Motor Oil Brand vs Consumption?

[Marky Dissod]

IFF we were able to assume that the valve stem seals are still good, and that the rings were still good ...
Given those 2 assumptions, the only other explanation for oil consumption between oil changes would be that the motor oil gets hot enough to offgas.

Some motor oils get hot enough to offgas @ 248F, which seems within the realm of possibility.

 

[Marky Dissod]

To finish what I was saying, I have not yet found a reliable source for reliable info about the temperature at which any given motor oil gets hot enough to begin to offgas.
Problem with that, is that without an external air-to-oil cooler, or a fan / fans that will keep the oil well under 248F, this offgassing phenomenon may be why some engines appear to consume oil, despite good rings & good valve seals.

 

[donjetman]

ASTM D5800 - 08 Standard Test Method for Evaporation Loss of Lubricating Oils by the Noack Method.

http://www.pqiamerica.com/Testdescriptions/Noack.html

If one whats to know about "all things oil"? Bobistheoilguy forum

 

[EddieC]

If you find your local ACDelco dealer they may give you a good price on it. I've been buying it from Rock Auto for a few years now, last was $8.15 per quart delivered. Then when I thought my order was lost, I bought a couple cases from Summit Racing for $8.99 a quart delivered.

Plan B in case ACDelco got too hard to get or expensive was Shell Rotella Gas Truck but that appears to be gone now. So next down the list on viscosity was Quaker State. We're going to try it out on the next oil change and see if the motor rattles on start up like M1 used to do.

Giving Rotella Gas Truck a try. It took some effort to track it down but I think I have a couple sources for a while.

I also decided to install a ValvoMax drain plug to atleast keep that area clean and reduce the splash.
Now if someone came up with a solution for the messy oil filter removal.

 

[swathdiver]

Now if someone came up with a solution for the messy oil filter removal.

 

[EddieC]

View attachment 399422

That definitely won't fit between my filter and the closely adjacent face of the oil pan. I couldn't even get an open freezer bag in there today. An offset filter mount might be a good idea.

 

[swathdiver]

That definitely won't fit between my filter and the closely adjacent face of the oil pan. I couldn't even get an open freezer bag in there today. An offset filter mount might be a good idea.

You just bend it into whatever shape you want. The filter sockets make removal quicker but still need 4 or 5 blue shop towels to clean up the mess and hands!

 

[BG1988]

I have to wonder how much of that is being lost through the crankcase vent.

If you have a catch can, you have a method to recover and measure it.


When I get the jeep 100% I'm planning to dig into my tahoe once more, different lifters going in, and I have a corvette/camaro style pcv for the gen 4.
It replaces the valley cover between the cylinder heads.

I think most of the oil in my PCV comes from the lifters bleeding way too much oil due to my double pac springs in the AFR heads that I'm running in my 6.0.

I'm also running 15w40 oil right now to minimize the valvetrain noise and to keep the shit lifters I have pumped up.

I'm surprised that I'm still getting anything in the pcv, it reduced, but it's still there.

vegetable oil gets thicker then molasses

 

[BG1988]

To finish what I was saying, I have not yet found a reliable source for reliable info about the temperature at which any given motor oil gets hot enough to begin to offgas.
Problem with that, is that without an external air-to-oil cooler, or a fan / fans that will keep the oil well under 248F, this offgassing phenomenon may be why some engines appear to consume oil, despite good rings & good valve seals.

but if the oil gets that hot then that means a friction problem

 

[Marky Dissod]

... but if the oil gets that hot, then that means a friction problem.

Firstly, we don't quite know exactly how hot
'that hot'
really is.
Don't know exactly where in the engine is the hottest motor oil, but it's NOT the sump.
So keeping track of motor oil temps in the pan is overly optimistic. By how much?

Secondly, is there a freakin motor oil that brags about the temp when it begins offgassing?
Long ago, I think this was referred to as 'thermal breakdown'.
My guess is no. If I'm wrong, I'll be happy, so long as it's at least 275F - the hotter, the better.