation of cam phasing hydraulics.
 
Originally Posted By: Shannow
Originally Posted By: Shannow
CATERHAM, considering the usage, that's not a bad UOA...what do you calculate the KV100 of the brew should have been before use versus what it was at end of test Do you know where the Manganese resides in your engine ?

I know and agree that your Oil Pressure tests correlate to an HTHS value, what did you calculate the HTHS at start and finish of the test period ?


Using data from here
http://www.eneos.us/wp-content/uploads/2016/01/ENEOS-SUSTINA-Product-Data-Sheet-2015.pdf

and Widman's calculator, mix should have been 8.72Cst KV100, so it's sheared 9% give or take, would correspond to a loss in HTHS of about 4.5-5% over that run.

So your oil pressure at the end of the run should have been the same as the 0W20 without the 0W50.

Is that what you saw ?


I guess that the 0W50 component evaporated during this interval, leaving only the titled Sustina 0W20 at the end of the run...interesting posit...
 
Those oil temps are pretty low. How hot is the coolant getting? How many times had you spun out into the dirt on that oci? That may açount for silicon. How fast are you getting at the end of the Mario straight? What engine is in that car?
 
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Normal coolant temp's are about 195F but can rise to 210F on a hot day in close racing.

I've never spun the car or driven under dusty conditions during this OCI. I did spin the car during the previous OCI on the back straight at Mosport after hitting some oil, ending up next to the inside guardrail. The car was covered
in dust and grass but otherwise undamaged other than a scraped rear fender and flat spotted rear tires.

Terminal speed at the end of the back straight before hitting the brakes for corner 8 is about 125 mph driving at 10/10th.
More typically at 8-9/10th 150-120 mph is more typical

The engine is a Vauxhall/Cosworth (C20XE) 2L 16v
four with about 190 HP in it's current state of tune.
 
dailydriver, I thought we had discussed the history of the C20XE engine in my Caterham in the past but maybe not.
Anyway, in the late 80's GM of England (Vauxhall) contracted Cosworth to develop a high output four cylinder 2L engine based on an existing GM block. Vauxhall was to use this engine in a production based rally car.
A couple of Vauxhall models received this engine
and initially the cylinder heads were actually
made by Cosworth but eventually GM took over production of the cylinder head.

The engine remained in production until 1996.
Because of the engine's design it was attractive
to engine tuners and the small production specialty car company, Caterham.
Caterham wanting a powerful 4 cyl engine with relatively easy tuning potential up to 300
normally aspirated HP.
I have one of the actual Cosworth made engines.
 
Standard in the Astra/Vectra/Kadett range with the Cosworth designed and cast heads. Didn't know that Cosworth actually built engines for GM, but learn something new every day.

(Second part of my engineering thesis was to develop a test rig to study in cylinder flows of the SOHC version of this engine, as it was available globally with various displacements, and obviously this new head had heaps of opportunity to be reviewed regarding tumbling flow as opposed to plain old swirl...that, and AE Bishop engineering were working on a rotary valve head, which would have given more options to explore on the test rig.)
 
Originally Posted By: Shannow


I know you've discounted on a number of occasions that the temperature rises across the bearing because of oil shear, rather than the misconception that it's "carrying away" combustion generated heat, but it's there.

Piston cooling squirters (where fitted) are pressure driven, so targetting lower oil pressure is intentionally reducing squirter flow....and even Honda have stated that one of the challenges with low viscosity induced oil pressure is maintaining operation of cam phasing hydraulics.


1. Whatever way the heat is generated, a less viscous oil will flow more excess to the bearings and provide more cooling. So the bearing runs cooler and doesn't need a higher viscosity to provide min film thickness.

2. A less viscous fluid will flow more material through an orifice at a given pressure. So you have to look deeper into each viscosity and each pressure to really know which is the better situation.

3. We've debated the primary input of heat into an oiling system. You think its shear. I think its the piston temp of combustion. The oil squirters were developed to cool the piston. That's what engineers are worried about, right. Doesn't that tell you something?
 
turtlevette,
you can see how much frictional power is generated in motored engine tests in a paper I linked to the other day...happy to continue the conversation in there.

http://www.bobistheoilguy.com/forums/ubb...ils#Post4036102

As to squirters, they are purposely designed to be akin to sharp edged orifices, which are pressure/density related, unlike a hose.

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3857079/Re:_Oil's_affect_on_motorcycle#Post3857079

As to why the engineers put squirters in is simply to keep the piston temperatures controlable, and that's the easiest way of doing it...Mains and Big ends flow heat INTO the water jackets, not out of it.
 
I'd rather have you explain it in your own words. That Chinese paper isn't loading. I dont trust any of their research, if you want to call it that. The other thread is 14 pages of stuff. I get lost in the hand waving. I also know how tenacious you are in attempting to win an argument, linking to some questionable stuff sometimes.
 
While far more anecdotal than scientific, place your hands on an air compressor head when it's being run in for the first time, as in half an hour of free-wheeling with the relief valve open. Then, try doing the same thing if it's been running for half an hour with a relief valve stuck shut, and "note" the difference in temperature. I would suspect the work being done is where the heat originates. Less load, less heat, and there's no gasoline or other petroleum fuel in this case.
 
Originally Posted By: Garak
While far more anecdotal than scientific, place your hands on an air compressor head when it's being run in for the first time, as in half an hour of free-wheeling with the relief valve open. Then, try doing the same thing if it's been running for half an hour with a relief valve stuck shut, and "note" the difference in temperature. I would suspect the work being done is where the heat originates. Less load, less heat, and there's no gasoline or other petroleum fuel in this case.


You're trying to say it takes less HP to pump a thick oil with bypass open than a thinner oil with bypass closed?

Man. That is a terrible, terrible argument. I didn't expect that from you.

Just terrible.
 
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