Thread: Report: Motor Oil In The Supercharger Snout

Ok ignorant quesiton on my part, I am still new to the whole supercharged side of life mind you, what is the weight of the GM Fluid ie 10w30 etc then as compared to what you are putting in there Scotty?

And then another question begs....

Do you have to change that fully Synthetic oil you are using in your snout like you would your motor oil then?

I hope that didnt come out sounding to stupid?

Thanks in adavance

Hmmm. Man Ron, you got me thinking now. It may be completely pointless and un-useful to anyone but me, but now Im wanting to figure out how to solve this.

Originally Posted by GeddyLee

Ok ignorant quesiton on my part, I am still new to the whole supercharged side of life mind you, what is the weight of the GM Fluid ie 10w30 etc then as compared to what you are putting in there Scotty?

And then another question begs....

Do you have to change that fully Synthetic oil you are using in your snout like you would your motor oil then?

I hope that didnt come out sounding to stupid?

Thanks in adavance

That I dont have all the answers to. Having worked with motor oil for a long time Im going to say that the GM oil is in the 30 weight range, but the only way I can find out for sure is to run an oil analysis.

I put in a 0W-20 motor oil. I have 30 weight motor oils around and even 40 and 50 weight but I felt it better to go with the 20 weight for now.

Since I have never used motor oil in the snout before I have no idea or reference as to how long the oil would last in there. That said, one quart of oil would do two or three fluid changes for the snout.

In order to determine anywhere near accurate answers to your questions I would have to run a long term study that included oil analysis and you would be looking at least a year in testing because you would want to get as varied environmental testing as you could.

Even at what I'd pay for it, Id still be looking at about $100.00 - 125.00 in oil analysis costs alone as you would want to run two to three tests on each fluid to get a well rounded picture of what is going on.

Its a closed system, but the heat would work on the oil over time and the only true way to determine when it should come out would be with oil analysis.

I did state, for the record, that in order to answer the questions accurately, an oil analysis would be needed. I also did not say that it 'feels' like a 30 weight oil

Also, I didnt start doing this because of expense. Whats the point? To find out if I can, pure and simple. GM doesnt list specs for replacement exhaust pieces, but we do that without much thought. They dont list a replacement intake, but we do that too without much question.

Do you know how many stock OEM air filters I could buy for the price of an intake? Heck, consider how many I could buy even for just the cost of a home made intake.

I mean come on, there's two sides to nearly everything.

As well, I mentioned Ive worked with motor oil for a long time. Want to guess where else the 0W-20 motor oil I selected is used. Gear boxes, transmissions, etc. So while it may not see many applications that spin quite as fast as the gears in the snout do, it is more than capable of handling it.

Speed shouldn't be an issue, turbo spin to 20,000+ RPM sometimes and all use motor oil.... I would really like to see what happens 4-6 month down the road using the 0-20w

Originally Posted by 02BlueGT

Speed shouldn't be an issue, turbo spin to 20,000+ RPM sometimes and all use motor oil.... I would really like to see what happens 4-6 month down the road using the 0-20w

Thats a good point, I had not thought about that. We'll see. Either I can figure it all out or I cant. Either way I'll have more knowledge than what I started with and most good education costs something.

I understand you were curious, Im just responding in kind to the points you bring up. I like the debate, humor me, LOL.

With my examples vs. yours, you were just comparing the cost of the oil analysis vs. buying the oil, so the examples I used are no different. Im comparing cost. I could leave the intake alone, stock, or I can put in an aftermarket one. If I change it for an aftermarket one, how many OEM air filters could I buy with the money Id spend on an aftermarket intake.

Furthermore, noticeable advantages are not limited to sound or performance. But thats another thread and a whole separate debate.

Additionally, I will say again I have worked with motor oils, gear oils, transmission fluids , etc. for quite some time so I know how to read data sheets and fluid specs and other information that can tell you what applications a particular lubricant or fluid would work well in. With the extremely limited information about the GM lubricant I have to almost solely rely on an analysis of how its used and in what environment.

1. Closed System
2. High Speed
3. High temperatures.
4. Little fluid contamination

Just those alone tell me I need a fluid that can withstand sustained high temps, probably in the high 200* range if not a tad higher. I need a fluid that is shear stable, in other words a fluid that may not use a great deal of viscosity improver's or has higher that normal HTHS characteristic, just to rattle off a couple things you can discern from such an analysis.

So while you may perceive it as playing with lubricants, and technically I suppose it is, I have not done so at all blind to the requirements. The benefits are not necessarily questionable either. Motor oil is easier to get your hands on than GM supercharger oil, at least around here. The synthetic motor oil seems to be allowing the snout to run cooler. Though I know of no heat related snout failures, Im not opposed to things running cooler because that usually means less friction.

So if I happen to find that Ron Vogel's issue was caused by something other than just use of the motor oil well then we have all learned something and grown a little and become a little wiser. If I find it was solely due to the use of the motor oil then we will be back where we started but we will still have learned something and settled a debate in the community as to which is better or which should be used and it wont require statements such as "Thats what Ive always used", "Thats what the dealer says to us", Thats what my dad used" and so on. We'll have a real world example of why either way.

Look at it this way, if Im right, we all gain. If Im not, then you get to laugh and poke fun at me and I have to take it. How much better can life get?

Hey scott, just curious. But have you tried to get your engine really hot, like running it hard. Then try to take off the SC plug? And see if your think there is pressure build up in there? Just wondering...

Nope, but I can do that and see what the result is. Thanks for that input.

I know when the wife came home yesterday evening I went out there and checked the snout and it was warm, but no where near what the blower casing is like. I could hardly touch the casing, but the snout I could hold on to for a good minute or longer before it got to the point of feeling too warm to hold on to.

Not exactly a scientific test, but I know that before the motor oil, with the regular GM lubricant the snout seemed just as hot as the case.

Originally Posted by SyntheticShield

Look at it this way, if Im right, we all gain. If Im not, then you get to laugh and poke fun at me and I have to take it. How much better can life get?

coming to the table with new ideas and testing them is what keeps this community growing

Yeah, thats kinda the approach I take. Im not afraid to be wrong or to look a little silly and pointless if it means gaining a little knowledge and learn a few things.

There are risks in all things worthwhile. And while I dont desire to destroy a snout from testing, I do have a spare and its not that much trouble to swap out if needed so why not try and learn something?

I'm curious to see this as I may be SC soon and want to keep temps down to save my L36 bottom end

Well I can tell you with a certain amount of confidence that the synthetic motor oil does keep temps lower in the snout so far. However, the effect that lower temp there in that one place, on the rest of the engine would be minimal at best.

Yeah, I wanna make a lexan spacer, and test it, but everything adds up, lower snout temps may help lower case temps a few degrees.... you know that whole synergy thing

Thats true. Thats one approach. A little here and there that adds up instead of one big drop somewhere.

Some of you guys are wondering about the pressure building up in the fluid chamber of the M90.

Have to take into account there are some changes done to the M90 over the years. All 1997-2003 are not the same, ya we know about the external extra vacuum "tree" on the outside of the 1997's, but there were some internal changes many may not know of.

Lets start with the breather nut.

If you have the breather nut, it must always stay on your snout. The snout shaft is one thing that has changed inside these M90's over the years. If there is a breather nut, then you have a vented snout shaft. Where there is a hole drilled on the y axis of the shaft. The x axis is drilled clear though the center, up to the y axis hole. This vents pressure out of the oil chamber, and the breather nut contains the fluid filled vapor and only releases vapor.

If you open your snout fill/drain plug on a non vented snout shaft, you can get a little "pufft" of air/pressure coming out of the fluid chamber. Thats normal. The blower could be removed, off the car for weeks, and still get this effect cold or hot. It does not mean your seals on the rotor shafts, behind the drive gears are bad, leaking boost into the oil chamber.

You can also get the "pufft" sound of pressure being released on a vented snout shaft style M90. This can mean that the vent hole in the shaft is clogged, or the breather nut is damaged, or clogged. Either way...normal, not a big deal if it does happen.

Vendors selling M.P.S. and include the little black Christmas tree plug should note when they do sell these, they are only to be used on a M90 with a non vented snout shaft.

How can you tell which snout shaft you have?

If you have a breather on your snout now, then keep on using it. You have a vented snout shaft. If you have a plastic Christmas tree looking plug, keep on using that, you can run a snout breather if you want, but wont do you any good. Running the plastic Christmas plug on a vented snout shaft can cause fluid vapors to leak out, and get flung by the spinning shaft.

If your car does not have a plug at all, run what you want, or remove the snout shaft from the snout and see if you have the holes drilled from the side, meaning you have a vented snout shaft.

Why did Eaton change this?

Good question Jason, why thank you Jason. Probably there was no gains or problems having a vented style vs. a non vented style. You can also figure the price difference between the two types was a big one, considering there is another hole to drill on the vented style, plus it needs a special nut vs. no extra hole, and a plastic plug.

In this picture you can see the changes. Top shaft is a NON vented snout shaft, bottom shaft IS a VENTED snout shaft. Note the hole circled in red, there is your vent to the out side.


If you have bad seals behind your rotor drive gears you can tell by a few ways. Not in boost loss, but in fluid loss. If your low on fluid, and the pulley of the supercharger is clean and dry,(meaning the snout seal is not bad) and the under side of the supercharger is clean and dry, (meaning the seal between the snout and rotor assembly is good) then its inside where the fluid is leaking.

It can, and will go out of the seals that are located behind the drive gears of the rotor assembly and on into the LIM and used inside the engine. If the fluid is continued to be ran like this, low, and for quite some time, it will go well past the stage of coming out looking like nasty tea, or bad coffee colored as many of us have seen, and will end up looking like this:


Running the fluid low, will cause bearing failure, and seals to burn up.

Hope this information clears some things up, and answers a few questions along the way.


~F~

Farnsworth you are some kinda valuable asset to this community with the information you provide. Thank you for that explanation. We may have to sticky this yet for all the good stuff it has or make a new thread with all you have contributed.

So, what is your opinion on running motor oil vs th GM supercharger oil? I have a breather nut, so there should be no pressure build up in the reservoir if my breather nut is functioning correctly, right? So is there any of the bearings or rotor pack seals that are not compatible with motor oil? I cant imagine the viton seals would have any adverse reaction. But I have seen metal incompatibilities before, mostly in gear boxes though where yellow metals can be used.

Anyway, just interested in your thoughts on the matter.