Miata Turbo Forum - Boost cars, acquire cats. - alternative turbo lubrication

- Insert BS here (https://www.miataturbo.net/insert-bs-here-4/)

- - alternative turbo lubrication (https://www.miataturbo.net/insert-bs-here-4/alternative-turbo-lubrication-44485/)

alternative turbo lubrication

chatting with a guy at work about his truck, he asked me if a turbo could be lubricated with atf instead of engine oil. i really don't know so, would it work with any kind of longevity?

I always put half-a-quart in my engine and drive the car 1 mile before I change the oil... Its a cheaper way to clean out the engine, ATF has detergent in it, all transmission fluids do. So I dont see why not.

I'd be more worried about the thermal breakdown characteristics of ATF fluid at turbo operating temperatures. Also, how would you even feed it to the turbo if you're not running it off of the engine.

Only good use for ATF is cleaning shit..

No, you wouldn't want to lubricate a turbo with it.

Quote:

Originally Posted by rccote (Post 530881)

I'd be more worried about the thermal breakdown characteristics of ATF fluid at turbo operating temperatures. Also, how would you even feed it to the turbo if you're not running it off of the engine.

I had a customer come into the performance shop I worked at asking all kinds of strange questions about a turbo setup he was doing. It was a rear mount turbo, and he was going to make his own oil tank and electric pump in the rear of the car to lubricate the turbo. So it certainly isn't unheard of.

Hydraulics & Turbines

There is much similarity between lubricants used in hydraulic systems and those used in turbine applications; indeed Hydraulic Oil & Turbine Oil are sometimes interchangeable but they both fall in to the category of R&O - Rust and Oxidation inhibiting oils.

Turbine applications fall in to three categories; Steam, Industrial and Aero Derivative.

Steam turbine lubricating oil can last many years in service and are seldom changed. Not much goes wrong in service and the make-up rate is low. The major contaminant is water from condensation around the steam glands or other parts of the system. Water vapour condensing in the head space of storage tanks can cause unusual secondary corrosion contaminants which will accelerate further degradation.

Industrial Turbine Oil Industrial turbine oils are more stressed in service, mostly as a result of higher bearing operating temperatures where the oil is often used to cool as well as lubricate within the turbine frame. Sump sizes are quite large and again, if carefully managed, the oil will for extended periods. TAN (Total Acid Number) and viscosity are the major tests but water, especially from storage tanks and particulates are also worth consideration.

Aero derived gas turbines place considerable stress on the oil, often necessitating the use of synthetics. Bearing temperatures are much higher and sump sizes are small. TAN is again a primary monitor, both from oxidation and hydrolysis of the synthetic oil. The Kittiwake viscosity test is used on aircraft maintenance stations searching for fuel dilution, a tell tale sign of microcracks in the oil cooler groups. The insolubles test is also used for monitoring black oil, a failure mode seen on very highly stressed military aviation turbines. Traditional vibration monitoring is insensitive for bearings buried deep within the turbines. consider ANALEX RS Oil Condition Monitroing Equipment technology for this critical application that will give an instantaneous warning of even slight bearing damage.

Hydraulic oil systems share commonality with the above applications. Additionally, particles will cause increased wear and high pressure systems are very intolerant of water. TAN is indicative of thermal stress on the oil, leading to gum and lacquer build-up, especially on control spools.

Source: Hydraulics & Turbines

On the one hand, if I were going to bother with creating a separate oiling system for the turbocharger, I think I would run an oil in it which was intended for intermittent-duty gas turbines.

On the other hand, automotive turbochargers are intended to be lubricated by the engine's oiling system, and they seem to have earned a reputation for performing quite well in this environment when a good quality oil is run, and replaced on a regular schedule.

Quote:

Originally Posted by rccote (Post 530881)

I'd be more worried about the thermal breakdown characteristics of ATF fluid at turbo operating temperatures. Also, how would you even feed it to the turbo if you're not running it off of the engine.

his idea was to mount the turbo up by the trans and feed it just like the engine would with oil, you know automatic transmissions have a pressurized oil cooler lines that you could tee off of. we talked about the temperatures too, he was convinced his transmission fluid was much cooler than his engine oil and also had somewhere around twice the capacity.

how much does a turbo heat up the oil flowing through it?

Aerodyne turbos ask for(I think, but I'd have to check the bottle at home) SHC600 synthetic bearing oil. Some sort of industrial lube for, um, industrial gearboxes/spindles/whatever. Anyhoo, those turbos had/have their own lubrication system and oil supply. Then again one can look at their reliability record and be somewhat less than impressed. Not sure how many of those failures were really driven by the lubrication system, though. Shrug.

Quote:

Originally Posted by the_man (Post 531183)

self contained lubrication would make things even easier. even with a turbo in the engine bay you could now mount it lower without worrying about oil draining.

Looking at Mobil 1 ATF vs. 10W-30 product sheets, the motor oil is more dense and viscous at operating temps, and also has a higher flash point for whatever that's worth.

Mobil 1 Synthetic ATF
Mobil 1 10W-30

whoa shit im a tard, I thought you meant priming, not feeding it ATF!!! No way, its definitely not a good idea. Exhaust temps exceed above average temps of automatic transmissions... believe me I know. Not only that, ATF needs a consistently clean environment, and since there is always the risk of carbon build up from anything exhaust, its not a good idea. Your better off running a separate oil pump and reservoir with oil and get water cooling on top of it.

Alternative turbo lubricants and methods could certainly work but only if the turbo he wants to use is designed for it. Taking ATF and running it through turbo bearings and housing designed for motor oil isn't going to work. He wouldn't use ATF in the motor instead of oil or use motor oil instead of ATF in the tranny.

Quote:

Originally Posted by Pen2_the_penguin (Post 531314)

this is more or less what i suggested from the get to. only i would just have like a 1 gallon baffled tank with maybe 2 quarts of oil being pumped with an electric pump through an oil cooler and then into the turbo where it would gravity drain right back into the tank. there really is tons of room up under there.

Quote:

Originally Posted by Mach929 (Post 531385)

i would just have like a 1 gallon baffled tank with maybe 2 quarts of oil being pumped with an electric pump through an oil cooler and then into the turbo where it would gravity drain right back into the tank.

Ok, so that I understand correctly, the question revolves on the use of a discrete oiling system especially for the turbo consisting of a tank and electric pump, said system being entirely separate from both the engine's oiling system and the transmission's oiling / hydraulic system?

(In other words, This?)

If that's the case, then I suppose my only question (over and above what's been discussed in the aforementioned link) is how on earth did ATF ever come to be considered in this situation? Why would it be considered superior to either a synthetic engine oil or a proper turbine oil?

Quote:

Originally Posted by Joe Perez (Post 531404)

LOL, it was only his idea, i guess he figured it would be less complex with less parts. i figured it was a bad idea but i honestly didn't know if atf would be acceptable to run through a turbo

Quote:

Originally Posted by Mach929 (Post 531418)

LOL, it was only his idea, i guess he figured it would be less complex with less parts.

Less complex than two pieces of hose? :hustler:

Quote:

i figured it was a bad idea but i honestly didn't know if atf would be acceptable to run through a turbo

I doubt whether there is anybody, on any forum, who can actually answer this question accurately and provide evidence to support their answer. I'm not saying that the internet is full of idiots (well, nvm), but merely that I can't imagine that anybody has ever actually tried running ATF through a turbocharger and driven on that setup for any length of time.

Go forth, and be a pioneer!

If you want to test it out with no risk to a car, you could buy a cheaper ebay turbo and construct a turbojet with it :). They still require an oiling system, and I'm sure that the burning LP gets plenty hot.