I did see a slight reduction in wear metals after switching to camguard. Especially iron/hour dropped quite significantly which I believe indicates that camguard works as promised.
I’m mixing it with Phillips XC. Burning a quart every 13 hours in a IO360 (200hp)
Your contribution is welcome, Martin2 
Blackstone do ask what additives you use, and in the past they have commented that the calcium comes from that – a tracer which is deliberately added to check it.
I thought Intertek were formerly QinetiQ?
I should state immediately that I work for one of the companies mentioned in the thread and if Peter wants to delete this post I would understand.
So just some comments and thoughts.
Unlike the turbine engines where oil analysis is fairly routine usually every few hundred hours, and the wear metals can build up to generate a good trend we throw away our piston engine oils roughly every 50 hrs. Having said that, a piston engine generates metal from day one (as said by ”A_and_C”)
I would totally agree that a one off analysis is just about useless and tells you very little. However, even though we change the oil, generally every 50hrs, it is possible for a trend to build up. But you are looking at several samples to get this trend which for the usual light aircraft could be a couple of years.. In my experience different engines can have what look like high levels of an element but may be perfectly normal for a specific engine. (as “By9468840” said, don’t instantly take a high ppm number as a panic)
A terrible time to take an oil sample is when the engine hasn’t been run for a while, you just get a major spike of iron! –Yes, I have seen it!! Do look at the filter
Preferably don’t change companies, look at reputation, quality (a good quality system costs money), equipment (cost would make your eyes water) and history. If local go and visit them. There are other companies in Europe. Although obvious I would probably add never to remove an engine just because of an oil analysis; it is just one of the tools available. A word of caution/suggestion all laboratories provide a analysis service but none (as far as I know, and open to correction) have any approvals or qualifications to say an engine is good to go only that it looks ok or is within suggested limits. Most reports will have exclusions for liability!!
Any doubts talk to the manufacturer who will have the material spec for your model of engine or local repair shop – you know your engine better than anybody.
Regarding Camguard I suspect no analysis company can take it into account as it is never put on the paperwork?
I’m not sure QinetiQ still do analysis? Intertek?
For me the only thing that matters are the trends and universal averages. I don’t care much about actual numbers. Once you establish a trend, it becomes your personal benchmark for your specific flying/oil changes/maintenence pattern.
I keep detailed records of metal/hour for a time period of at least 10 oil samples. If you keep records per hour than it doesn’t matter when you sample the oil. If I have then a sudden 10x increase in nickel I surely will start checking my data logs and boroscope cylinders before I do my next flight.
I use Blackstone too and have done for a few years, but I still find that an engine (I am on my second one now) can produce metals which are out of line with the average for that engine type.
I don’t know why this is; it could be caused by one specific component being at one end of the tolerance band and thus rubbing more, or rubbing less…
The main metals (the ones which produce lots of ppm) do tend to be comparable between engines of the same type if they are running regularly but a lot of engines are not running regularly. I also wonder whether Blackstone’s overall averages take into account the use of Camguard which (see the Camguard thread(s)) reduce the wear of the soft metals considerably.
I very much agree about trends. As I wrote previously, it is like PSA testing If you have been at 5 for 10 years and suddenly it goes to 10, you re-test and if same you go for an MRI. A brain dead GP might send you for a trans rectal biopsy. If an engine suddenly makes say 2x more metal you shorten the oil change intervals and thus test more often, and since the oil filter gets cut open each time you will pick up any serious problems sooner.
Send it to blackstone land in the US. Not worth doing it in Europe. The biggest advantage of Blackstone is that they provide comparison to thousands of similar airplanes they have in their database and an actual human analysis your results. No other company in Europe has such data and experience. Once you decide on the company to use, stick to it. Trends matter more than actual one off results.
It is true that not many people would open up an engine purely on the basis of oil analysis data, but the data can draw attention to some process which is on its way to do serious damage, so it may lead to a decision to overhaul an engine at say 1800hrs rather than try to take it to or past TBO. The additional cost in the hourly engine fund, via doing the OH earlier, is a few € per hour which is negligible when the extra risk is taken into account. To an aircraft owner who flies a lot, it is worth it for the peace of mind.
One good article is mentioned here.
Another case is here (you need to ignore the sarcasm by one poster).
As the time between flights goes up it is my opinion the usefulness of oil analysis goes down.
That’s probably true because a rarely run engine will be putting a lot more muck into the oil… or putting it another way, other things (camshaft surface disintegration, perhaps) will likely bite you first.
146 Fixer
Undoubtedly engines make metal from day one but skilled analysis will tell if this is normal for the time of life of the engine and is a good tool for predicting failure of engines that are run on a very regular basis.
As the time between flights goes up it is my opinion the usefulness of oil analysis goes down.
I use Blackstones.
I sent them a sample on 20th December and I got the results on 4th January.
