Author Topic: oil drain hole at base of vane carrier/CS (Read 4188 times)

DonGTI · « **on:** June 21, 2008, 10:57:28 pm »

Was reading through a topic here and there was reference to this drain hole, saying that some vnt turbos have it at the base of the vane carrier and that if such a turbo is clocked, it needs to be re-drilled at the new base.

some turbos have that problem whilst others do not... so in general what do i need to look out for to say which turbos are like that when they have been opened?

I bought a hybrid VNT15 with a 17 center section which the seller does not know what it came off... The 15's and 17's definitely have this hole but no idea about where it is or how to allign it ecc.

Can anyone help clarify this pls?

thanks
Daniel

jimfoo · « **Reply #1 on:** June 22, 2008, 06:01:20 am »

A lot of VNT's are hard to clock because of pins in the exhaust housing that extend into the vanes. However not all are like that. The bottom of the center section should always be within a certain percentage of straight down, I think 15 degrees. No matter what you do, you can't go past that and expect any kind of life from the turbo as oil will pool and coke up. I believe the post about drilling a hole is for a different turbo as I see nothing that would require it in a VNT unless yours was a rare one with a 360 degree thrust bearing. Your center section is from some kind of Nissan Diesel truck I believe. I forgot which one though.

DonGTI · « **Reply #2 on:** June 22, 2008, 06:34:12 am »

being its previous, previous owner, any idea if it has that oil hole in the right place for a VW AAZ application? I was planning to take it apart, mount a vnt 17 compressor wheel and housing and send it for balancing... but the guy i'm sending it off to said i have to check any such issues beforehand.

jimfoo · « **Reply #3 on:** June 22, 2008, 07:54:05 am »

I don't believe you will need to do anything. When you take it apart to mount the compressor housing, it should have a big open area in the thrust bearing at the bottom which you can see the oil drain through. If not, then you will probably need to drill a hole. I can't seem to find the post that mentioned drilling the hole, but I thought it had pictures.

DonGTI · « **Reply #4 on:** June 22, 2008, 08:20:18 am »

thanks

DonGTI · « **Reply #5 on:** June 22, 2008, 08:57:22 am »

so that has to match with a similar hole in the vane carrier or with the core or with both?

DonGTI · « **Reply #6 on:** June 22, 2008, 08:59:36 am »

p.s. 6 core screws? or did you rotate the core?

DonGTI · « **Reply #7 on:** June 22, 2008, 10:02:09 pm »

Here's a pic with the vane carrier in place, the hole looks like its at the bottom, does that mean its in the correct place?

(courtesy of Foxracer1)

jimfoo · « **Reply #8 on:** June 23, 2008, 04:47:05 am »

If that's what it is on yours, then yes, but none of my 3 have any kind of drain hole. One has a hole in a similar place for an alignment pin, but that's all. I think your chances of actually having such a hole are slim.

DonGTI · « **Reply #9 on:** June 23, 2008, 06:21:42 am »

If the drain hole we're refering to is the one inside the circle...

It matches with libbybapa's (below)

I've seen a couple of posts in this forum regarding clocking VNT's and it involves drilling holes in the core to accomodate the 3 vane carrier screws... so i think it is doable... but i shamefully admit that from Foxracer1's pics i can't make up which way of the center section is up because i have no idea re. orientation... we'll have to see when it gets here then...

Jim, apart from the VNT 17 on the Landey, what other set-ups are you running? or are the other 2 just spare turbos?

jimfoo · « **Reply #10 on:** June 23, 2008, 07:14:16 am »

I have a used VNT 15 I had bought first, and a VNT 25 that was toast I got from Andrew for parts.