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Quote:
Originally Posted by turbo owner View Post
^^^^
Anybody down under have a loaner to do a test?
Now that would be cool.
I have not thought of that turbo owner.
I may even run that by the rebuilder and see if they are willing to loan me one.
Old 06-03-2017, 07:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #141 (permalink)
Mighty Meatlocker Turbo
 
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^^^

That is a great idea, TO.!
Old 06-03-2017, 07:54 PM
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Make sure the oil tank is free of debris, with the suction from the pump a chunk floating around in the tank could cause a temporary blockage.

Also make sure the line to the pump is clear.
Old 06-03-2017, 08:22 PM
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Is it possible for the engine oil pressure that is shown on the dash gauge be different to the oil pressure being fed to the turbo.
I am thinking of placing a gauge inline to the turbo.
Clutching at straws here.
Old 06-04-2017, 01:08 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #144 (permalink)
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Those gauges work pretty well, and the numbers you have quoted sound about right. Clutching at straws. Remember, the brains trust correctly stated oil pressure not the problem.
Not sure why you are chasing for leakdown numbers. But your TDC marks start at Z1 (TDC #1 firing) then at 120 deg intervals on the timing pulley you will find another notch. This is your next TDC - as per the firing order. Rotate with pulley spanner on pulley nut (all plugs out). When at the mark apply the compressor pressure for the leakdown unit. I use 100psi and calibrate off the first gauge. There is a warning here - if the engine is not right on TDC it might want to rotate suddenly. But I have never had it do this and no longer even hold the pulley spanner in case.
I have a home built leakdown unit. Am not in NZ right now, back early July. If you are still stuck, will post it to you.
But I seriously think you have come to the end of the road with these turbo guys. As before, I would contact the Perth guy, or Turbokraft or Brian. I have dealt with both the latter, as have heaps here. You will not have these issues. Yes it costs more, and the freight is a killer. But they deal with these items all the time and know the problems, and the unit will come trouble free. Having said that I had a trashed 7006 recently rebuilt here by my local turbo guy, who is no dummy, and no issues.
Regards
Alan
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-04-2017, 02:27 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #145 (permalink)
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What weight oil are you running?

Roughly how many miles on this current oil?

What is the idle speed of your engine?

Have you inspected the breather hose from the engine to tank, tank to air filter, looking for obstructions?
Old 06-04-2017, 01:53 PM
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Quote:
Originally Posted by Jim2 View Post
What weight oil are you running?

Roughly how many miles on this current oil?

What is the idle speed of your engine?

Have you inspected the breather hose from the engine to tank, tank to air filter, looking for obstructions?
Hi Jim
15w50 synthetic
New
Around 800rpm
Hoses appear clear
Scavenge oil circuit functioning well
Engine oil pressure good
New air and oil filters
Oil tank appears to be clean

Old 06-04-2017, 02:27 PM
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Quote:
Originally Posted by Alan L View Post
Those gauges work pretty well, and the numbers you have quoted sound about right. Clutching at straws. Remember, the brains trust correctly stated oil pressure not the problem.
Not sure why you are chasing for leakdown numbers. But your TDC marks start at Z1 (TDC #1 firing) then at 120 deg intervals on the timing pulley you will find another notch. This is your next TDC - as per the firing order. Rotate with pulley spanner on pulley nut (all plugs out). When at the mark apply the compressor pressure for the leakdown unit. I use 100psi and calibrate off the first gauge. There is a warning here - if the engine is not right on TDC it might want to rotate suddenly. But I have never had it do this and no longer even hold the pulley spanner in case.
I have a home built leakdown unit. Am not in NZ right now, back early July. If you are still stuck, will post it to you.
But I seriously think you have come to the end of the road with these turbo guys. As before, I would contact the Perth guy, or Turbokraft or Brian. I have dealt with both the latter, as have heaps here. You will not have these issues. Yes it costs more, and the freight is a killer. But they deal with these items all the time and know the problems, and the unit will come trouble free. Having said that I had a trashed 7006 recently rebuilt here by my local turbo guy, who is no dummy, and no issues.
Regards
Alan
Thankyou Alan.
Old 06-04-2017, 03:30 PM
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Quote:
Originally Posted by Jim2 View Post
What weight oil are you running?

Roughly how many miles on this current oil?

What is the idle speed of your engine?

Have you inspected the breather hose from the engine to tank, tank to air filter, looking for obstructions?
Jim2, if he can blow oil thru the turbo 'seals' at approx 2 psi pressure, there has to be something seriously wrong with the build/tolerances. Should not happen. I wonder if there is a problem with the shaft - but we can only guess from here. A rebuild specialist would have to take a look.
SBK, I will email my turbo guy who did my 7006 rebuild. this required replacing the shaft, once he opened it. I will ask for his helicopter view of where the issue may be.
You are prob just as well off to use the guy in perth, but the postage to NZ is prob about the same.
Regards
Alan
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-04-2017, 05:31 PM
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Quote:
Originally Posted by Alan L View Post
Jim2, if he can blow oil thru the turbo 'seals' at approx 2 psi pressure, there has to be something seriously wrong with the build/tolerances. Should not happen. I wonder if there is a problem with the shaft - but we can only guess from here. A rebuild specialist would have to take a look.
SBK, I will email my turbo guy who did my 7006 rebuild. this required replacing the shaft, once he opened it. I will ask for his helicopter view of where the issue may be.
You are prob just as well off to use the guy in perth, but the postage to NZ is prob about the same.
Regards
Alan
You are probably closer,
I thought the shaft was part of the turbine wheel which had to be replaced due to it being damaged by a piece of air injector nozzle that fractured off.
What I fail to understand is if all the plumbing was blocked (for whatever reason) yet there is good oil flow through the turbo and the scavenge system works, it can only be the turbo, surely.
Thanks again Steve.
Old 06-04-2017, 05:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #150 (permalink)
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Too light of oil weight could flow excess through turbo then overwhelm gears in scavenge pump. 15-50 is fine.

Old used oil goes thin, causes same issue I mention above.

Idle speed, remember scavenge pump is run from a cam, therefore half crank speed. If idle is too slow yet idle oil pressure is high when oil is warm and thin, scavenge pump can be overwhelmed. 800 idle rpm increased to 1000 rpm is a 25% increase, with an equivalent increase in scavenge pumping capacity.

Alan, turbo seals are by no means positive. They rely 100% on gravity to drain oil, along with a bit of slinger affect. 2 psi crank case pressure would probable be an issue. In fact my 993 had about half the breather vent area of a 930, pushed oil out both compressor and turbine ring seals until I improved the crankcase ventilation to match that of a 930.

I'm no expert, just throwing out ideas in order try and narrow the issue down.
Old 06-04-2017, 08:28 PM
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Quote:
Originally Posted by Jim2 View Post
Too light of oil weight could flow excess through turbo then overwhelm gears in scavenge pump. 15-50 is fine.

Old used oil goes thin, causes same issue I mention above.

Idle speed, remember scavenge pump is run from a cam, therefore half crank speed. If idle is too slow yet idle oil pressure is high when oil is warm and thin, scavenge pump can be overwhelmed. 800 idle rpm increased to 1000 rpm is a 25% increase, with an equivalent increase in scavenge pumping capacity.

Alan, turbo seals are by no means positive. They rely 100% on gravity to drain oil, along with a bit of slinger affect. 2 psi crank case pressure would probable be an issue. In fact my 993 had about half the breather vent area of a 930, pushed oil out both compressor and turbine ring seals until I improved the crankcase ventilation to match that of a 930.

I'm no expert, just throwing out ideas in order try and narrow the issue down.
Hi Jim,
Thanks,
Crank case oil pressure is around 40 psi at cold start, and then when at operating temp is around 15 psi. This is at idle. The turbo has run at these pressures fine for years. The oil that runs through the turbo is efficiently being circulated by the scavenge pump, as the pump more than keeps up with the oil flow when cold and keeps pace when oil is hot but is more efficient under load when hot. I still have the original drip tank that is vented to the air cleaner box. Which is leaving me struggling to understand where the excessive pressure could come from to force oil past the rings.
This turbo has got to be ...............well POO!
Old 06-04-2017, 09:14 PM
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Jim, The 2 psi I refer to is SBK blowing into the oil feed pipe to the turbo. And seeing oil weep out. This is the pipe that feeds the turbo under normal engine oil pressure. So you would have to conclude the issue is in the turbo if it weeps under a pressure of 2psi? - which is about as hard as you can blow (Rawkees excepted).
SBK has rigorously shown the scavenge pump more than keeps up.
So, we are back to the turbo?
SBK, yes the wheel and shaft are one (I think it is the intake wheel?) . I had to replace as a unit when my shaft was damaged. Maybe they got a Chinese one?
Waiting to hear from my turbo guy who rebuilt mine.
Regards
Alan
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-04-2017, 11:16 PM
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Quote:
Originally Posted by Alan L View Post
2psi? - which is about as hard as you can blow (Rawkees excepted).




- yer comment had me rolling, Alan - nice work, bro!
Old 06-04-2017, 11:24 PM
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SBK, maybe ditch the 7006 and enlist Rawknees?
Alan
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-04-2017, 11:30 PM
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^^^

Or another option would be for Steve/SBK to employ your mighty lips as a vacuum booster to the oil scavenge system?!?!

See Steve, we'll get this problem field dayed and squared away for you yet!
Old 06-04-2017, 11:36 PM
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Steve,
This is the reply from my turbo guy. I forgot to tell him turbo was working fine before piece of metal trashed the blades. I emailed him again with that and his reply was has to be internal issue in turbo and basically only measuring everything would tell. Here is his original reply. Regards Alan;

The biggest issue we come across, presuming all internal clearances are correct is the inability of the oil feed into the turbocharger to drain away freely and fast enough. This is either one of two things. 1 too much oil being feed into the turbocharger (excessive oil pressure or volume) or 2 the oil is not able to drain freely from the bearing body drain with out any resistance. (Engine crank case pressure, restricted drain passage) The oil sealing of the K27-7006 is by a piston ring at both the compressor and turbine end of the turbocharger. Both these piston rings run end gaps (normally .003” to .006”) so if there is flooding or pressurisation of the bearing housing then oil will seep out the piston ring gap. If your friend is blocking the oil drain and pressurising the oil feed with oil in it then it will force oil past the ring gap. This is exactly what will happen while on the engine if the drain has any form of restriction including crank case pressure. Being a 930 I would personally be checking the scavenge pump for the turbocharger accumulator bottle that is mounted below the turbocharger. If this scavenge pump is not scavenging enough oil away then this is exactly what can happen.
Once again I can only presume the internal clearances are correct. The K27-7006 is what we call a large component slow turning turbocharger so all cleanses, oil pressure, oil volume; oil drain, oil scavenge, crank case pressure etc need to be correct.
Hope this is of help.
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-05-2017, 06:25 PM
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Alan, that is what is so troubling and confusing about SBK's issue - way back when it first happened with the newly rebuilt unit, he performed the standard scavenge system check (posted vid, even) as advised here, and the system was shown to work perfectly.
Old 06-05-2017, 06:35 PM
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Here is my turbo mates latest reply, but I think it all points to having to get the turbo checked out by somebody else. Regards Alan.

Depending on what was done for the repair of the turbine, most repairs I have seen on the k27 turbine shafts create an out of alignment in the shaft. This can also be through the fusion weld that welds the turbine vane head to the turbine shaft not always visible until temperature is applied during operation. This is also why I replaced your turbine shaft and did not attempt a repair. I would look at replacing the turbine shaft with a genuine new unit and VSR balancing the unit.
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83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-05-2017, 07:56 PM
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Not only that I also removed the scavenge pump, made a dowel/die to engage where the cam would locate and spun it with a drill to check it was functioning well. It was.
I did the scavenge test again with the 3rd rebuild and ran it until operating temperature was reached with the engine oil pressure showing around 1 on the dash pressure gauge or about 15psi.

Even the turbo guys said it should handle 60psi. They now want it back and are going to have another shop do a diagnostic on it. They are as confused as I am.
I also mentioned here that I was considering placing an in line oil pressure gauge set prior to the turbo intake to see what pressure is registering there. So far no one here has commented to say whether or not it has been done or if it would be a good idea.

It just makes no sense if the turbo is built correctly and shows no issue when VSR (bench tested) and it really only has oil being fed into it and the oil is being pumped away from it that it should keep failing.
Like I have also said before I am freaked out about purchasing a new turbo from Chris only to find it does the same thing due to there being an uderlying problem that I have not been able to identify.

Thank you Alan for taking the time to speak to your turbo guy and posting his response.
Old 06-05-2017, 07:58 PM
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