What does the oil look like in yer engine at high revs?

[Steam]

Does the oil get all frothed and foamed up in the open spaces, or does it form a mist from all the whizzing spinning parts, or does it stay gluggy and mostly stuck to the parts, or what?
Does it get bubbly and aerated?

And how fast is it being pumped around by the oil pump? A couple of litres a minute, or faster? It would depend on the bike of course.

I was visualising a running engine the other day and I realised I don't really know how oil behaves when in extreme motion. Water I can imagine, we all know what that looks like when agitated. But not oil.

[007XX]

One completely uneducated guess...since it's being heated up by all the activity, doesn't it become more fluid? However, I would think that it probably would stay reasonably viscous...

maybe? Please teach me...

[ManDownUnder]

get an electric eggbeater and put it on high in a pan of warm or thin oil.... that's the stuff in your sump. Not frothy but agitated and splashing around a reasonable amount

That same oil is being squirted under pressure through jets and gallleries all around the motor (up to the head, onto bearings directly etc) so build that into the picture too.

Volume of oil being pumped around it a good question. Not sure although I'd expect it to be reasonably high (obviously related to engine speed).

[Ocean1]

Never seen a filum of it, would be interesting...

But yes it does get a tad less gluggy as it heats up.

As for what it looks like inside your crankcase? Most bikes are dry sump nowadays so there's usually no bloody great lake of oil lurking around down there for the crank to whip into a froth.

Safe to say there'd be a fair bit of mist though, and that's good, it's what lubricates the bottom of the cylinder.

[onearmedbandit]

Most bikes are dry sump nowadays so there's usually no bloody great lake of oil lurking around down there for the crank to whip into a froth.

Most bikes? Really?

[imdying]

Most bikes are dry sump nowadays so there's usually no bloody great lake of oil lurking around down there for the crank to whip into a froth.

Most bikes are what now?

[Ocean1]

I've told you a fekin million times don't exagerate!

Allrightalready, SOME bikes, sheesh...

And it depends on who you ask as to what "dry sump" means. Some don't have a seperate oil tank but still have a scavenge pump.

[007XX]

.... what's a sump?

Ok, never mind, you guys probably don't care much for the ABC

google is my friend....google is my friend...

[jrandom]

google is my friend....google is my friend...

Actually, Wikipedia is your friend.

[007XX]

Actually, Wikipedia is your friend.

Since I learnt that wikipedia is freely amended by members of the general public (aka: anyone that has an opinion ), I have decided to take its version of facts with a grain of salt...I like straight hard scientific facts, not the opinion of just any self professed know it all.

But thanks for the linky anyway

[imdying]

.... what's a sump?

Ok, never mind, you guys probably don't care much for the ABC

google is my friend....google is my friend...

It's where the oil lives in probably 99% of 4 stroke bike motors.

[007XX]

It's where the oil lives in probably 99% of 4 stroke bike motors.

Ok, so is the little window on the right handside of my bike part of that? The one where I can see the oil's level?

[Steam]

Ok, so is the little window on the right handside of my bike part of that? The one where I can see the oil's level?

Yep, that's the sump inside there. It's where the oil goes to sleep at night.

[Motu]

Find a dry sump bike and remove the filler cap - you should be able to see the oil return pipe.Give it a few revs and see what comes out.Bare in mind that the return pump is twice the capacity of the feed pump.....but the volume you see is what the feed pump supplies.

[The Stranger:Me]

Since I learnt that wikipedia is freely amended by members of the general public (aka: anyone that has an opinion ), I have decided to take its version of facts with a grain of salt...I like straight hard scientific facts, not the opinion of just any self professed know it all.

But thanks for the linky anyway

Actually Wikipedia is generally surprisingly accurate and self correcting.
Sure there are and always will be exceptions.
You really need to validate anything you get from the Internet anyway.