braided lines for the turbos

[sunsetR33]

Hi all.

So one of my major issues at the moment is my rear turbo leaking oil on the exhaust (and the general area). I presumed it was the rock hard super old drain hose, which it was not. So now I am in the midst of removing the rear turbo to get access to the banjo bolt that goes into the turbo oil feed.
As one of the previous owners accidentally? tore off the OEM oil feed hardline that reaches behind the turbo, they ran braided lines directly to the turbo, presumably PTFE.
Now, regardless if the line has rubber or teflon inside, is it just generally a bad idea to do this? I imagine these lines get quite hot being between the engine, turbo core and exhaust manifold. I suppose it's not too far fetched to think the line may even have melted.

I'd love to hear your opinions on this as as the replacement OEM hardline piece is 130 per unit. And cutting open the currently mounted line to see inside will mean I just have to get a replacement either way. So far I am hoping maybe the bolt just loosened or (god forbid) they forgot one of the crush washers.

[GTSBoy]

1 hour ago, sunsetR33 said:

is it just generally a bad idea to do this?

No it's fine. Heat sleeve is a thing.

1 hour ago, sunsetR33 said:

I suppose it's not too far fetched to think the line may even have melted.

With oil running through it it is unlikely. Engine off heat soak can be a thing though.

1 hour ago, sunsetR33 said:

And cutting open the currently mounted line to see inside will mean I just have to get a replacement either way. So far I am hoping maybe the bolt just loosened or (god forbid) they forgot one of the crush washers.

There is no way that you have a leak through the hose. That has pressure behind it and any small hole will turn into a large one in very short order. It is so much more likely to be leaking from the connection.

[sunsetR33]

Thanks for the reply @GTSBoy

Haven't really thought of that yet, but you are right. If the hose was damaged it should be absolutely pissing by now.

I'll put some heat sleeve around it for good measure since I'm already removing the line anyway. 

Maybe I'll put on some of the stock hardlines if I ever fully remove the turbos again. Maybe when T51R modding the compressor housings? Might be a fun mod on GT28s for that "fake single turbo" effect.

[Kinkstaah]

Take this with a pinch of salt, it's from someone (me) who got annoyed with turbos entirely.

I hated aftermarket lines. If I had the option to use hardlines with whatever turbo I had - I would use them, 10/10, 100% of the time. The only reason people go larger, heat resistent, shielded lines etc is because they have to.

And yes they don't last forever. Even if you spend big bucks on all the best heat shielding money can buy, with the best heat resistant, fuel resistant, oil resistant, radiation resistant hose, they get stiff and break down and just don't last the way a metal pipe will.

[The Bogan]

1 hour ago, Kinkstaah said:

Take this with a pinch of salt, it's from someone (me) who got annoyed with turbos entirely.

I hated aftermarket lines. If I had the option to use hardlines with whatever turbo I had - I would use them, 10/10, 100% of the time. The only reason people go larger, heat resistent, shielded lines etc is because they have to.

And yes they don't last forever. Even if you spend big bucks on all the best heat shielding money can buy, with the best heat resistant, fuel resistant, oil resistant, radiation resistant hose, they get stiff and break down and just don't last the way a metal pipe will.

Would something like this be an option 

https://processhose.com/products/configurable-metal-hoses/1-2-in-t316-stainless-steel-annular-corrugated-configurable-flexible-metal-hose-assembly-with-ends-t304-single-braid-masterflex-af5550.html

I'm looking at this for replacing the OEM EGR when installing a aftermarket intake plenum 

[GTSBoy]

1 hour ago, The Bogan said:

Would something like this be an option 

https://processhose.com/products/configurable-metal-hoses/1-2-in-t316-stainless-steel-annular-corrugated-configurable-flexible-metal-hose-assembly-with-ends-t304-single-braid-masterflex-af5550.html

I'm looking at this for replacing the OEM EGR when installing a aftermarket intake plenum 

For your application, where you'll be at that 1/2" size or perhaps larger, yeah, excellent. Although not if you need a tight bending radius anywhere, because the corrugated stuff is not anywhere near as flexible as rubber/teflon cored stuff.

But for turbo oil lines? No. Too big. They just don't do the corro stuff down at the ~1/4" ID size that you'd want, and if they did the OD of it would probably be a bit too fat for fitting it into the tight spaces available.

I use hoses like that all the time for fuel gases (LPG, NG) and liquid fuels (HFO, diesels, waste oils). When we did the London Olympic cauldron, with the 204 individual burners on it, we had miles of the stuff (although a lot of that was teflon core). A bunch of that crap is still cluttering up the workshop, more than 12 years later!

[sunsetR33]

23 hours ago, Kinkstaah said:

If I had the option to use hardlines with whatever turbo I had - I would use them, 10/10, 100% of the time.

I don't have the OEM oil feed lines though and the turbo-wraparound line is torn, only has water. My plan is to get replacements for these and just connect a braided line to there. And make sure it's leak free.

22 hours ago, The Bogan said:

Would something like this be an option 

https://processhose.com/products/configurable-metal-hoses/1-2-in-t316-stainless-steel-annular-corrugated-configurable-flexible-metal-hose-assembly-with-ends-t304-single-braid-masterflex-af5550.html

I'm looking at this for replacing the OEM EGR when installing a aftermarket intake plenum 

Hoses like these are also sometimes used to connect external wastegates, so for an EGR I think you're good using them.

[GTSBoy]

23 hours ago, Kinkstaah said:

If I had the option to use hardlines with whatever turbo I had - I would use them, 10/10, 100% of the time.

 

10 minutes ago, sunsetR33 said:

My plan is to get replacements for these and just connect a braided line to there

For what I gather is a Sunday/summer car....braided is fine. You're not going to be left without a vehicle and you have plenty of time for inspection/maintenance.

12 minutes ago, sunsetR33 said:

Hoses like these are also sometimes used to connect external wastegates

Oof. I wouldn't use them that way. They can probably handle the temperature** but the internal corrugations means that their flow characteristics are a bit shit. Lots of extra friction and pressure loss. Makes them flow like the next pipe size down.

** They are stainless, and the stainless can usually be at least something like 304L, which is pretty good at higher temperatures (unlike 316L, which I would use for a wrt/corrosive environment, but not a particularly hot environment). But the welding needs to be top notch. And even then, because you usually need at least one cone-seat end on them (because you can twist the hose and do up both ends at the same time unless one of them is a union) they can be prone to coming loose with heat cycles.