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oil feed and drain ok if not vertical?
by
flapjack
on 18 Oct, 2007 18:53
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T3 turbo oil feed / drain lines are not vertical
They are about 40 degrees off (feed at about 10-11 oclock and drain approx 4-5 o'clock) is this a problem? Since the oil is fed in by oil pressure, won't it just push it out as well?
thanks
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#1
by
jtanguay
on 18 Oct, 2007 19:17
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that sounds sort of okay to me. you really want the best oil drainage possible though. think of a steady stream of oil being squirted into the turbo, and think of the amount of hot spots if drainage relied solely on the oil being pushed through the drain hole. it may run for a while, but will likely break down after a while (if improperly clocked of course)
can you clock the turbo so the feed/drain are vertical as possible? don't forget to take into account that the engine is on a slant :wink:
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#2
by
jackbombay
on 19 Oct, 2007 09:51
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If the drain is not at the bottom you can run into a couple of problems. The oil can get aerated causing foaming and erratic oil pressure problems. Additionally, the oil can sit in turbo after shutdown and coke up.
Hmmm, the TDI in my Westfalia is installed at 50* (AHU) and the oil return line has not been changed from stock, there are no "erratic" oil pressure problems, but the oil pressure is a little lower than I would like/expect, 2700 RPM fully warm results in about 40 PSI.
I just got the van and it didn't have an oil temp gauge in it till a few days ago, but I know the oil was getting quite hot judging by the OP drop off when you ran it up big hills, as low as 32 PSI at 2500 RPM :-/
Could be an aeration issue it seems, I planned on moving the return line down to the oil pan sometime, that just got bumped way up the list of things to do.
The engine had ~45k on it when installed in the van and now has about 85K on it, the stock turbo quit with about 80K on the engine, I presumed because it had a hard life pushing the van around, but maybe I was wrong...
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#3
by
jtanguay
on 19 Oct, 2007 10:57
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if the turbo died from incorrectly positioned oil drain line... hmmm...
i guess this wouldn't be such a huge problem if the oil drain line had some sort of vacuum on it.
the 1.6TD's drain right into the oil pan, and possibly below the oil level... can this create a fluid vacuum, or more of a restriction??? i kinda like how the TDI's drain right into the block, above the oil level.
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#4
by
jackbombay
on 19 Oct, 2007 11:24
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if the turbo died from incorrectly positioned oil drain line... hmmm...
The bearings wore out, compressor and turbine wheels hit their housings at which point boost production was greatly diminished.
IMO the bearing wore out "early" (~80K on the engine turbo) because the previous owner didn't let it idle long enough before shutting down the engine. I have an EGT gauge in my Jetta and I'm surprised how long it takes to cool to 350* F if I've been driving anything closely resembling "hard" and since the vanagon is HUGE and heavy compared to my Jetta I know the EGTs are way higher for similar paced driving so it needs a lot of cool down time.
I'm installing an EGT gauge in the vanagon this afternoon so I'll be good on shutdown temps from now on.
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#5
by
flapjack
on 19 Oct, 2007 11:50
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looking at the cutaway, i feel better about the tilted feed / drain lines.
in my inexperienced opinion, i say 45 deg is ok
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#6
by
saurkraut
on 19 Oct, 2007 13:08
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The problems of not having the drain point streight down are, as Libybapa stated:
Oil stays in the the turbo, even at 350 degrees cool down stuff can coke.
I'm also wondering about oil distibution on a turbo that is not mounted verticle. There are oil restrictors to keep the turbo from robbing pressure from the rest of the engine. So the turbo is not being deluged with oil. The cavity between the bearings is rather large. I would imaging a turbo bearing houseing tilted 45 degrees would have a distict posibility of having some of the oil miss the bearings.
Oil foaming. The oil coming out a properly orented turbo is already whipped into a foam. Making it more aerated could caus the oil pan to become aerated. You are then pumping air and oil to the whole engine.
Moving the drain from the block to the pan will not solve the problem. The block drain location is probably better for the aeration concideration.
I've been running turbo cars for over 30 years and have experienced 0 turbo failures. The key is good oil and frequent oil changes. Crappy oil, and long drain intervals are turbo killers. I've had turbos survive multiple engines. The current turbo on my '79 has over 500K miles on it. The shaft has NO play. I do fully exercise the waste gates, but I rarly spend time idleing to cool things down. I do have a fairly long drive way, so that probably serves a purpose.
Good luck with running it at an angle, the deck is stacked against you.
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#7
by
jackbombay
on 19 Oct, 2007 18:28
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Oil stays in the the turbo, even at 350 degrees cool down stuff can coke.
On a hot summer day the EGT gauge won't drop much below 350 no matter how long it idles so 350 is as good as it's going to get sometimes. but hey, I'm certainly conscious of it which is more than I can say for most people.
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#8
by
jolotter
on 19 Oct, 2007 19:44
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I've spent a good while today trying to figure out how to index a K24 for installation in my vanagon. As far as I can tell from shining a little light in the oil drain, the turbo could be indexed as far out as 45 degs without oil pooling oround the drain much as the inner sides of the casting narrow to within about 2mm of the oil drain hole. Since the oil will flow out the low side of the drain, the pool of oil from the edge of the drain to the wall 2mm away, (maybe 4mm across the hypotenuse,) will be minute.
EXCEPT the oil deflector which guides the oil to the drainafter lubricating the thrust, or throwout, bearing is designed to be positioned at exactly 6 o'clock. It's a fairly loose fit, if clocked differently may fail to do that job effectively and allow oil into the compressor side.
I wish I had thought about this when my turbo was all in pieces and I could see it clearly.
When turbos fail is there a definitive cause that can be atributed to mis-clocking?
Johann
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#9
by
flapjack
on 19 Oct, 2007 20:53
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i called and asked the guys at gpop and was told that as far as oil supply, the thing would have to be close to 90 deg to fail. It's the oil drain thats the problem.
As was said already, the turbo whips the oil into a foam and it doesn't pour well.
They recommended no more than 30 degrees from vertical, so I am in for more work.
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#10
by
jackbombay
on 19 Oct, 2007 21:03
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Guess I'm screwed :lol:
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#11
by
jtanguay
on 19 Oct, 2007 22:01
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also don't forget that our engines are on a slant. take that into consideration when clocking the turbo. (if you haven't already :wink:)
i think that good oil will help make your turbo last a very very long time.
how do dry sump engines suck the oil from their turbo's? some sort of vacuum system? it would probably more hassle than it is worth to make something for our vw's though... (unless you drive on steep hills a lot :lol:)
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#12
by
Benjamin
on 20 Oct, 2007 06:17
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my turbo manual says it should not rotated more than 30°, alltough, its better when its more vertical.
Greetz, Benjamin
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#13
by
jolotter
on 21 Oct, 2007 18:43
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Benjamin:
my turbo manual says it should not rotated more than 30°, alltough, its better when its more vertical.
What turbo manual is that?
Johann
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#14
by
Benjamin
on 22 Oct, 2007 09:43
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Benjamin:
my turbo manual says it should not rotated more than 30°, alltough, its better when its more vertical.
What turbo manual is that?
Johann
i think i posted it in the FAQ previously
Greetz, Benjamin