Bubbles in oil right after engine turned off

[tallpaul]

Get a Super Tenere. The oil sight glass is for decorative purposes only.

[RederOR]

Oil has specific additives ant-foam additives, although they are more about preventing the foam staying for any length of time as you can't stop the creation in the first place since it's due to mechanical agitation.

This (above) The oil contains anti foam additives - some oils have more some less. The oil poured into brand new engine by Suzuki was bubbling like crazy comparing to Putoline (semi) I have now. Next oil I will will be some full synth as they usually are even richer in additives. Generally you won't avoid bubble/foam due to revs.

[bonne]

But when we are now talking overfilling... how much overfilling can be done without harming the engine?

I recently read that on racetracks, it is common to overfill the engine because it is supposed to lube the engine better. Don't know if this is true? But how much overfill is OK before engineer takes damage? 500 ml? 1000 ml? 2000 ml?

[kwackboy]

Over filling by a small amount up to maybe 150ml shouldn't cause any issues, in fact, I've seen many engines over filled by at least 1500ml that were running perfectly well.

Over filling of oil, in some cases can cause excess internal pressure which would need to escape from the weakest points. These being, seals and cam cover gasket, the latter being most common and worst case scenario would be a complete engine lock that can destroy many internal parts.   

[Mr Nick]

I don't think you can get a single answer as it depends on the design of the engine and sump. What you don't want is the bottom of the connecting rods hitting the oil, and the gap from normal oil level to the rod caps isn't a standard value.

[kwackboy]

Today an example of over filling....

This triumph 900 scrambler takes around 3.7 litres of oil, I drained out nearly 6 litres .. 

The airbox and airfilter was full of oil however, the bike was running fine .. 

[Rixington43]

Did they do an oil change but forget to drain the old stuff first perhaps ;)

[kwackboy]

No ... It was being filled on the side stand and scramblers lean over quite far 

[Rixington43]

Ah, that old classic 

[Dark-Strom]

At least the air filter won't corrode

[Mr Nick]

Not a problem if you have a Guzzi SP3: the filler & dipstick are on the left...

[Rixington43]

A different and considerably bigger problem if you set the level for that with it on the side stand though ;)

[Mr Nick]

They take that into account as the left cylinder pretty much blocks access unless you have it on the centrestand. Designed that way intentionally obviously...

[Dark-Strom]

First thing that came to mind for "bubbles in oil":~