Oil sampling for Rotax

[rocket1172]

Has anyone done any scheduled oil sampling on Rotax engines and if so, where? And have the reports been useful? I don't have anything to sample yet, but will shortly, and am after any info please. Rod.

 

 

[Guest Maj Millard]

Oil sampling can be usefull if done over a long period of time, and throughout the engines life, so that a trend can be set. There are always some levels of metals in used oil, and a sudden increase can highlight an increase in wear, on a particular component.

 

Frankly I don't see it being widly used in the GA or small airline industry, but people operating helicopters or expensive jets may find it cost effective.................................................................................................Maj...

 

 

[facthunter]

Think it is cost effective with interstate transports where they try to get the maximum life out of the oils. It is also a good indicator of some cases of bearing failure. In aviation at the Rotax level cutting open the filter and looking for tell-tale particles should be enough as the oil changes would be fairly conservative regarding oil life. Getting the oil up to 85-90 degrees is necessary to ensure that water does not accumulate in the oil, otherwise change at six months or the hourly limit specified, whichever comes first, unless you have had to operate in dusty conditions etc.. Nev

 

 

[Guest ozzie]

To have this done via an aviation approved system would for the average rotax owner be cost prohibitive. An easier alternative and cheaper would be to have a talk to a fleet managment company that look after trucks and machinery mines ect. An even simpler system is to educate yourself in what is expected to be found in oil filters and oil samples. If you cut open your oil filter and spread the element out and view it under good white light and a high power magnifying glass you will find several different colours of metal, different metals have different colours. normal wear the particles are usually smooth edged and same sized. Excessive wear will normally show chunky rough edged of different sizes. Turbines usually benifit from spectro oil anaylis due to the small micron size particles and suspended carbon and fuel where predicting excessive wear trends needs to be picked up early.

 

 

[rocket1172]

Thanks guys for the input. It might be something I would do every 100 or 200 hours. I know in earthmoving, companys like Cat etc, do oil sampling with good results from trending samples over a long period. Cutting oil filters open was something we used to do on our Ag aircraft every 100, and although not much showed up, which was good, it would be nice to know something might be up. I might take the approach of cutting oil filters first, then oil sampling if suspect. Really wanted to know if this was something others practiced or not. Thanks again. Rod.

 

 

[Vev]

Hi Rod,

 

I haven't done any oil analysis on Rotax engines that I can recall but have done many many engines over the years.

 

As the Major said, trending is important and needs to be done consistently via the same method each time, it also requires good record keeping i.e. knowing when and how much oil top done etc.

 

You can get a very good feel for the lubricant condition in use as well as the particulates in situ .. this will allow you to start plotting and then predict failure over time... however it really takes a trained tribologist or condition monitoring engineer to interpret the results properly. I know some companies offer the interpretation with their oil analysis kits but I suggest these are about a 30/70 result in terms of usefulness and are more marketing than engineering.

 

Particle analysis will show up problems long before you see chunks in oil filters, although you need to maintain a high frequency sampling programme to do this with any accuracy.

 

I have used oil analysis on my own aircraft to look for precursors to identify potential problems, although I wouldn't recommend you do this owing to the costs ... I'm fortunate to have access to an oil lab and the training to do my own. There are some basic particulate analysis you can do yourself using filter-grams but you really need to know what you are looking at to be of any use.

 

I think the counsel given by Nev is spot on in terms of cost/risk outcomes ... Oil and filters are cheap, change them often and cut open the filter and take a look.

 

Hope this helps?

 

Cheers

 

Vev

 

 

[rocket1172]

Thanks Vev for your valuable input. It looks as though you could start your own business doing oil samples for us here on the site. I could be your first customer!! Anyway, thanks again. I look forward to a Tyabb visit once I get my purchase finalised. Nice airstrip indeed! Rod.

 

 

[Vev]

Thanks Vev for your valuable input. It looks as though you could start your own business doing oil samples for us here on the site. I could be your first customer!! Anyway, thanks again. I look forward to a Tyabb visit once I get my purchase finalised. Nice airstrip indeed! Rod.

Hi Rod,

 

Sorry about the delay.. I missed your response.

 

You are always welcome at Tyabb ... PM me when you are heading over and we can catch up.

 

May be when you get over we can have a chat about some simple tests you can do on your lubes to check condition as well as open up a filter or two and talk about the contents.

 

Cheers

 

Vev