Oil feed fitting thread?

[RobDon]

Anyone know the oil feed thread size for Garrett turbos? Mine is this:

Hoping one side is -4AN. Could the other be 1/8"NPT (the side that screws into the turbo itself)?

 

[Backdraft]

- 4 fitting into the turbo.

 

[INA]

- 4 fitting into the turbo.

No
Depends on which CHRA is in question here.

If you took your 4-AN fitting and tried to screw it into the CHRA it would not go more than 2 threads without stopping.

 

[RobDon]

Looks like NPT to me. I asked ATP for info but they haven't replied. The GT2X is a Garrett turbo based on the GT2056 turbo. Oil feed inlet looks like this:

Doesn't matter too much, as long as the feed line is -4AN then that's what I really need to know.

 

[Backdraft]

Yes the feed line to the oil restrictor is -4, not into the turbo. I had a better look this morning

 

[RobDon]

That's great, thanks for the info all.

 

[Willie]

Rob, the top fitting is a -4 JIC or -4 AN to a 1/4" BSP.

By the look of the pictures of the turbo it looks like a 1/4" NPT.
I have a few fittings in the house you can try if you want to prove/disprove.

If the turbo is a 1/4" NPT you will need special high temperature thread SEALING compound.
We use either thread tape or SWAK but not too sure how this handles high temperatures as our still is all low temperature hydraulics.

 

[INA]

It isnt an NPT thread.
It is an NPS or BSP thread.If I recall a 7/16-24 or similar. If you looked at your restrictor you would see it is not tappered but yes 4-AN or 3-AN feed line is more than adequate.

 

[RobDon]

Cool, I only need to work with the feed line itself, so if both ends are -4AN then that's fine. I have extreme temp threadlock anyway, got it from 034, rated to 2100F.

http://www.034motorsport.com/product_info.php?cPath=84&products_id=609

 

[Backdraft]

It isnt an NPT thread.
It is an NPS or BSP thread.If I recall a 7/16-24 or similar. If you looked at your restrictor you would see it is not tappered but yes 4-AN or 3-AN feed line is more than adequate.

Correct. I actually measured the restrictor at .4375" which is 7/16 and looks like the thread is 24 which I have confirmed by doing some digging. The restrictor is shaped to seal against the turbo so there will be no leaks. BSPP is parrellel threads and BSPT is tapered which refers mainly to british standards and NPS is basicly the same thing but how the US call it.

 

[Willie]

Correct. I actually measured the restrictor at .4375" which is 7/16 and looks like the thread is 24 which I have confirmed by doing some digging. The restrictor is shaped to seal against the turbo so there will be no leaks. BSPP is parrellel threads and BSPT is tapered which refers mainly to british standards and NPS is basicly the same thing but how the US call it.

So if it's shaped to seal against the turbo you will need a BSPP threaded connection with either a copper washer or rubber o'ring, depending on the design of BSPP fitting you get.

The one for the copper washer is flush faced and the one for an o'ring is slightly recessed.

You thread lock is no good for a tapered thread, its thread sealant you need to fill in all the little inperfection in the threads.

 

[INA]

Correct. I actually measured the restrictor at .4375" which is 7/16 and looks like the thread is 24 which I have confirmed by doing some digging. The restrictor is shaped to seal against the turbo so there will be no leaks. BSPP is parrellel threads and BSPT is tapered which refers mainly to british standards and NPS is basicly the same thing but how the US call it.

I have no idea
I grew up on BSP & Metric threads.I only became familiar with NPT an AN fittings when I moved here.

You do not need a sealant as the restrictor bottoms out in the turbocharger CHRA. I have never had one leak on me as yet.

 

[Backdraft]

You do not need a sealant as the restrictor bottoms out in the turbocharger CHRA. I have never had one leak on me as yet.

Its just the same as how a brake pipe fits to the brake hose or an oil line onto an oil cooler. Seals metal to metal so no need for o-rings, washers or sealant. More likely to leak from the braided line on the -4 fitting.

 

[RobDon]

No worries guys, -4AN was the important part, I have the part I was waiting on, pics soon.