Oil change - how much oil?

If you want to get really excited about this sort of stuff, you should see the process for monitoring large commercial jet engines.

Your typical Rolls Royce, General Electric, IAE engine will contain a myriad of bearings, these various bearings will utilise a pre-ordained cocktail of different metals in different bearings, in different areas of the engines.
These are monitored by scheduled removal and inspection of Magnetic Chip Detectors (known a MCDs).
These are analysed using specialised equipment which produce a coded read out (kind of a DNA print out of alloys etc). These are then compared against a known matrix which tells you what is wearing out in the engine and where, and whether or not it's within expected limits.
This is you early warning system for impending mechanical doom for an engine. Interestingly enough you're not always looking for quantity of material on the MCD, rather certain materials, which only come from the guts of a certain bearing, you see these and you raise a flag which quickly pulls that aircraft out of service to drop the engine.
Despite all this alloy design alchemy, you still (although pretty rarely) get the odd one going pop without warning......

Well Sid Squid

For a guy with over 7,000 posts recorded your egregious comments regarding filter debris, if discovered, is not what I'd have hoped for from a self professed pundit.

Extra knowledge is relevant and of course it's not the 'filter condition' but what it contains that may be studied to advantage if one so wishes.

The SV like the Rotax shares its gearbox oil with the engine. A magnetic tell tale plug helps monitor for ferrous debris, so it's nice to have the chance to be warned of gearbox problems before the engine packs it in. The filter will show other solids and non magnetics too. Again early knowledge could save one an inconvenient blow up.
Naturally it's more critical in a 'plane, see above what the Rolls Royce boys have to monitor.

mike hallam

All very technical if you have the facilities to do it.I have had two diesel engines sold as going trucks that had over 1 million kms on them and this is not untoward.I appreciate we are talking about smaller higher revving engines but one of our simple tests was to weigh the filters,both oil and air.Not exact science but this gave an inkling as to how dirty your oil was getting and air filter condition. Magnetic sump plugs also give you an indicator. If there was doubt sending a sample of oil for analysis.

The simple answer if one is paranoid about engine wear is to shorten the service intervals therby ensuring the engine has clean oil all the time.
Engines can still have mechanical failures for a multitude of reasons and it is not always down to oil.

[Sid Squid]

Originally Posted by mikehallam

Well Sid Squid

For a guy with over 7,000 posts recorded your egregious comments regarding filter debris, if discovered, is not what I'd have hoped for from a self professed pundit.

Extra knowledge is relevant and of course it's not the 'filter condition' but what it contains that may be studied to advantage if one so wishes.

The SV like the Rotax shares its gearbox oil with the engine. A magnetic tell tale plug helps monitor for ferrous debris, so it's nice to have the chance to be warned of gearbox problems before the engine packs it in. The filter will show other solids and non magnetics too. Again early knowledge could save one an inconvenient blow up.
Naturally it's more critical in a 'plane, see above what the Rolls Royce boys have to monitor.

mike hallam

Err.. What?

'Self professed pundit', 'egregious comments' - have I offended you? And if yes, then how? Or am I missing something else?

The relevant questioning was over filter condition, which is what I answered. As Yorkie Chris has eloquently explained, eyeballing the filter medium, (the suggestion made prior to your comments), will not inform as to filter condition. I'm well aware of the care aircraft industry takes of it's engines, and the lengths they go to to pre-empt failure. All of which you very well and correctly illustrated with your post, however to clarify this I merely pointed out that this will not inform of filter condition, and, at the risk of repeating myself, that was the question asked.

So, I'm still baffled as to your apparently somewhat piqued response.

[yorkie_chris]

Originally Posted by Sid Squid

So, I'm still baffled as to your apparently somewhat piqued response.

This should sum it up
http://www.youtube.com/watch?v=pb-0O...tailpage#t=20s

[punyXpress]

Who mentioned Geordieandrew?