Today I spent some time to investigate this issue.
Let me first say that I never ment fuel delivery or combustion issues would be a cause to the defect bearings I now have.
I have not yet been able to get in contact to flightmecanics, to briefly view into their respective service routins concerning oil-leak detection.
I have however spoken to different labs at Statoil, and one independent institution called`Cotax`, which is also a oil/research laboratory here i Norway. One of the labs at Statoil promised to e-mail me at a later time, but soon as possible.
I also planned to contact a instiution called `SINTEF`, but didn`t meet the right people today.
I`ll try again tomorrow.
Anyway, there was quite different answers...
The questions asked was:
1- What causes the fuel to change colour during some time?
2- Is the reaction a sign of degraded lubrication-ability?
3- Does turbine-oil react in any way as a cause of ultraviolet radiation?
4- Is anaerobic bacterial growth a vital factor for the lube-ability?
The first lab at Statoil answered like this:
1- Does it? I have never heard of turbine-oil used this way before.
The oil is made to lubricate gas turbines in a enclosed system, but
I`m surprised i does.
2- It might be, as the oil is not ment to be used like its in the first place.
3- Its the first time I`ve had that question, but it might have this sideeffect, but
is not that I`m aware, a inbuildt quality.
4- No, usually not in any oiltype. But bacterial growth is a danger to
filters, which can be blocked.
In my hunger to dig for proper answers, I`m waiting for the reply from the other Statoil lab in Stavanger. This was promised to me as a e-mail.
The third and last lab `Cotax`, answered like this:
1. If the fuel changes colour over a time of period, it`s certainly a sign of
changed capabilities.
The syntetic esther based oils are full of additives, which each and together
have given the oil its quality. The brown colour is most certain a sign of
oxydation to one or several components.
2. Degrading one or several components, means the oil no longer to comply
to the referring data-sheet. You can lo longer be sure of it`s quality.
I would suggest not to mix moore fuel that you expect to use, or find
another brand. ( I then said this seemed not to a issue to other brands, as I
seem to be the first whith this problem).
I would like to say you use a turbineoil which has a lower level of recistance
to hostile environments, but this can only be prooved in a test compared to
other brands. I can however take a acid-test to measure the acid-level in it.
This will for sure tell whats wrong. This will cost you at least NOK 1500, but
will give most of the answer you want to know.
The other brands seem to still keep high enough quality to your use of it,
but is never the less suffering of some degree of degrading.
It must be, as long it`s oxydated.
3. No, I would not think so. Have never heard if it.
4. No, it`s not. If the amount of anaerobic bacterial-growth is not larger than to
be absorbed by filters, this is not seemed as a big problem. The best
temperature for it, is about 60 deg Celcius. Temperatures below 50C is not
suitable for anaerobical growth, and would be cept to a minimum. This need
heat and water. Most turbine oils can contain 6-800 PPM (600-800??)of
water, whithout beeing detected by eye. ( I
don`t know what measure this means...)
I`m still not to the bottom in this issue as it rises moore question the moore I dig in it.... Anyway, a very comlex topic.
This last person at `Cotax`, seemed quite convincing over the phone, and was a person I felt was skilled at a high level.
I guess the theory about the ultraviolet is hanging by a thin thread, but it would be interesting to track this even furter. Normally, most plastics easily blocks any UV radiation, but i know there are some who don`t.
If I discover any other `news`conserning UV and other factors, I will hang it up here later.
So this was a days work as an electritian
I learned alot, and I`m changing to another brand like the rest of you guys, as it seems to be the remedy
Gudmund