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Engine Specific Info and Questions => IDI Engine => Topic started by: regcheeseman on October 06, 2010, 06:23:50 am
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Any issues with running the VNT upside down? Obviously the oil lines need changing.
I could spin the vane housing and redrill the location pins but that would send the port for the intercooler in a really silly direction.
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Here you go, some nice piccies...
First up the orientation of the compressor housing, showing the position of the outlet/port to the intercooler
(http://i492.photobucket.com/albums/rr281/regcheeseman/Golf%20in%20progress/P1020616.jpg)
the upside down oil fittings
(http://i492.photobucket.com/albums/rr281/regcheeseman/Golf%20in%20progress/P1020615.jpg)
So I just remove this circlip and I can reposition the compressor housing???
(http://i492.photobucket.com/albums/rr281/regcheeseman/Golf%20in%20progress/P1020618.jpg)
And finally a picture of the other side, just because I like it.
(http://i492.photobucket.com/albums/rr281/regcheeseman/Golf%20in%20progress/P1020617.jpg)
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would have helped a little had you told us you were running a KKK VNT.. thats a BV39 isnt it?
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I'm running a KKK VNT, it's a BV39 ;)
I haven't clocked one of the KKK VNTs. Report back what you find out.
Clocked? what do you mean? to 'clock' something over here means 'to look at' or 'to have seen something' as in "did you clock the baps on that bint"
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Clocking a turbo means to rotate the various bits the way you want them oriented.
I sort of gleaned that from the context, but from an engineering aspect, you 'clock' a machine tool like a mill using a DTI to ensure the bed is flat etc.
A dynamic rotary object would be clocked using a DTI o observe radial/axial distortion - which I thought may refer to a turbo
But searching on here, most references to clocking seem to involve marking an assembly in a fixed position to ensure correct reassembly - a reference I've never heard in the UK.
I'll give it a shot, take some piccies as well, I've previously separated the turbo halves to see the vanes, it's a new turbo so it dismantles easily.
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Turbos can't be run upside down. The oil drain MUST be within 30* of vertical down.
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Yeah, but if it's upside down, feed becomes drain.
Why wouldn't it work
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You shouldn't be touching turbos.
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Yeah, but if it's upside down, feed becomes drain.
Why wouldn't it work
The feed is oil under pressure forced through the shaft/bearing assembly, which has very little space. Try to drain oil through that and you would have a housing FULL of oil, and probably a dead turbo in no time. Just figure out how to rotate the center section around, so the drain is the drain.
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Glad to hear you again jimfoo :D.
Yeah pumping oil into the drain would push it out the seals faster than out the used-to-be-feed port.
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You shouldn't be touching turbos.
Yep, thanks for that. There's probably a lot of things I shouldn't have touched in the past but that is how people learn, your attitude doesn't help.
I'm no expert in turbos I'll freely admit, however I know a wee bit about engineering and have a passing comprehension of physics - so give it a shot I may understand.
The feed is oil under pressure forced through the shaft/bearing assembly, which has very little space. Try to drain oil through that and you would have a housing FULL of oil, and probably a dead turbo in no time. Just figure out how to rotate the center section around, so the drain is the drain.
You seem to be implying that the oil 'sumps' into the bottom of the turbo and flows back under gravity - are you sure?
Ok, bear with me, anyone who knows me, will appreciate it is my nature to question the 'facts' presented by this forum as they have been discovered to be regurgitated bunkum in the past. ;)
You have oil fed under pressure to a turbo right?
Oil passes through a bearing/oilway etc
Oil leaves turbo under pressure to return to sump - it is not a gravity drain correct? (I do appreciate the drain needs to be at a low point though for other reasons)
IF the above statements are correct will some please enlighten me what particular factors influence flow direction requirements apart from inlet/exit diameters which would be altered appropriately.
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I don't know for sure on the drain, but mine doesn't seem pressurized at all. It seems that the bearing is a restriction and has the pressure on it. After leaving the bearing the drain being a lot bigger it just looks to fall out of the drain under no pressure at all.
I could be wrong, but that is what it looks like to me.
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Indeed, that is what it 'looks' like to me, but I have little knowledge of the internal setup.
The feed side would be high pressure and high flow rate, the bearing a restrictor and the drain line at a low pressure, a very low pressure admittedly. That low pressure is a result of the viscosity of the oil, the diameter of the pipe and the flow rate.
Being an electronic engineers I see fluid flow like an electronics circuit - unlike most people who reverse the analogy to make electronics more understandable.
Basically the turbo is a resistor, I'm curious to know if there are any flow control devices (capacitors/diodes ;) ) fitted. Or is it purely a resistor?
It's all academic as I'm going to clock it anyway, I'm merely hypothesizing now. ;)
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Wow, I daresay IMO you shouldn't be touching any keyboards, at least none that allow posting on this site... Only one way to take that and I mean it even if knickers get twisted...
Sorry, but if he doesn't even know the fundamentals of how a turbo works he shouldn't be messing with them. What makes you think that because he doesn't know oiling 101 that hes capable of correctly clocking the turbo? This isn't some antique wastegated turbo, things must be aligned precisely or it won't work safely.
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... and we're here to learn from each other... respectfully and without sarcasm... be it turbos or keyboards.
Over and out!
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I can say that all journal bearing turbos that I've seen have had the pressurized oil enter the area of the bearing very similar to the way the oil enters the main or rod bearings of an engine. It then flows out from the limited space and is evacuated from the main cavity of the turbo by gravity. The turbo shaft seals are not positive seals but rather rely heavily on the proper drainage and oil slingers on either end of the shaft before the seals. If one were to pressurize the drain port I am 100% SURE that a massive amount of oil would leak out of the shaft seals when the cavity was pressurized. I surmise that it might even be enough to actually starve the shaft bearings of proper pressurized lubrication and the turbo would not last any amount of time.
That is pretty much how I understood the setup, the only item pressurizing the the oil exiting the turbo would be the flow limitations of the drain hose and sump connection. Therefore reversing the flow should pose no problems for the seals with no change in the drain setup.
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Less leakage would occur with the latter, but as the oil level rose above the shaft it would still leak out the shaft seals profusely.
Just to clarify 100% as I'll be running into something similar in my build, but if your oil return is on the top, even with nominal pressure, it will leak around the shaft?
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Vince, I flagged his post as soon as it was up and didn't comment for a day on it. I have a hard time saying nothing when someone posts rudely to a forum member I respect and without presenting any worthwhile information. I would certainly have preferred to see his post removed, but I won't sit idle for very long.
PM sent....
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Cheeseman is always messing with stuff he doesn't know anything about,.. when he starts, ha.
Fortunately, he has a steep learning curve and we all learn along with him.
The pressurised oil squeezes past the bearings and drops into an open cavity, that is basically at block pressure.
If someone fed oil into the cavity, then expected it to squeeze past the bearings, the whole shaft, bearings, seals and all would be under much higher pressure.
This has been mentioned,
I'm simply restating it in a different way.
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(big chunk of very useful turbo architecture info cut)..Much like running a jet of water under your roof shingles instead of rain naturally flowing off the roof.
Now, that is an analogy I can relate to; some weeks I was woken by the wife "what the f is that running down the wall"
(http://i492.photobucket.com/albums/rr281/regcheeseman/leak.jpg)
It transpired that a gutter discharging onto a roof at the wrong angle WILL push a hole in the roofing felt...
On a serious note, thank you for the detailed description of the internal setup, it actually gives me an understanding of what is happening, rather than accept it at face value.
Time to get clocking......pass me the big hammer and a chisel, this looks easy.
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Keep in mind your vnt actuator will now be in a different position. And hopefully not pointing at the cylinder head or you will need to make a linkage to mount the actuator up/down/or towards the firewall if you have enough clearance.
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Keep in mind your vnt actuator will now be in a different position.
VNT Actuator? No, Mr Know-nothing Cheeseman has no use for VNT actuators. ;)
Well, not a conventional actuator, my VNT is driven via Bowden cables so it's orientation is of no concern.
The whole lot is controlled and driven by self-designed micro processor circuit (http://www.vwdiesel.net/forum/index.php?topic=22213.0), of which I knew nothing about 24 months ago. ::)
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Well, not a conventional actuator, my VNT is driven via Bowden cables so it's orientation is of no concern.
The whole lot is controlled and driven by self-designed micro processor circuit (http://www.vwdiesel.net/forum/index.php?topic=22213.0), of which I knew nothing about 24 months ago. ::)
Dude. That's pimp. Gonna be sweet once it's running!
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You are obviously quite new here.
You don't know whats obvious then.
Vince, I flagged his post as soon as it was up and didn't comment for a day on it. I have a hard time saying nothing when someone posts rudely to a forum member I respect and without presenting any worthwhile information. I would certainly have preferred to see his post removed, but I won't sit idle for very long.
I think you need to spread the cheeks a little further apart, I can still see an open nostril.
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I think you need to...
Zero-tolerance for blatantly disrespectful posts... *and* you were warned once (this time around?!)... account disabled.
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Keep in mind your vnt actuator will now be in a different position.
VNT Actuator? No, Mr Know-nothing Cheeseman has no use for VNT actuators. ;)
Well, not a conventional actuator, my VNT is driven via Bowden cables so it's orientation is of no concern.
The whole lot is controlled and driven by self-designed micro processor circuit (http://www.vwdiesel.net/forum/index.php?topic=22213.0), of which I knew nothing about 24 months ago. ::)
Like the chevy duramax lmm vtn? they adjust the vanes to act as an engine brake too. This is a very good build I'll keep my eye on this thread.
Oh, and, there is always a way, you just need to find out how.
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The new Audi turbos are actually controlled entirely by an electronic servo. Maybe this would be even better than bothering with vacuum on non-ecu cars.