Oil change - how much oil?

FWIW. FILTERS Inspection

The Rotax flat four cylinder light aircraft engine is only 1.2 litres and cruises all day at 5,000 rpm. Every filter change (annually or 100 hours) requires the filter element case is carefully sliced open & the filter paper unfolded to inspect for metal debris, on a clean paper towel.

So inspecting the filter does make sense, though not mandated by Suzuki.

mike hallam.

[Sid Squid]

Originally Posted by mikehallam

So inspecting the filter does make sense, though not mandated by Suzuki.

That's not relevant to this discussion, in the case of the aircraft engine inspecting the filter is done in order to ascertain what bits of engine are wearing and ending up in the filter, in doing so you are assessing engine condition, not filter condition.

[yorkie_chris]

Originally Posted by mikehallam

FWIW. FILTERS Inspection

The Rotax flat four cylinder light aircraft engine is only 1.2 litres and cruises all day at 5,000 rpm. Every filter change (annually or 100 hours) requires the filter element case is carefully sliced open & the filter paper unfolded to inspect for metal debris, on a clean paper towel.

So inspecting the filter does make sense, though not mandated by Suzuki.

mike hallam.

How many plates does the wet clutch on a rota... oh hang on...

The vast majority of contaminants on a bike filter are bits of clutch sh*t. A lot of these are submicron in size and you WILL NOT see them to look at until the filter is covered in sludge!

I did some testing of crap I pulled off a filter using a Nanosight LM10 as to particle sizes and stuff. You won't see them. For one very good reason that the crank strainer will stop anything >0.25mm or so!

In same way as you won't see big shards of metal until it's fatal for the engine. Like on an SV if the main bearings have been hammered into razor blades extruded out between the crank web and big ends.

Very very different application and problems.



For my money if you want to test filter efficacy and clogging based on mileage then what you want to test is filter pressure drop and flow rate (rpm, effectively), when the bypass opens on old and new filters. Should be fairly straightforward to test.

Originally Posted by Sid Squid

That's not relevant to this discussion, in the case of the aircraft engine inspecting the filter is done in order to ascertain what bits of engine are wearing and ending up in the filter, in doing so you are assessing engine condition, not filter condition.

But that is exactly the point i was making. If the filter is there to clean the engine oil, it stands to reason that the state of the filter can give some clues about both the condition of the filter and the engine.

My observation was not about comparing different filters. It was about comparing a new filter to an old one changed at interval. Seemed common sense to me.

[yorkie_chris]

Originally Posted by Runako

But that is exactly the point i was making. If the filter is there to clean the engine oil, it stands to reason that the state of the filter can give some clues about both the condition of the filter and the engine.

My observation was not about comparing different filters. It was about comparing a new filter to an old one changed at interval. Seemed common sense to me.

Have you seen a filter under a scanning electron microscope? If you had you would see the fact that the human eye has no chance of detecting the sort of crap that plugs up filters.

We are talking micron sized holes with micron sized bits of crap getting wedged in them. Not gert shards of iron or brass... if you are seeing those your engine is seriously stuffed!

Originally Posted by yorkie_chris

For my money if you want to test filter efficacy and clogging based on mileage then what you want to test is filter pressure drop and flow rate (rpm, effectively), when the bypass opens on old and new filters. Should be fairly straightforward to test.

Ok, so this is the kind of knowledge I don't have. But if you're not curious you'll never find stuff out. So then, from this explanation, is it possible to tell from the condition of a filter removed at interval what the condition of the engine is? For example a newly run in engine is surely in better condition than one that's done 50k. Can this show in the condition of the filter, in your opinion?

[yorkie_chris]

Nope.

What I would do in order of anal-ness...

-ride the f***ing thing, when it starts rattling buy a new engine off ebay and crack on. Mine is on 105k of being ridden like an absolute tw*t and is still going

-every oil change look inside hex-keyed plug under motor under oil pickup screen and check for bits (you'll find bits of knackered clutch, mostly)

-do regular compression tests (will tell you when rings need changing or something or other top-end problems)

-do regular oil-pressure tests (won't tell you anything until something breaks! It will be fine until the big ends are shredded and even then isn't obvious)


Basically by the time these engines start "making metal" and shedding bearing then damage has gone far enough that the crank is trashed. The gearboxes and other bearings are so good and so understressed you simply won't kill them.

Originally Posted by yorkie_chris

Nope.

Basically by the time these engines start "making metal" and shedding bearing then damage has gone far enough that the crank is trashed. The gearboxes and other bearings are so good and so understressed you simply won't kill them.

Thanks

[punyXpress]

Anyone used a magnetic sump plug?
Interesting to see how big the 'whiskers' grow on it.
Heavy quarrying plant used to have oil samples analysed between refills so it could be checked for metal debris, rock particles and unusual acids. Would tell you more than the contents of a used filter, ( or the entrails of a chicken)

[andrewsmith]

It's still done that way. Gennys are done that way

sent from a weapon of mass distraction