FAO anyone with a GT series turbo without a metal bearing cage

[Fast Guy]

Let's give them the benefit of the doubt; cost over trying to generate more business from failures.

Nah, don't:lol:
I can remember back in the 90s an article discussing how items were/could be manufactured to deliberately fail early and there was some discussion about how (at the time) ecus could possibly be programmed to cause faults after a certain mileage for example.

 

[skiddusmarkus]

Mark, no-one is arguing that they shouldn't haveused a better material, but I am talking about prolonging what you have. People should be letting g their turbo cool down before turning their engines off anyway.

 

[MarkTurbo]

Even if you let it cool down the turbo will still be around 500 c, it would be interesting to know what sort of temperatures the bearings are getting to after you shut the engine off.

 

[red reading]

To fecking hot for plastic,no point sumising on it lads its just a stupid material to use,are we supposed to run electric oil pumps just to feed the turbo till its stone cold!!....lol

 

[MarkTurbo]

its just a stupid material to use

I came to that conclusion ages ago :lol: I was just trying to get the point across that if you shut a turbo down at 500 c that heat is going to bake whatever is around it, like litte bits of plastic ;-)

 

[skiddusmarkus]

And I'm trying to get across that if ypuve got a poor oil return limiting flow it might be more like 600degrees

 

[The Doc]

And I'm trying to get across that if ypuve got a poor oil return limiting flow it might be more like 600degrees

If you have a poor oil return you will have more oil trapped and that will help to cool rather than heed it! A good oil return will drain away what's there faster and you will have less thermal conductivity. Oil flow will not help cooling on shut down, the oil is the bearings lubricant, the water cooling of the core is to take heat away! And even with the engine ticking over you will still have high temps that effect plastic! Also as plastic is a petrochemical it naturally degrades in oil, so you will get a failure no matter what, at the end of the day do as you wish.....you can't polish a turd! They should have fitted bronze bearing cages, plastic cages used in a high temperature (950degrees and red hot on the turbine side) and high speed areas is a big no no.

 

[skiddusmarkus]

A good flow of oil is going to help carry heat away when running so the turbo would be at a lower temp. A few extra ml of oil cooking in the pipes isn't going to do much.

Totally agree about the use of inferior materials.

 

[MarkTurbo]

And I'm trying to get across that if ypuve got a poor oil return limiting flow it might be more like 600degrees

That'll never happen unless you've got a ridiculously crap oil return ;-)

Look at the size of the hole in the restrictor in this picture. Thats how much oil flows into the turbo and the oil return is a 16mm pipe which is never going to be a restriction to that amount of oil.

 

[The Doc]

Mark please post the other picture of the failed bearing cage, you can clearly see the differance that heat has made between it and the cooler compressor side in the picture above.

 

[MarkTurbo]

Mark please post the other picture of the failed bearing cage, you can clearly see the differance that heat has made between it and the cooler compressor side in the picture above.

Compressor side

There you go, nice little black pieces of brittle plastic from the exhaust side :lol:

 

[red reading]

And that piece of tim the remains are sitting on is supposed to be a heat shield between those bearings and the turbine running at 950degrees....laughable.

 

[gtirx2]

Is this sort of implying that all garrett bb gt/gtx turbos will come with steel cages by the end of the year? alone with some new hybrid balls lol

http://garrettbulletin.com/techcorner/garrett-by-honeywell-ball-bearing-turbochargers

 

[The Doc]

Yep that's a company that is trying to recoup lost sales as people have moved away to precision turbos etc that are already using ceramic bearings, a lot of that looks like waffle to me to try to steer round the issue .....special polyamide bearing cages.....fancy wording for shit plastic cages, they knew and could have stopped issues long ago but got many resales from it and now are losing buisness as people have wised up I suspect.

 

[gtirx2]

Yeah i agree,not really much mention of the new cages either really until right at the end, then there seems to be the well its not really are fault excuses feeling with mis-matching installations and extreme temperatures mentioned before hand lol.

All the focus is on the ceramic balls, which are most likely better but i suspect in the real world offer a negligible difference to performance anyway?

Also all the stuff about microscopic particals and wear is no dout true but tbh i cant really see that being to much of a concern in a well maintained car,the longevity and reliabilty is going to come from the new cage.

I wonder if second hand prices of the older plastic caged turbos will take a nose dive because of this?

 

[MarkTurbo]

Also, the temperature limit of the Polyamide (Engineering Plastic) retainers may be exceeded.

To help to combat this, we have also introduced some special treated steel cages to retain the balls. These have much higher tolerance of high temperatures (although oil temperature limits should still not be exceeded!), reduced wear rates and improved durability.

Anyone would think they've known about the bearing cage issues for years and chose to ignore until sales started dropping :lol: