View Full Version : Turbo Oil line fitting sizes. Block and turbo.

October 21st, 2005, 04:05 PM
Hey again guys,

I am getting the small stuff together for this months turbo kit....Already got the turbo, manifold....and some other stuff :)

But I need to know, what is the fitting ( bolt thread pitch size) for the oil sending line for the block?

Here is the pic:



its part number # 15407A

its the bolt that threads into the block...I need to know its size. The return line is already taken care of....I think...LOL

But for that matter...just in case, what is the thread pitch and size of the return line female end on the block?

What are you guys using on your aftermarket turbo set ups?

thanks so much,


October 21st, 2005, 04:08 PM
could this be it guys? :icon_conf



October 21st, 2005, 04:36 PM
what about the return? theres no threads there it uses a two bolt flange, unless i am misunderstanding your question.

M12x1.25 for the feed.

October 21st, 2005, 04:40 PM
The return is taken care of.....but thanks for that anyways lagged!

What is the oil sending line's bolt thread pitch size? Thats what I need to know so I can make me a SS braided line with earls fittings...

October 21st, 2005, 05:32 PM
1/8 bspt

Earls only do 1/8npt and while they're close in size/pitch there's enough of a difference that it will leak
(1 TPI and a different taper angle)

October 21st, 2005, 05:44 PM

I will go to my local piping/tubing company ( patco ) and have them order me some ( I guess not earls?).

IJ, this is for the oil feed line coming OUT of the block correct?

thanks IJ!


PS: I told you I dont play around...I am going to see on the RIGHT set up what exactly this stock rebuilt bottem end ( 17K miles on her) can handle....also playing with the idea of water/alcohol injection like Grand Lord is on Supra Forums....
That should help cool the pistons down.

My boost controller has a Hi/Low ( hi is basically scramble boost) setting...and yes its FULLY electrical......basically one of the best you can get!....so i can somehow hook up the water injection to the HI boost setting only! hehehehe

October 21st, 2005, 06:43 PM
I use an NPT Tap and tap the hole closest to the Big Oil fitting and use a Earls AN fitting for the mani supply to the turbo.

Meth/Water injection is a bit of a bandaid,

You need to remember it can run out or go wrong and the end result is you lose a motor.

(K.I.S.S. theory works well here (Keep It Simple Stupid ;) )

http://members.optushome.com.au/ianj/header16bt.jpg (http://members.optushome.com.au/ianj/header16b.jpg)

October 21st, 2005, 06:54 PM
http://members.optushome.com.au/ianj/header16bt.jpg (http://members.optushome.com.au/ianj/header16b.jpg)

is that the oil high pressure feed line from the block to the turbo?

Hell, you cant even see the hole....LMAO :biglaugh:

October 21st, 2005, 07:18 PM
Yep that's it if you enlarge it you'll see it's an NA block so it has a plug in it.

I run an NPT Tap in there about 8mm deep and use the Earls fitting.

You can use the Earls into the stock hole but it may leak and you run the rish of splitting the boss it screws into.

October 21st, 2005, 07:42 PM
the GTE blocks have a different size fitting Ian.. from memory its M8/M10 strait not tapered

October 21st, 2005, 08:12 PM
Hmmm ok could have sworn the dead GTE block was 1/8 BSPT.
<correction> Allan was right there is a 10mm parallel tapped hole forward of the Filter Boss.

I was talking about the 1/8bspt hole to the rear of the boss per the pic.