I have a built 383 twin turbo and i have a few concerns. I burn about a qaurt if oil every 500 miles. My oil turns black quick and i know the the tubros can cause that but i also know if im not venting the vapors correctly then that can cause that as well. My car has 2000 miles blows no blue smoke at all from idle to full boost at 6000 rpms. It leaks a little from the back of the valve covers. My catch can set up is both valve covers vent to one pretty small vented catch can and i have an lt1 style throttle body with the port on the side that would be used with a stock pcv setup plugged. I never have any oil in my catch can. Ive heard this is very critical to have this plumbed correctly and can cause oil consumption. Im sure i burn a small amount of oil from the nature of turbo cars but it cant all be from that cause if it was just the rings it would be very visible going down the road. I just wanted to see if anyone had any insight on this and what would be a better way to do this. Thanks

 

First, I would like to say that set up looks real good. I like it! Now as far your oil consumption is concerned, you should have at least one breather for fresh air to enter the crack case to help remove the gases that accumulate. Look at the way factory circulates positive crank case pressure, it has a fresh air source coming from throttle body to the valve cover and the other valve cover has the PCV which works during part throttle cruising (high vacuum periods).

In your case with being twin turbo, your fresh air source should come from one or both of filtered area side(s) of compressor housing to the valve covers. That should also have a catch can. I used a brake booster check valve and gorilla glued it to a PCV from the valve cover to the intake manifold somewhere after the throttle body to prevent boost leaks. It needs to be a vacuum source, the one on the side of the throttle body is not a vacuum source. You should also have a catch can on the PCV side. I 'll post up a pic of my set up later today.

Are your oil seal on the turbo leaking because of high Crank case pressures?

 

Haha thanks im have put a lot of time into her! Thanks for replying i appreciate it. I understand what your saying but im having a hard time picturing it. Some pictures or a drawling of it would be great! Thanks. Heres some closer pics

 

Pertaining to the oil seal leak not that i am aware of . I had my air filters off not too long ago and there wasnt any oil in the filters or the compressor housing.

 

If your can is empty and your dipstick is not getting pushed out, then you are OK on the crankcase pressure.
As far as where the oil is going? IDK

 

I agree. No oil in can nor blowing out dipstick, likely have ok crank case pressure. Rings may not seal during normal driving as much but fine under boost? Losing a quart every 500 miles is a good bit. Compression test all cylinders?

 

About 2 years ago i cracked all my ringlands on 7 out 8 pistons and had so much blow by when i hit boost the biggest cloud of blue smoke would come out and it had so much crank case pressure that it blew my filter off my catch can. My dip stick never moved so if it never moved when 7 pistons rings lands were cracked i dont think it would move ever . I did amd it was 220 - 230 across the board. If it were my rings i think i would notice it out the exhaust for sure

 

Hmm oil consumption is or can be a mystery lol becareful tho, you check the filter and pan for contaminants? My buddy lost a few quarts in a short time and turned out there was a bad lifter that wiped out the cam and eventually ruined the rod and main bearings. It ate some oil there and car never really skipped a beat. It was weird

 

I know this is getting annoying haha. I just had the intake off cause an engine builder had said to try replacing the intake manifold gaskets cause that can cause large oil consumption. All the lifters and pushrods looked good from there. The intake manifold gasket didnt make a difference. Its not like this all of a sudden started its been like this since i built the engine thats why i dont think something went bad or broke cause its been like this. When i was doing the intake gaskets i did notice some heavy build up on back side of the intake valves and there was a thin film of oil in the intake plenum.

 

Valve guides ok?

 

Also if you pull the valve covers check that your rocker studs are sealed if they protrude into the intake port. I had one leaking that wasn't blowing smoke but I was losing a good amount of oil. Took awhile to figure it out.

 

Im not sure about the valve guides is there any easy way to check them? The rocker studs are an interesting idea. I have race right brodix heads idk if they protruding or not ill call brodix today and see. I dont think they do but ill make sure.

 

I talked to brodix and they said the rocker studs do protrude into the intake so should this be a possibility? Thanks for everyones input!

 

Back to the catch can setup, should i still run it a different way?