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1980 242 GT. A reasonable project.

FWIW, I'm running a 0.035 restrictor and AN3 line. The AN3 vs 4 should reduce oil flow as well. Obv the restrictor is the easiest change.
Not sure where I was going with that.
Same turbo, same engine.
I smell a whiff of oil every once and a while when coming to a stop. No visible smoke.
 
Yes, ideally you want about 45 psi gage (3 bar) max oil pressure after the restrictor, just upstream of the turbo. It's possible to tee in a gauge if you are using an unrestricted oil inlet fitting that has a separate restrictor piece that screws into the top - just unscrew the restrictor, install your custom tee fitting for the gauge, then reinstall the restrictor on top of that.
 
Yes, ideally you want about 45 psi gage (3 bar) max oil pressure after the restrictor, just upstream of the turbo. It's possible to tee in a gauge if you are using an unrestricted oil inlet fitting that has a separate restrictor piece that screws into the top - just unscrew the restrictor, install your custom tee fitting for the gauge, then reinstall the restrictor on top of that.

Seems like that would be pretty easy to rig up. Might be a good diagnostic tool.
 
I ordered some fittings and hose so I can tee a gauge into the feed line.

I've yet to come across an oil restrictor smaller than .030"... have you guys seen anything available? /edit: McMaster offers 1/8 npt restrictors down to .010".
 
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I ordered some fittings and hose so I can tee a gauge into the feed line.

I've yet to come across an oil restrictor smaller than .030"... have you guys seen anything available? /edit: McMaster offers 1/8 npt restrictors down to .010".

ATP has undrilled bolt on AN3 adapters. You could probably order one, get a few small drills and work your way up with the oil pressure gauge.

Good deal. Hopefully the post-restrictor pressure tells a story that correlates to the smoking, and is simple to rectify.

It is strange that 0.030" is the smallest turbo-specific oil restrictor for sale anywhere online. That's been my experience as well. Nice find on the McMaster parts. Doug's suggestion is a good one too - you could dial it in very precisely with restrictors drilled yourself, if results with the McMaster parts are promising.
 
Alright, I rigged up a pressure test gauge in the feed line after a .035" restrictor. Here's what I found after a quick test in the garage.

Immediately following cold start
Oil pressure 1.8 bar @ 1100rpm (warmup idle)

After engine and oil are hot
Oil pressure .75 bar @ 800rpm (idle; pictured below)
Oil pressure ~2 bar @ 4500rpm

If my hot oil pressure at idle is already sitting at 10psi, I'm guessing I don't really want to be restricting oil flow more than this. Do I still really need to take it for a drive and see what pressure looks like near redline (7000rpm) to really know if I'm in the right ballpark for oil pressure?

43564999224_12c514ee3d_b.jpg


https://youtu.be/YxwzuYT8_Tw
 
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Yep, those measurements are all after the restrictor. It's much higher pressure before the restrictor (because whiteblock).

edit: my bad, just noticed I accidentally said "before" instead of "after" in my post.
 
Well that's pretty good then. You should put your gauge on the return line. I'm still curious what your crankcase pressure is. It would be interesting to know the oil pressure drop across the turbo anyway.
 
Looks reasonable. I don't think you need to take it for a drive necessarily, but you could rev the engine up near redline in neutral to see what your high-rpm pressure looks like. Those TurboMaster guidelines are basically the same as official Garrett, just converted to bar. They are just guidelines though. You may have leakage at lower oil inlet pressure if your crankcase pressure is high enough or if your inlet depression is low enough (off boost, with a dirty or restrictive air filter...for example). It's really about oil flow through the turbo (in & out) and the air pressure differential across the seals on either end of the turbo.
 
Air filter is large and fairly new. Previously I didn't think I had blowby issues, but just I started taking a closer look around and noticed that there is actually some oil being pushed out around the oil cap. When I removed the oil cap, there was positive pressure (enough to immediately fill a glove and keep it filled. It *seemed* like removing the filter element from the ProVent reduced the pressure, but frankly it's hard to tell.

Will inspect closer, and potentially test compression. :run:
 
I just tested compression. Results are even, but perhaps a bit low. I have a small battery so it doesn't turn over very quickly and the engine was warm, but not hot.

Volvo spec for b5234t is 1.1-1.3 MPa or ~159.5-188.5 psi.

29351502267_39edcae09c_b.jpg
 
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Those have a nice tight distribution..... did you take those with your throttle fully open whilst cranking?
 
With the oil capacity of the whiteblock, can you run a short test on the turbo by running a gravity drain external to the engine (so there is zero back pressure influence on the drain). You've established the pressure is proper on your oil supply, correct? If your turbo again bypasses oil, that would only leave one suspect I believe.
 
Hmm, the tricky part is that I wouldn’t be able to tell right away. It takes a fair amount of driving to see what’s going on.

Next I’m going to take the car for a drive with the ProVent filter removed to see if that was affecting things, but for that I need the weather to clear up.
 
Hi man and props to you for this mad project.

About your oil problem, here is my story, it could give you some ideas : i just finished a redblock build with an HY35. Basic support mods.
Removed the breather box and replaced it with a plate and nipple, with a hose that goes upstream of my turbo inlet.
First start, smoke everywhere in the garage and after driving a few miles, an engine bay covered with oily dust.
I thought : engine must not be oil proof, lets change every gasket : cam cover, oil filler, oil dip stick.
I started the engine : i literally smoked out the whole block. Worse than before.

I tried to unplug the turbo oil return to see if the drain was clogged. At idle, the flow was flushed fast enough so no problem here (or so I thought).

Next test : i let the breather hose comming out of my custom nipple, vent to the atmosphere.

Problem gone.

Now my analysis is : bottom end was seing some pressure (unknown milage engine).
At first (old gaskets), some of this pressure was pushing out through the gaskets, giving me the oily engine bay.

Then it hit me : when i changed the gaskets, the only way this pressure could exit was the turbo. The pressure was getting to the turbo through the oil return.
And this is why, when i started it again, there was much more smoke comming out the exahsut, and more oil in the turbo inlet and pipes.

So you might wanna give it a try, venting your engine to atmosphere, while giving it the beans.

Another thought : my turbo oil return is too small. Holsets love oil and i should have gone with a 19mm ID return, where i went with AN-12 which is 16 iirc.

Another thought : your turbo could also be pulling oil from your breather system. Be sure you have some sort of chicanes between the block and turbo inlet. I am sure this also was one of my problems.

Good luck. I am really interestd to see how it ends up.

Great, great car and attention to detail.
 
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