Turbos leaking questions

[Y-TRY]

My turbos have now began to leak and consume oil, giving my Pro-Touring car a "Spy Hunter/ James Bond" smoke screen effect.

I'm sure the cause for the leaking lies in insufficient draining, and I am in the process of addressing that. I asked the following question to PT&E and also Majestic Turbo (pretty reputible Texas turbo rebuilder) and got two distinctly different anwers. so I'll throw it to you guys..

Once the turbos begin leaking, will the seals need to be replaced, or will the laking cease when the drain issue is fixed?

PT&E says that, once the seals go, they will need to be replaced. Majestic says there are no real "seals" to fail but rather rings that create a seal. The leaking isn't caused by pressure over-powering the seals but rather the oil is simply overflowing. The idea is that my drains have failed, but not the rings, and they should be able to contain the oil as long as the drain is fixed.

I'm hoping Majestic is right, since rebuilding is kinda expensive through either of them, especially after only about 500 miles on them.

Also- When I was messing with the turbos this weekend a couple of the fasteners holding the housings on broke off in my hand. The hex-heads simply snapped in my fingers as-if they were made of SweetTarts. These were Grade 8, that came with the turbos. Very interesting, huh?

[ohcbird]

Call me crazy, but I'd rebuild them. M is right about most conventional turbo seals- they are 'hydrostatic' due to the shaft speeds on turbos & conventional seals would be cooked. I take it you're going to a bigger drain line that doesn't try to feed the pan 'against' the windage...correct? It should also be higher than any possible oil level.

What bolts broke off? Turbine housing, exhaust flange, etc??? Maybe somebody cooked the housings once before.

[Y-TRY]

I'm hoping to not have to re-build the turbos. They are brand-new Precisions. It sucks to spend $700+ per turbo and then another $400 each for rebuilding them after only a few times driving them.

The bolts that broke were the backing-plate bolts for the exhaust housings. They hold the housing to the cartridge. There is a little heat shield "cup" behind the wheel that is sealed to the cartridge when the bolts are tightened down. I'm crossing my fingers that replacing these bolts will cure the leaks. The oil actually leaks from the turbo (at rest) from between the "cup" and cartridge. Here's a pic of what I'm talking about.....

http://members.aol.com/ytry68/CamaroPics/turbowheels

See the "cups" behind the wheels? The one on the left is shiny, as the one on the right is sooty. It appears that oil is leaking from between the mating surfaces of these little tin cups and the cartridge. Usually, what keeps these tight together are these (broken) bolts and the housing. The housing presses the cup against the cartridge. Dig?

This is all my theory and I'll let you guys know how it goes. Another reason I'm leaning this way is because they just now started leaking. I'd think that if the drain was bad, it would have leaked immediately.

Either way, I will have the pan off anyway, so I'm putting -12 drains in before replacing it. Just to fix it once and for all. They feed above the oil level, but below the screen and scraper, at about the #2 main.

It'd be nice if some of the turbo gurus on here would chime in. I know you're out there. :D

[LIL QIK]

Majestic is telling it like it is.....they're just rings. What size are your lines now. The twelves that your planning on running should be pleanty large. I'm using -10's on mine. I'm draining into my oil pan but I've got the drain in the main cap area to try and avoid the oil slinging off the crank...not like I should have to worry about it.....the drain is also above the tray.. Hope this helps. But I seriously doubt that you need to rebuild them.

Just my two cents.

Hey.....what's the status of your car? I thought the last time I talked to you, you were thinking about yanking the blow through off and going injected.

[Y-TRY]

I sure hope you are right.

The draining is definately a problem. I was hoping to eek by with them..

When I was first building the set-up, with the engine still out of the car, I was told by an unnamed turbo place in San Antonio that I needed -6's at the pan. That's what I welded in for the drains. :mad: It wasn't until after the entire thing was in the car that I was corrected. So my current drains are 1/2" to -10 lines all the way down, but they reduce to -6 at the pan. I was hoping that the oil would be reduced by then and I could get away with that, but obviously not. I'm pulling the pan anyway to address a couple other things so I'm putting in -12 as overkill, and still planning on using the -10 lines. But if that doesn't work at least I won't have to pull the pan again to go to -12. As you know, it requires a bit of work to lift the engine enough to get the pan out.

It's just another lesson-learned in the process of building this car. The sooner I can get the car back up here to Dallas from my house in Austin, the faster I can get it done.

I'm keeping the blow-through for now and addressing some other issues, like this, before going EFI. The expense is pretty great for that swap. I'll be happier with some Fikse's and an intercooler first. Crazy priorities, I know.

I always keep Lateral-g posted first, so stay tuned.

[XcYZ]

Where are they drains in the pan? Adjacent to the caps?

[Y-TRY]

The drains are in the respective side of the pan, a few inches behind the engine mounts. I'd say about the 2nd or 3rd main-ish. The pan has a built-in windage screen and they drain below the screen so as not to interfere with the throws.

I'm rolling-around the idea to actually weld the drains in at an agnle this time, facing more forward, so that the oil aims towards the sump rather than just to the middle.

[Twin_Turbo]

-6 on the pan is definetely too small, a -10 line is on the small side also, I have -12 and it drains just fine. I have the bungs welded at an angle and the bungs are radiused inside for a smooth transition. My turbos have the same style seal and never leaked.
http://www.crossfire.homeip.net/twinnie/oilpanreturnline1.jpg

[Y-TRY]

That's what I'm thining, too, except that I think -10 should be fine, but I'll weld-in -12 just in case.

My drains are about the same place, maybe lower and slightly farther back.

[XcYZ]

Here's a shot of my pan with the bungs installed...

http://www.lateral-g.net/gulbranson/motor/oilpan.jpg

[Twin_Turbo]

not only are your weld bungs pretty small but those forged elbows don't help a lot either, the radiused full flow ones are much better, no wonder you have drainage problems. Kind of a shame that you have to redo it on that nice pan.

[XcYZ]

That's not Y-Try's pan, that's mine.

[Twin_Turbo]

Oh LOL..and it drains fine on yours? (not a big fan of forged elbows)

[XcYZ]

I'm curious about the oil supply lines that Nathan has on his setup; they look pretty big. The supply lines to my turbos, as spec'd by Banks, are .150" ID.

[Twin_Turbo]

Mine are in about the same range, -4AN to both turbos that's about .22 ID