NA --> ECO Conversion + Turbo Rebuild Kit

[Fatmobile]

Oil in the input to the turbo is from blowby.
Oil coming from the turbo is also the blowby oil,
plus whatever the turbo is leaking.

Point is; it's hard to tell how much it's leaking when there was so much oil entering the turbo..

Congrats on the great find.

[the vegenator]

I'm fixin' to add the turbo components to my engine, but am feeling more and more weary of the pressures that turbos can put on these cars.

Any idea what kind of temps I'll be sending out the exhaust with this eco-turbo add-on? I'm adding a boost gauge, but the EGT gauge seems cost-prohibitive. I could potentially be talked into it, but keep that in mind that I'm not planning on racing it. The most I'll get out of it is maintaining (not gaining) speed up large hills or mountains.

Also, I have no idea how to test the wastegate on this unit. Once everything is in place, will the boost gauge indicate that the wastegate is doing its job?

[Fatmobile]

The boost guage should tell you if the waste gate is keeping the boost low enough.

[the vegenator]

thanks fat! makes things easier.

[the vegenator]

Turbo Diagnostics: An unfortunate tale

I had my engine/tranny hanging from the hoist ready to drop in, and the last thing I had to do was bleed oil through the turbo bearings. I did this by sucking oil from a container into the oil inlet, using a mityvac pump on the drain line of the turbo. I wasn't getting vacuum at all, but I could hear air flow out the compressor in/outlets. When I covered up both compressor turbine outlets with the palms of my hand, I finally got vacuum and was able to suck oil through, proving that some kind of seal was busted.

Now I know how to tell if the turbo bearings are properly sealed - just wish I had figured that out earlier.

And now I'm back to considering rebuilding the turbo myself. Or at least resealing it. If anyone has any Melett documentation or rebuild PDFs, I'd love to see them. Until then I'll study the aforementioned "Jake's KKK K24 Rebuild" to see if I'm up for the task.

[Una]

I don't know that I'd call that test conclusive. Yeah, it seems like a bad sign, but the seals aren't meant to seal that way. They're meant to have oil pressure pressing out on them, not air pressure on the outside pushing in on them. Oil is rarely ever sucked OUT of a turbo, and even if it were, the air coming IN through the seals wouldn't be letting oil out. What you really need to find out is if oil leaks out those seals or not.

[the vegenator]

Hmm, good info. I'm not sure if I was clear or not, but I wasn't trying to force air IN to the bearing area, but was just using the mityvac on the drain line to suck oil THROUGH the bearing area. Either way, I'll do some more tests and probably end up opening it up to take a better look at everything.

I should reiterate that the dang thing was soaked in oil when I pulled it - inside and out!

[vanbcguy]

The turbo oil seals aren't positive seals. They are definitely not airtight!!

Pressurized oil flows from the oil inlet around the turbo shaft, out the bearings and enters the oil drain part of the turbo. The drain portion of the turbo is at atmospheric pressure (it is not pressurized). The seals are meant to prevent oil spilling from the drain area out along the turbo shaft, but they are absolutely not designed nor expected to seal against pressure. Trying to come up with a positive seal on a shaft that spins upwards of 100,000 RPM, has one side varying from 200°F to 1200+°F in a few seconds and where the other side can be seeing temperatures from well below freezing during winter operation to several hundred °F under boost sounds like an engineer's nightmare!

Oil should only be leaking past the seals if the drain has been exposed to pressure / blockage, if the turbo was turned on its side or upside down when full of oil or if the seals are completely and utterly worn to nothing, but at that point the turbo bearings are likely shot too.

In other words, if you don't have excessive turbo shaft play, it's PROBABLY fine.

[Fatmobile]

Right, the seals are better at flinging the oil away than sealing.

High block pressure can cause oil to be forced past them.
Alot of blowby wil also enter the turbo from the intake,.. making the whole turbo oily inside.

I wouldn't give up on that turbo yet.