Adjusting BOV fixed turbo from smoking?

[kinger]

I thought I would start a new post with some findings from my 'smoking turbo' issue that popped up recently. Some of you have been helpful in the other thread and I appreciate that!

I removed the intake and exhaust so basically just a turbo with nothing attached. As soon as I started it oil and air started pushing out the intake! Which I thought was weird as I was expecting it to suck air. I go up to the vortec BOV and it’s not releasing ANY air which I am used to seeing as it did that on my SC sled. I look at the adjustment and it seems like it’s WAY to tight meaning it won’t open without more vacuum. I referenced some old pictures on this site plus my SC vortec and felt confident I could let it out. The beauty of this BOV is it only takes 1.5” of vacuum to open but when you adjust the threaded allen bolt down it may take 5-8” to open.
I found some instructions online where you basically remove the bolt then screw in until you feel it contact a plate (held in tension with a spring) then 3 turns gives you about 4-5" of Hg before it opens, well on a car I think that is ok but on a little 1L at idle I think I want the 1.5" Hg so I backed it out to less then 1 turn after contact and air starts flowing. Back at the turbo it’s no longer pushing oil out into the intake (the actual intake that should only be sucking air) its sucking air AND the turbo stops smoking?!!!? (This could be cause the oil was hot by this time and maybe thicker)

Here is the valve you can see the rusty part of the threads are what I let out.

I have a new CHRA in the box ready to swap but I’ll cold start tomorrow and see if this fixed it.

I measured the oil return line and is a -6AN which seems small, if this fixed it for now I will upgrade to a -10 this summer. (Thanks for thinking of this Mbarry!)

 

[mbarryracing]

Kinger, my BOV's don't open at idle under vacuum. They require over 6 psi boost before they pop open when I chop the throttle.
Some base kits don't even come with BOV's, and the turbo's don't push oil like that. I don't think that is your issue.
The intended By-Pass Valve setup for a SC is little different than for a turbo...

I'm still hanging my gut feeling on the oil drain... -6 is way too small.

Here is a snip right from the Honeywell Garrett website.

Oil Drain
In general, the larger the oil drain, the better. However, a -10AN is typically sufficient for proper oil drainage, but try not to have an inner diameter smaller than the drain hole in the housing as this will likely cause the oil to back up in the center housing. Speaking of oil backing up in the center housing, a gravity feed needs to be just that! The oil outlet should follow the direction of gravity +/-35° when installed in the vehicle on level ground. If a gravity feed is not possible, a scavenge pump should be used to insure that oil flows freely away from the center housing.
Avoid:

• Undulations in the line or extended lengths parallel to the ground
• Draining into oil pan below oil level
• Dead heading into a component behind the oil pan
• Area behind the oil pan (windage tray window) where oil sling occurs from crankshaft

When installing your turbocharger, insure that the turbocharger axis of rotation is parallel to the level ground within +/- 15°. This means that the oil inlet/outlet should be within 15° of being perpendicular to level ground.

 

[rat4020]

I started out with a -6 return line and oil dripped out the down pipe right away then I changed it to a -8 and bored out all the fittings from the turbo return to the mag cover as big as possible that solved my oil problem

 

[mbarryracing]

My oil return with a scavenge pump is -8AN.

Think of the Turbo Center Section as let's say a large coffee can or small kids sand pail (CHRA doesn't hold very much volume)... Now pretend you have a short 2 foot length of garden hose plumbed to the bottom as a drain, then take the same size garden hose hooked to your house water spigot and turn it on filling the can with it...
Even though there is a restrictor on the oil feed that knocks down flow, it's still under pressure and has a pretty significant flow.

Same size hoses on feed and drain, but the pressurized water feed will still out-flow the gravity water drain and the can will eventually overflow... Unless you use a larger diameter drain hose to overcome the volume of feed...

 

[kinger]

mbarryracing - I think your right. Unfortunately I crash the sled so if I rebuild it I will be adding a larger drain. Thanks for all your help. Sled absolutely ripped!