Turbo independent lubrication system. Which oil?

[haybayian]

Since the lubrication question is being discussed now the time may be right to ask my own question. I am in the process of puting together a lubrication system  for the turbo completely separate from the engine oil. i.e.  a small oil can, a 12 volt  oil pump, a pressure switch/warning light.

My main motivation (after a bit of soul searching) is to protect the turbo which I think is not adequately lubricated for high performance in stock engines. I know, I know, many of you may disagree with this statement, but I have my reasons for doing this.

Now my question to you is: in this independent oiling system of mine what would be the most suitable oil?

Thanks.

Haybayian

[jimfoo]

#1, I'd use a synthetic oil. I probably would use the same weight as what your engine uses although you probably don't have to use a diesel specific oil since it won't be getting much if any soot.

[thedeezel]

I agree with Jim, a synthetic oil will stand up to the heat better than a conventional.
My only concern would be, in a small self contained system with a 12 volt pump, I would think think the pressure would be fairly high compared to the system in your motor, I don't know if that would have any ill affects on the turbo.

[cyrus #1]

I'm sure you could restrict the flow enough for that to be a non issue.  Don't forget that you can see upwards of 80 psi oil pressure with a cold engine.  I think the system would work well but I believe you will still want to have a thermostatically controlled cooler for it.  A closed system will have no way of dissipating all of that heat.  

[myke_w]

also, oil from the turbo gets cooled in the engine (just from mixing with cooler engine lube oil), it wont in your system, so you'll need to find a way to cool it i think.

[haybayian]

also, oil from the turbo gets cooled in the engine (just from mixing with cooler engine lube oil), it wont in your system, so you'll need to find a way to cool it i think.

I agree with your points. Yes a small air oil cooler will be necessary to provide this separate lubricating system with a means to cool down. I am looking for one. Thanks.
Haybayian

[stewardc]

You really have to ask yourself if this level of complexity is really justified. What are your reasons for going to this level of complexity?
Have hi-po diesels been loosing turbos at a great rate? - No
Is complex better than simple? - No
Is an electric pump better than an engine driven one? - No
Is there anything wrong with the VW engine's oil feed to the turbo? - No

Then, why do it ?

As your signature says "Keep it simple if you can." :wink:

[fastvicar]

+1 to what stewardc said.

Now that's out of the way I'd look hard at the lube supplied with the centrifigal superchargers (i.e. ATI Procharger, Paxton NOVI).  They often use a lube that is self-contained.  I think they have a higher shear-strength spec due to the gears, but otherwise the application seems similar.

[myke_w]

you also gotta consider the oil going to the turbo comes right off the filter housing so it's contaminant free, and cooler than the oil in the pan because it uses the oil cooler, it's a cool idea, but not one I'd personally implement considering the factory way is pretty darn good.

[haybayian]

You really have to ask yourself if this level of complexity is really justified. What are your reasons for going to this level of complexity?
Have hi-po diesels been loosing turbos at a great rate? - No
Is complex better than simple? - No
Is an electric pump better than an engine driven one? - No
Is there anything wrong with the VW engine's oil feed to the turbo? - No

Then, why do it ?

As your signature says "Keep it simple if you can." :wink:

As stated in my post I understand that others may not agree with what I am doing and this is fine.

The idea that turbo oil starvation is a common (potential)problem shared by most turbos was submited to me by a friend who is a mechanical engineer working at  the national Research Council (Ottawa). What he suggested can be summed up as follows:

"Turbo Cool Down

A turbocharger is cooled by engine oil, and in many cases, engine coolant as well. Turbo's get very hot when making boost, when you shut the engine down the oil and coolant stop flowing. If you shut the engine down when the turbo is hot, the oil can burn and build up in the unit (known as "coking") and eventually cause it to leak oil (this is the most common turbocharger problem). It is a good idea to let the engine idle for at least 2 minutes after any time you ran under boost. This will cool the turbo down and help prevent coking".

In investing my time and some money in modifying the Garrett T3 oil supply is to prevent coking, as well as providing a steady flow of cooling oil independent from the engine mechanical oil pump. In my system the turbo's bearings will be oiled properly before the engine starts and after the engine has stopped (when the turbo is still running). At this stage I am investigating the use of a type of oil (probably synthetic) more suitable to high speed bearing lubrication. Your opinion on this subject will be welcome. :wink:

[haybayian]

you also gotta consider the oil going to the turbo comes right off the filter housing so it's contaminant free, and cooler than the oil in the pan because it uses the oil cooler, it's a cool idea, but not one I'd personally implement considering the factory way is pretty darn good.

This too is a good point which I was considering. So a separate oil filter it will be. No sweat.
Thanks.
Haybayian

[stewardc]

Ahaaaaaa, so coking is the issue, not lubing. The cure has been around for years. It's called a turbo timer. I've even seen a timer built into an electronic boost control. It's certainly simpler than a system that's complex, VERY subject to failure and unnecessary.

[myke_w]

I'm interested to see your setup, and understand your logic, so I'm not interested in bashing

On the coking topic, high end modern synthetic oils are pretty good at preventing this, hence the strict 502.00, 505.00 vw oil spec requirements in the newer turbocharged cars. I can tell you from personal experience that regular conventional oils are not good at handling high heat like synthetics.

I've personally changed 4 turbo's on 1.8t's in the last month and I've only ever changed 3 td or tdi turbo's due to outright failure from abuse / neglect.  I know all the 1.8t's were neglected (wrong oil from quickee lube) but who wants to pay 60 bucks for the right oil right? I have not seen a major failure like this in a car I know was run with the right oil from day 1.

Also, vw has implemented coolant after run pumps in all their hot running motors to aid in quicker cool down so the driver doesn't have to idle after driving, perhaps this could help you? perhaps you could run a water cooled turbo and run a water circuit as well? that might get complicated though.

Another thing to consider, gassers run way hotter than diesels in stock form... I'm not sure you can make a direct comparison. I've glowed the turbo on a 1.8t passat just driving down the road, but I have to practically rally race a diesel to glow it.

I would have to think that the majority of turbo failure studies are based in big trucks and passenger gasoline cars as they are more abundant than  passenger diesels. Can your researcher freind tell us what vehicles were studied in his research?

Just a couple more points to consider..  :wink:

[haybayian]

Thanks  Myke for taking the time to give my project  full deck consideration. I am appreciative of the fact that you  must know a heck of a lot more than I do about turbos and I am listening.

Yes I will provide this forum with pictures and explanations as soon as the paint dries (I have fabed some of the components). So far the system is based on: a 12 volt pump from Summit Racing (# $179.00), a small oil cooler (#$49.00), an oil filter head and filter (#$20.00, temp switch, pressure switch (2 x 20.00$), oil lines and scrap metal approximately $30.00.  It is not an expensive project and certainly not a complicated one.

I will ask my engineer friend for references. He was not (himself) doing this research however . He was speaking as if these points were common knowledge.

Haybayian.

[bevboyy]

Why not run a oil/water core? Some garretts are dual cooled. My IHI 5RHB in my old Thunderbird TurboCoupe was that. Far simpler, just need to run a tap off the coolant line to and from the turbo.