Slowly trying to narrow down this problem. I pulled the turbo system off and put standard headers on the engine. The engine is fresh and does not smoke until I chop the throttle closed and a vacuum is pulled on the intake port. I may have lightly ported into an oil passage in the intake port. The smoke is fairly light aka not much smoke but its there.

With the turbo on the engine it smoke furiously!

Any insight would be helpful.

This is a single cylinder 1L engine with 4 valve head.
Feel free to ask questions about info I may not have provided. I'm new to turbos.

 

Check your turbo drain line, make sure it isn't kinked. Most FI engines are set up with wide ring gaps and will smoke a little bit if they aren't at full chat.

 

Intake valve seals are a possibility.

 

As are exhaust valve guide seals

 

Thanks for the input. My valve seals are fresh but may pull the head and check everything out anyway.

The drain line is -8 and I have too much crank case pressure...it just wont flow into the engine, it backs up and starts smoking. So next I plumbed a "T" into the suction side of the oil pump, its a dry sump engine. The suction side pulls from the dry sump oil tank and turbo. That aint working either.
Im thinking about oil restriction on the -4 feed line at this point. The turbo is not ball bearing! which is a little scary.

Can I go down to like .060 restriction with a journal bear system. The engine holds 40psi oil pressure at idle.

 

So does it smoke without the turbo system on it?

 

Very light smoke when the throttle blade is closed. No smoke when throttling up. I'm addressing that part right now. Looks like I barely broke into an oil passage that runs parallel to the intake port.

But MASSIVE smoke with turbo system on!

 

-8 drain is too small. -10 is absolute minimum, -12 being better.

 

Point taken. Thanks!

 

Yeh what BMR said.

 

If it is race only, I would not be afraid to restrict the oil to the turbo. I had to do it to my GN because it had too much oil pressure. Its been several thousand miles with no issues.

 

Its race only. 30sec warmup and 3.5 second pass. So I think I'll go for the restriction. Would .060 be too small.

 

If there is a pinhole into a main oil passage you can remove the turbo oil feed line and it will still smoke the same way, high vacuum is sucking pressurized oil into your intake port . I would try to fix the known problem , I am and have been running an AN10 on my turbo without a dry sump system with no smoke . I am running a vent system that separates air and oil under boost and returns oil to the sump after I am off boost , I would suggest you try something like that to relieve your crank case pressure.

 

With the entire turbo system removed it was lightly smoking under intake vacuum. I have the oil passage problem addressed now. So I'll get the turbo back on and get back to the major smoking problem.

A vent system that separates air and oil under boost? I can quite picture what your saying. Could you elaborate?

 

On my tank I installed multiple baffle plates that I rotated 90 degrees from each other and stacked 8 of them to prevent oil being able to squirt up to the top. The way it is set up the baffles separate the oil from the air , the air exhausts through the baffles and out through a valve cover vent at the top . I have AN10 hoses to my valve covers and another one to my oil filler neck, all three go to AN fittings on the bottom of the tank . When I come off boost the oil drains back with gravity . The oil is still clean and I do not lose any. The tank must be mounted higher than your drain back for it to work. I am going to build a new one for my car pretty soon , if you would like I will send some pics to you.

 

Pics would be awesome. You can post them in this thread if that's ok with you. Or sent me a PM, whatever you want to do and thanks everybody for the help!