OK following some discussions and no specific person having an idea of what is right (other than "keep the pick up pipe covered" ) Here is
the scenario.
A sump holds 4.5 litres of oil when at the full mark on the dipstick. It has a regular profile along it's length i.e. flat base front to rear
and same depth front to rear.
When it's running at say 3000RPM how much of the 4.5 litres of oil will be in the sump at any given time??
Just for a bit of fun really but it got me thinking what it would be.
[Edited on 28/8/08 by omega 24 v6]
i guess it depends on the total capacity of the oil galleys, and if you have an oil cooler etc, ie, anywhere else the oil will be other than in the sump
NO oil cooler etc only a std car engine. Ball park figure or guess please state when answering if it was a guess as it'd be interesting to see
how it comes out as guess versus intuitive decision.
Remember only for fun so no if it had this or if it had that.
Mines is a guess at 3 litres
[Edited on 28/8/08 by omega 24 v6]
ok, i'd guess it would be about half, 2.5 maybe?
I believe its quite a surprising amount, like 1/2 litre just gathered around the crank. That why race engines have scrappers a couple of thou away
from the webbing to knock this off and drain directly to the sump.
A simple analogy is a kitchen liquidiser, look how much gets thrown on the sides when making a milkshake with that tiny little blade! Okay a crank is
not designed to push liquid up in the same fashion but anthing that gets near it will be flung all over the engine internals and what heads for the
sump will just cause what is already in there to splash up.
3.9 lts
My guess would be less than two litres - I used to have a fairly knackered three litre Alfa which used to burn/leak oil so fast I gave up changing the
oil and just topped it up when the oil light came on too often - it too nearly 6 litres to fill it , and most top-up's were 5 litres
4 Ltrs, my sump holds dead on 4.5 ltrs. With the engine held at 3K revs pulled the dipstick and it had only gone down a very small amount, maybe not as much as .5 ltrs. I believe that if your oil filter has, (as it should), a non-return valve, then the various galleries already have oil in them, and with a windage tray, your not going to be getting a lot picked up on the crank. Cheers Ray
I reckon (guessing) there will be 3.5 litres in the sump.
The galleries are very small and oil lying in the head, around cams etc... will quickly drain back so I reckon 3.5 litres.
If you check the oil when cold and then just after switching off warm the difference on the dipstick should give a rough idea.
I checked SWMBO's Focus the other day just after she came in and it was off just below the low mark, while when cold it's on the high. It
had been standing a few minutes though.
Having chopped my Pinto sump probably more than I should I've always been a bit concerned there is not enough oil over the pick-up when it's
running.
quote:
Originally posted by blakep82
i guess it depends on the total capacity of the oil galleys, and if you have an oil cooler etc, ie, anywhere else the oil will be other than in the sump
Probs in the region of 4 litres, oil drains back through the engine pretty quickly, think about when you fill the engine, and when hot the oils a lot thinner. The filter has a non return so is always full, if the engines in good nick the galleries don't drain very quickly either, and on modern engines the windage tray stops the crank sloshing the oil all over.
From dry sump experience, when the oil is cold most of it was not in the tank (had an external sight gauge)! When the oil got to 50 C or so the tank slowly starts to fill up again. 80 C and it's all in the tank again.