Engine How does oil make its way into the front sump?

Sock_Monke

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Apr 1, 2025
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Like the title states, what carries oil to the front sump and where is it carried through?

After fixing my drain plug on the rear sump, I actually overfilled my oil by about a quart (left the oil filter on). To fix this I just popped the front drain plug off for a couple seconds.

This got me thinking, how long after I start the engine will it take for oil to flow back into the front sump of the oil pan?

Hopefully I’ll learn something here. Thanks!
 
The oil pan is open inside, when filling with oil the rear portion overflows into the front, no magic there, when changing the oil you take both drain plugs out to empty the pan.
Test on friday.....
Gotcha. So it’s purely a “spill over” pocket? Makes me wonder if I should’ve drained the oil from the rear sump, since I can’t see how any will get back into the front sump pocket now…
 
Don't over think it, it induces pain.
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As you see the 'hump' is to clear the k member and steering rack.
 
Years ago, at a parts show, someone had built a V8 engine with clear plastic panels in areas,, It was spun using an electric motor, It showed how much oil was pumped and splashed throughout while it was running..... Its an amazing amount of oil flying around inside an engine... Surprised me .......
 
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Years ago, at a parts show, someone had built a V8 engine with clear plastic panels in areas,, It was spun using an electric motor, It showed how much oil was pumped and splashed throughout while it was running..... Its an amazing amount of oil flying around inside and engine... Surprised me .......

You got a cam and crank and oil pump just splashing it all around like kids in a rain fall. :)




Add a little water and...



View: https://www.youtube.com/watch?v=pGL2rytTraA
 
Like the title states, what carries oil to the front sump and where is it carried through?

After fixing my drain plug on the rear sump, I actually overfilled my oil by about a quart (left the oil filter on). To fix this I just popped the front drain plug off for a couple seconds.

This got me thinking, how long after I start the engine will it take for oil to flow back into the front sump of the oil pan?

Hopefully I’ll learn something here. Thanks!
As far as I know the front sump is filled with oil from the the timing chain and most forward camshaft. And the pickup is in the rear sump . So it shouldn’t make much difference at all ? Under hard acceleration it would splash over to the rear sump where the oil pickup is located . At least in the performance oil pan . Mine doesn’t have a front drain . Please correct me if I’m in error ?
 
Don't overthink it.

When the engine runs, a good portion of it is up int he engine moving around. The pickup is in the rear sump. The oil drains down front to rear and if it falls into the front sump it will eventually overfill it and it will spill over the hump and flow down to to the rear sump.

Also, it's a Mustang. Chances are your car goosing the throttle a bit here and there so that helps relocate oil from the front sump to the rear. You can see it has a nice smooth transition to help the oil go up and over.

When you do an oil change, open both drains otherwise you won't fully drain oil from the front sump.
 
Don't overthink it.

When the engine runs, a good portion of it is up int he engine moving around. The pickup is in the rear sump. The oil drains down front to rear and if it falls into the front sump it will eventually overfill it and it will spill over the hump and flow down to to the rear sump.

Also, it's a Mustang. Chances are your car goosing the throttle a bit here and there so that helps relocate oil from the front sump to the rear. You can see it has a nice smooth transition to help the oil go up and over.

When you do an oil change, open both drains otherwise you won't fully drain oil from the front sump.
My only minor point is that its a 5 qt system and thats a qt not availible to the oil pickup for no good reason . Espçially on road courses , ford makes a factory performance pan to correct this oversight . For most it probably make a hoot . My pan was damaged and so a replaced it with the better one …?
 
My only minor point is that its a 5 qt system and thats a qt not availible to the oil pickup for no good reason .

So, your contention is that oil molecules being splashed around by a crank, cam, oil pump, and pushrods, all moving at 3000+ RPM, turning left, right, accelerating, and stopping, all stare at each other ruefully but stay in their own pools.


Ok :coff:


That's one scenario :stick: