Oil Sump Circulation Throughout Engine

[mbacfp]

Was curious how long it takes for a Sump of oil to completely circulate throughout an engine?

For example, 6.2 Hemi, 7 Quart Sump, No flow info on Oil Pump (just looking for estimation)
Calm highway driving at 70 mph, motor rpms between 1,000 – 1,200.

Would oil completely circulate completely every 5-7 minutes or so? Just curious.

 

[SteveSRT8]

Oh, a Hellcat supercharged mill! Much faster than that imo…

Even a normal oil pump will empty a sump in just a minute or two

 

[mbacfp]

Wow, that quick? Forgot Boost variable. Thanks Steve.

 

[bbhero]

I may well be wrong here... But I believe that it actually circulates 3-4 times a minute at 70-75 mph. Granted that's at 75 mph and my car turns 2500 rpm at that pace. I'd bet your application it would be 1-2 times per minute.

Zee0six would be a great help in this. That answer above was what he told me.

 

[mbacfp]

I'm way, way off. Thanks for the info.

 

[bbhero]

Don't worry. I was way off has well

 

[StevieC]

It's quite fast. I recall an oil filter I popped a tony hole in accidentally without knowing during installation. I started the vehicle. Within a minute the whole sump emptied onto the ground and the low oil light came on. I couldn't believe it.

 

[Charlie2015]

Completely circulate? Take your oil filter off, start up your car, and watch the entire contents escape in less than 20 seconds. The flow rate is much faster than you anticipate.

 

[zeng]

Originally Posted By: Charlie2015
Completely circulate? Take your oil filter off, start up your car, and watch the entire contents escape in less than 20 seconds. The flow rate is much faster than you anticipate.
Oil flow from pump outlets direct to oil filter , then onwards to oil galleries for main bearings, con-rod bearings (then to piston pin bush) and simultaneous flow to cam systems.
At 1500 engine rpm, oil circulations could be about 2 cycles per minute.

 

[ZeeOSix]

Originally Posted By: mbacfp
Was curious how long it takes for a Sump of oil to completely circulate throughout an engine?

For example, 6.2 Hemi, 7 Quart Sump, No flow info on Oil Pump (just looking for estimation)
Calm highway driving at 70 mph, motor rpms between 1,000 – 1,200.

Would oil completely circulate completely every 5-7 minutes or so? Just curious.


Positive displacement oil pump output volume is dependant on RPM.

At that low RPM I'd say the pump is only putting out around 1.5 GPM, so that's about 4.5 min to circulate 7 gallons. Near redline it would probably be a minute or less.

 

[FCD]

I've read at highway speeds the oil circulates inside the "average" engine's oil galleries at about 120mph.

 

[ZeeOSix]

Originally Posted By: FordCapriDriver
I've read at highway speeds the oil circulates inside the "average" engine's oil galleries at about 120mph.


I ran the numbers for a 1/2" dia gallery, and for a 2 GPM flow it is indeed close to 120 MPH.

 

[Duffyjr]

I guess I always just figured it was circulating pretty fast. The reason I assumed this was the flow rate the filters I use have.

Napa Gold 1040 and 1036 both say they have 7-9 gpm flow rate according the Napa site. But from what you guys are saying they aren't being pushed to their limits very often if ever they way I drive.

Another thing I found interesting is I've seen a few posts where they mention running a Wix/Gold in the summer and an XP in the winter for extra flow on start up.

 

[OilUzer]

Originally Posted By: ZeeOSix
Originally Posted By: FordCapriDriver
I've read at highway speeds the oil circulates inside the "average" engine's oil galleries at about 120mph.


I ran the numbers for a 1/2" dia gallery, and for a 2 GPM flow it is indeed close to 120 MPH.

Is it necessary to circulate that fast? Most oil filters seems to have small holes. is it very high pressure in the oil filter?

 

[Shannow]

I get a different answer...

8L/min...0.008cum per minute, 0.00013 cu m/sec.

1/2" oil gallery, (12mm), cross sectional area 0.000113square metres.


Flow/Area=1.15m/sec...time 3,600 seconds per hour...4.1km/h, closish to 3MPH

 

[OilUzer]

Originally Posted By: Shannow
I get a different answer...

8L/min...0.008cum per minute, 0.00013 cu m/sec.

1/2" oil gallery, (12mm), cross sectional area 0.000113square metres.


Flow/Area=1.15m/sec...time 3,600 seconds per hour...4.1km/h, closish to 3MPH



3 mph ... I feel better now!

I was wondering why not many more stuff including oil filters are not failing @120 mph!

 

[ZeeOSix]

... Need to check my calcs, think I flubbed the units.

 

[Shannow]

I think I missed 3 edits while trying to follow imperial units

1/2" IS .00136 square feet.

1 gallon .134 cubic feet (check, a cu foot is about 30+ litres)...two gallons .268 cu f.

.269 cuf, through .00136sq feet, in a minute … 200fpm

200fpm, about 2.3MPH..x1.61 = 3.7km/h

Makes sense, as the galleries fill in seconds, not milliseconds.

 

[ZeeOSix]

Originally Posted By: Shannow
I think I missed 3 edits while trying to follow imperial units

LoL, yeah I just bagged it - too hard trying to do it all on my phone.

I also got 2.23 MPH.

So on a side note, the flow is barely crawling inside the filter at 2 GPM while crusing mellow down the highway.

 

[Shannow]

All good I hate that loop on the easy stuff ...just to add to the discussion...here's the shear rates typical in engines in different parts...