New guy going WOT (long)

[Snailpower]

Let me say first that I do not own a turbo Buick at this time. I have raced and worked on a bunch of them though!! I am a dyed in the wool Mopar guy, but I also know there are very few automotive groups as knowlegeable as TBGN owners about power adders! I have posted this same question at Turbo Mustangs in an effort to get a knowledable answer about this issue. Here goes:
-------------------------------------------------------------------------
Heres the story (sorry so long) I run a Master Power T70 (.70 cold/.96 hot). Not long after I got the car running with the single turbo setup, once I reached about 7 pounds it started to leak oil. More on the cold side than the hot. My set up started out with 5/16 feed line for oil and a 5/8 drain, with good oil pressure. The drain is a straight shot to the pan with no restrictions. Once I started to get some oil leaking, I changed the feed line to a ¼”, which slowed the leak. I now run 9 pounds of boost and on a top end pull, I can clearly see oil smoke, and oil residue in the pressure tube.

Since the MP turbo has a warranty, I sent it to their rep in Miami for repair of the oil seals. Once there, he called and let me know that indeed the seals had gone bad. BUT, he then told me that he could not cover the turbo under warranty because the bearings in the turbo are shot. He said I have either A) an oil supply problem, or B) an oil temp problem, due to the way the bearings were colored (indicating heat stress/failure).

Heres the problem. I run Amsoil HD diesel oil. If I had an oil temp problem, the rest of the motor would show some type of sign of it. If the oil temp problem was caused within the turbo, then it would stand to reason that there would be some type of oil coking within the turbo housing, which the MP rep clearly stated the inside of the housing looked new. As far as the oil supply, I run a ¼” line without a restriction. That is a recommended line size. Granted the fitting in the turbo housing is a 90 degree fitting, but there are plenty of passages within the engine block itself that are 90 degree. How much of a difference will that REALLY make? The oil is still going to get to where it needs to be. I am not saying my setup if the best thing since sliced bread, but I find it difficult to imagine a turbo right at 1 year old, not many miles, having this type of problem already. Anyone else have this type of problem? I am starting to think that me running a T3 flange for a 366 cubic inch motor may be causing the housing to heat up to much, but then again, that would cause coking.

Feel free to fire up some ideas here. I am not buying the story he is giving me....at least not right now.....
-------------------------------------------------------------------------
Thats the long and the short of it. I have probably left some info out, so, please ask questions... I have added a pic of my car and motor, just in case some of you want to look at an old Mopar.... Thanks!!!

 

[Black Car]

Don't worry about the 90 degree elbow, Buicks have it too.
There are several other things that you maybe doing wrong.
Do you rev the engine prior to shutting it down?
Do you shut it down right after a hard run under boost?
Both of these will cause the turbo to spin at high rpm and when you shut the engine down, the oil supply is cut off. Not saying that you are doing either, just asking.
Another thing you could do is add an electric pre/post luber to the turbo or just a solenoid controlled post luber to it. Both will supply an oil supply after the engine is shut down. Summit sell ( or use to) the electric unit and I forgot who sold the other unit.
The second unit is just a metal container (accumulator) with a solenoid valve that tees into the oil supply. There is an orifice coming off the engine oil supply that feeds/fills the bottle when you first start the engine, with the solenoid open. Then when you shut down the engine, you open the solenoid to supply oil back to the turbo.

Nice Mopar by the way.

Gary

 

[scottyb]

This may be irrelevant, but I noticed you use HD Diesel oil. Someone once told me that heavier oil isn't good for the turbo, but on the other hand it clearly isn't an issue in TD's, etc. Perhaps the design of the smaller car turbos are different. My thought is that because of the weight, it doesn't flow and lubricate/cool well, and also can blow by seals.

I don't really know, but just wanted to pass the thought.

 

[Snailpower]

Thanks for the replies (and compliments!) so far. wasn't sure if I would be welcome!!

I am always very careful about my shutdown routine. So I guess the answer to the first question is no. Even the turbo rebuilder mentioned there was no coking in the housing, so that has to be a good sign.

The Amsoil I run is 10-40, but in a synthetic HD form, said to be formulated for Marine/Diesel/Racing applications. It isn't any thicker than normal oil.

I have been told that the T3 flange (T4 Housing) is not suited for cars over 2.5L and the restriction caused by the T3 flange could be causing my bearing failure. Any ideas on this? I can see the T3 causing a problem with performance, but bearing failure???

 

[rhunt]

Black Car

As an aside what should you do when shutting the car down? Let it idle by itself, rev the engine? Should know this Can you advise?

TIA

Roger

 

[rhunt]

Sanilpower

Dude:

Everyone is welcome here We all learn from each other!!

Roger

 

[Black Car]

Black Car

As an aside what should you do when shutting the car down? Let it idle by itself, rev the engine? Should know this Can you advise?

TIA

Roger

IMO, If you have been under boost (in last couple of minutes), DON'T shut the engine off. The turbo shaft is still spinning very fast and needs oil to the bearing. Let the engine idle for 3-4 minutes. The oil also removes heat from the turbo.

Gary

 

[VadersV6]

Measure thrust play and see if its different than the factory spec. Find out exactly how the bearings are shot. If its the diameter that has worn out, or the thrust walls of the bearings. That could probably lead you in the right direction and help you find out what exactly is wrong. They could have shipped it with too much/too little thrust, or you could have an imbalanced impellar or compressor wheel. Maybe the shaft is bent. It would be best next time to measure all the clearances yourself and document it before sending it to them and having them lie to you so they dont have to pay. Maybe the return hole in the oil pan is too low and its fighting with the oil in the pan for room to drain. Maybe you have crankcase pressure thats causing drain issues. Could be anything. Do you have any form of crankcase vetilation, other than breathers? Are you running a high volume/pressure oil pump? If so, maybe your return drain isnt big enough. The fact that running a smaller feed line reduced the problem could be a sign of this.
I would give kenny duttweiler a call and ask him about this. He's a very bright guy when it comes to turbos, and just about anything related to race cars.

 

[rhunt]

Cars Parts

Snail

Let me know your address and Ill send you a check or MO The Zip is
21046 Columbia Maryland. Thanks again.

Roger