Why do I need a -10AN oil drain for a DBB w/ 1MM oil restrictor ?

[PIONEER]

I see this is a touchy subject for a lot. some say use the double feed to drain formula some say use a tripple feed to drain formula. So If I have a DBB turbo with a 1MM hole for oil feed, why do I need a -10 or more drain if not a whole lot of oil is going in? I only ask b/c my -10An is touching the manifold, and I think I can get by using a -8 :biglaugh:

 

[IJ.]

Most DBB CHRA's have 2 x 1mm restrictors fitting just before the Oil enters the actual bearings.
(old dbb units had none so would flood badly)

Can't really see a reason why a -8 wouldn't work, I have mine plumbed -12 as that's the fitting that came on the Group A pan

 

[PIONEER]

So Russell and DEI don't state but I think it'll be about 1:49:13 before the inner's of that -10an melt from the heat of the manifold :icon_bigg

Seriously though, I think running about 1.5" T4 spacer, with a -8An drain should be more then enough here.

 

[IJ.]

Wow that's severely restricted as it is!

For that fittment I'd even consider a 45 facing out to a VDO scavenge pump then dump it back in to the drain.

 

[jdub]

Motor out of the car?
If so, another option would be to weld a -10 fitting to the pan.

 

[Facime]

yeah, thats ugly. Any room to clock the center section a little starboard and use a longer hose? I also found a 130 degree fitting off the turbo helps make that transition to the block a little smoother.

 

[PIONEER]

I played out the options in my head. If I go 45 out, then I'll have to come 90 back. The ideal setup would be to go Higher on the turbo thus extending the drain hose.

Jdub, The Pan also an option on the list, The engine is on the stand so I have some room to play around.

 

[IJ.]

45 out to a pump then the 90 back in doesn't matter at all

 

[jdub]

You need to get the line off the manifold runner in any case

 

[PIONEER]

45 out to a pump then the 90 back in doesn't matter at all

Effective solution. What brand are you running?

 

[IJ.]

VDO make a small pump much like a fuel pump that will do the job, you can mount it anywhere below the Turbo CHRA height then it can return to the stock port.

It has a -10 inlet from memory but with a 45 degree sweep off the bottom of the turbo it should all fit in and miss the runner..