Twin turbo Oil in intercoolers an air filters

[porsche 930twin]

Hi all have the flat fan fitted and engine running but before we head back to the dyno I have to sort this issue out. I have been getting oil in the intake pipes, plenum and air cleaners as you may notice in one of the pictures the amount of oil on the ground under the turbos... I have changed oil line restrictors from 1mm to .075 I am feeding oil to turbos from cam lines (see pic) do these lines have greater oil pressure then say rear oil sender unit?? I have checked the scavenge pump by putting a clear hose into a container of oil and started the engine up and it drained it pretty quick... So next I removed turbos and sent them of to have seals checked but turbo guy assures me the will be ok...
Where to next is there something I am over looking...

[moty]

Hello i had the same issue with my car attach the answer from the doctor with the recommended medicine.
1. Does the oil outlet on your turbo have a "catch-can"? The catch-can is usually a small tank that is mounted beneath the turbo and allows the hot oil from the turbo drain into the tank. These are needed on a Porsche because set-up because the turbo is mounted quite low and the oil from the turbo need to gravity drain away for the turbo. You can get away without a catch-can - but I always recommend that they are fitted.

2. Does the catch can have an air vent? There should be 2 hose connections on the catch can. One for the scavenge pump and one that vents back to the top of the engine case, or oil tank. THIS VENT LINE IS CRITICAL on any turbo set-up with an electrical scavenge pump. The TurboWerx pump is self priming and can run with minimum oil in it without burning up. As the electrical scavenge is a fixed displacement pump and it runs at a fixed speed, it will always try to pump the same amount of oil every minute (like ~3 gpm). As the oil being supplied to the turbo is coming from the engine oil pump, which is driven off the crankshaft, it is supplying different amount of oil to the turbo, depending on engine RPM. Therefore the amount of oil coming into the turbo changes depending on the engine rpm, but the oil being sucked away from the turbo with an electrical scavenge pump is constant (~3 gpm). If you do not have a vent line the scavenge pump will create a vacuum in the turbo center section - and pull air through the seals. Over time this can damage the seals and create leaks. All turbo manufacturers require that the pressure in the turbo center section remains at atmospheric pressure - which is why you should have a vent line. In the situation described above where the oil coming into the turbo is less than the oil being sucked out of the turbo - the scavenge pump will suck air through the vent line and and mix this air with the oil.

3. Are you running a ball bearing turbo or a journal bearing turbo? If you have a ball bearing turbo you need to make sure the appropriate oil restrictor is installed on the oil supply to the turbo center section. These are normally supplied with the turbo - but it would be good for you to check that it has been installed. They size of the hole in the restrictor is normally less than 1mm.

[Mike Billings]

I have a tee on the cam oil lines for turbo oiling just as you do. With a restrictor. Not having any problems.

Would suggest looking elsewhere for the source of the problem.

[Porsche 935]

[SBK930]

Can see the oily spots on the ground below the turbos.
But where is the oil leaking from ?
Maybe a clue there.
I have had a lot of the same issues after having my turbo rebuilt and the oil would seep out from where you have the air filters attached to the compressor side.

[Porsche 935]

If the oil lines are full up to the seals, it can seep into the compressor housing. Upon start up it will push oil into the intercooler. Thus the reason for the catch can, allows oil to drain and not saturate the seals. Some turbos have dual seals for this reason.

[full quack]

Since the turbo's are basically the lowest point in the oiling system, I agree that you most likely either need an oil catch can, or an electric scavenge pump that continues to run for 30 seconds or so after you shut off the engine.

Mark

[porsche 930twin]

Hi all thanks for the replies I am running the standard 930 scavenge pump and also a catch can gravity fed from each turbo but no vent hose on the catch can see pic It seems the oil on the right turbo is leaking past the compressor side into intake pipes and dripping from air cleaner and on the left side it seems to be leaking on the exhaust side and then leaking into exhaust pipe this is only my opinion I still think the ceramic seals on Turbos are the problem

[Porsche 935]

My factory pump gave out at one point and installed an aftermarket billet one in the factory location. Also the original oil feed line for the turbos has a check ball to prevent the line from draining when the engine is shut off. I installed a AN banjo bolt in replacement of the factory one and ran -3 lines to the turbo. Found out -4 are too big.

[GJF]

You want to feed the turbos from the cam towers as they get oil after the crank. Oil pressure will always be the same throughout the engine. Vented catch can for turbos that low for sure. I always run 1 way check valves in line to each turbo so after shutdown it will not allow any kind of drainage after shutdown to the turbos and not allowing the oil to back up as the scavenge is no longer working with the engine off. If the oil level backs up into the CHRA that is when it can leak past the seals.

[SBK930]

Originally Posted by porsche 930twin

Hi all thanks for the replies I am running the standard 930 scavenge pump and also a catch can gravity fed from each turbo but no vent hose on the catch can see pic It seems the oil on the right turbo is leaking past the compressor side into intake pipes and dripping from air cleaner and on the left side it seems to be leaking on the exhaust side and then leaking into exhaust pipe this is only my opinion I still think the ceramic seals on Turbos are the problem

Hate to say you are probably on the money.
Remove the line out from the core assembly and if there is little oil present it cannot be backing up and seeping into the compressor or turbine housings.
A breather is definitely advisable to mitigate pressure.
My 7006 turbo was sent back to the rebuilder 4 times and the core assembly was rebuilt and honed for oversize bearings after it had detonated and each time they said that it was good and ran it on their VSR. Each time I installed it I had oil seepage from either or both sides.
At this point I appear to have fixed my turbo problem by purchasing a new 7200.

Steve.

[full quack]

Did not even register that those tiny little units are your catch cans, thought they were simply fittings.

Humm...not sure if they are large enough to get the job done?? Maybe it is just a trick of the photo that makes them look so tiny???

Others better in the know, will chime in I'm sure.
Best of luck finding a solution, damn frustrating cleaning out the intake/intercooler/exhaust!

Mark

[smurfbus]

That's another engine which works? Did not see any cans on SBK's pics

[SBK930]

Originally Posted by smurfbus

That's another engine which works? Did not see any cans on SBK's pics

Hi smurfbus,

I have the original catch can to stock scavenge with vent.

Nearly drove me crazy thinking that the oil circuit was the issue as the rebuilder continued to tell me. Tried everything I could to find the problem with the circuit and it was the turbo all along.

Steve.

[smurfbus]

My bad, I meant I did not see the OP's (porsche 930twin) catch can which he said is in the pic "a catch can gravity fed from each turbo but no vent hose on the catch can see pic"

I have had a big catch can from day one but on track It had a habbit of wooshing the oil up to the breather outlet in the air filter. I had to install a 1.5mm restrictor before the turbo oil intake.

[Alan L]

SBK930 - you don't have a turbo support bracket? All the turbo weight and vibration is on your expensive headers?
Regards
Alan

[SBK930]

Originally Posted by Alan L

SBK930 - you don't have a turbo support bracket? All the turbo weight and vibration is on your expensive headers?
Regards
Alan

Hi Alan,

Not to worry about it mate as the pic is without the Monty exhaust fitted and the bracket bolts onto the turbine side with a gasket either side.

Steve.

[Alan L]

I figured after posting, your turbo had no studs. So was probably work in progress.
Regards
Alan

[SBK930]

Originally Posted by smurfbus

My bad, I meant I did not see the OP's (porsche 930twin) catch can which he said is in the pic "a catch can gravity fed from each turbo but no vent hose on the catch can see pic"

I have had a big catch can from day one but on track It had a habbit of wooshing the oil up to the breather outlet in the air filter. I had to install a 1.5mm restrictor before the turbo oil intake.

Funny that smurfbus,

As the rebuilder also told me I must need a restrictor for the oil “in” line.

Makes sense why the original catch can has the large cylindrical tube above the catch tank that the vent runs from.

Steve.

[SBK930]

Originally Posted by Alan L

I figured after posting, your turbo had no studs. So was probably work in progress.
Regards
Alan

All good Alan,

Just happy to be making progress.
Wish I had headers however I am running stock manifolds with stock heat exchangers. Somewhere along the line the exhaust was cut and modified more than once.

ps: I have ordered a fuel accumulator and fuel filter and waiting on their arrival.

Checked the fuel pumps and both appear to be good.

Steve.