overfilled is overhyped

[MolaKule]

Quote:
Despite possible variations in answers for those questions between one vehicle and another, is there a set "safe maximum" of overfill for all vehicles - possibly half a quart?

~ Triton


Each manufacturer sets the level of oil in the sump to cover many "dynamic" conditions such as acceleration, cornering, volume expansion of the fluid due to heating, hill climbing, valley drop, etc.

The problem with "overfilling" is the potential for air entrainment which reduces the lubricating ability of the fluid. The manf. wants to try and avoid as much "whipping" of the oil and air entrainment as possible.

One of the areas of whipping they try to avoid is obviously the crankshaft lobes hitting the oil in the sump under many dynamic conditions. Tappet action in the head also can also foam the oil.

Add to this piston squirters that cool the underside of the piston crowns, and you have many areas in the engine creating a lot of bubbles.

The best oil level is an indication on the dipstick of between add and full.

 

[turtlevette]

Originally Posted By: MolaKule
Originally Posted By: turtlevette
An extra quart provides extra heat sink. I don't think oil froths anymore. They put in additives to prevent that.


The siloxane polymers only makes the bubbles burst quicker, they do not prevent the oil from frothing due to overfilling.

Air does not lubricate.

The oil will finally come to an equilibrium temperature, whether it is 4 quarts or 10 quarts.


I'd like to see this. Are there any setups with a clear oil pan? I don't think the bottom couple of inches in the pan will be foam. Foaming will clear quickly. The majority of road racers overfill by a quart to lessen the chance the pickup will uncover. This puts your philosophy at odds with common practice.

Regarding temperature, you are thinking about it wrong, just like shannow. You need as much thermal reserve as possible. That reserve is the difference between lite cruise and wot. Around 100 deg f. One more quart is not the holy grail, but it will help a bit on wot blasts. The way performance cars are used.

There is some "smartness" going back and forth here BOTH ways. This forum is unique in that you cannot edit or delete overzealous statements. I could envision deleting the first sentence and last paragraph.

 

[MolaKule]

Originally Posted By: turtlevette
Originally Posted By: MolaKule
Originally Posted By: turtlevette
An extra quart provides extra heat sink. I don't think oil froths anymore. They put in additives to prevent that.


The siloxane polymers only makes the bubbles burst quicker, they do not prevent the oil from frothing due to overfilling.

Air does not lubricate.

The oil will finally come to an equilibrium temperature, whether it is 4 quarts or 10 quarts.




Regarding temperature, you are thinking about it wrong, just like shannow. You need as much thermal reserve as possible. That reserve is the difference between lite cruise and wot. Around 100 deg f. One more quart is not the holy grail, but it will help a bit on wot blasts. The way performance cars are used.

There is some "smartness" going back and forth here BOTH ways. This forum is unique in that you cannot edit or delete overzealous statements. I could envision deleting the first sentence and last paragraph.


Quote:
I'd like to see this. Are there any setups with a clear oil pan? I don't think the bottom couple of inches in the pan will be foam. Foaming will clear quickly. The majority of road racers overfill by a quart to lessen the chance the pickup will uncover. This puts your philosophy at odds with common practice.


With baffles or dry sumps, you don't need an extra quart, unless the engine is consuming an inordinate amount of oil during racing, and then an oil reservoir should be designed into the lubricating system.

Anytime the oil dumps into a wet sump, the turbulence of the oil picks up air and the bubbles go to the bottom and eventually rise due to something called "buoyancy." Basic fluid dynamics.

Quote:
Regarding temperature, you are thinking about it wrong, just like shannow. You need as much thermal reserve as possible. That reserve is the difference between lite cruise and wot. Around 100 deg f. One more quart is not the holy grail, but it will help a bit on wot blasts. The way performance cars are used.


I don't think you are viewing the complete thermodynamic picture. An extra quart of oil only means the oil takes a fractional longer amount of time to reach thermal equilibrium. You're right, an extra quart is NOT the holy grail.

Quote:
There is some "smartness" going back and forth here BOTH ways. This forum is unique in that you cannot edit or delete overzealous statements. I could envision deleting the first sentence and last paragraph.


When one does this, "..." it means there are other words or sentences before of after this, so when one uses "..." it does not infer anyone is ignoring anything. On the contrary, it means one is only addressing pertinent points in order to stay on topic and not go off on tangents.

As far as your "smartness" statement I have no idea as to what you are referring.

 

[turtlevette]

Originally Posted By: MolaKule

With baffles or dry sumps,
As far as your "smartness" statement I have no idea as to what you are referring.


How many here have baffles and dry sumps. Raise your hand if you have these.

If you have no idea, then don't worry about it.

 

[ccap41]

(hand raised)

Look up a modern car's oem oil pan. It isn't just a plan "bucket".

That is for a '13 Escape. Obviously not a dry sump though.

 

[TFB1]

Raises hand...

My 1969 428 Cobra Jet Torino has a windage tray to prevent the crank from whipping the oil to a froth at higher RPM(yes it was std production on these engines) ... Today MANY performance vehicles utilize this feature... If nothing else the crank whipping through the oil creates drag, keeping oil actually in pan maybe frees a HP or two as well...

With pan tucked under the vehicle and now days likely under a cover(no doubt creating poor air flow), I can't see that the amount of oil would make enough difference in temp to be meaningful... The extra oil is only going to transfer heat if there is a surface actually cooler than the oil... I can visualize extra oil actually running hotter as it closer to block... Could be the reason many vehicles, especially in HD applications utilize a water to oil cooler???

 

[Leonardo629]

My M3 oil pan

 

[Shannow]

Originally Posted By: turtlevette
Regarding temperature, you are thinking about it wrong, just like shannow. You need as much thermal reserve as possible. That reserve is the difference between lite cruise and wot. Around 100 deg f. One more quart is not the holy grail, but it will help a bit on wot blasts. The way performance cars are used.


How long does it take 5 quarts to rise in temperature on your proverbial blast ?

A minute ?

if so, then the extra quart makes it a minute 12 seconds....

10 seconds ?

if so then the extra quart makes it 12 seconds.

Neither of those are going to provide any material difference in engine life over a 3,000 mile OCI.

It's thermal storage capacity as you say, but it's once per acceleration event before it reaches equilibrium.

As I pointed out, the oiling system is shedding 35% more heat due to the temperature rise...continuously while the oil is at those temperatures.

If the system can't reach an equilibrium for whatever reason (cooling, some mechanical issue generating too much heat), an extra few seconds getting there is immaterial.

 

[Shannow]

Originally Posted By: turtlevette
Originally Posted By: MolaKule

With baffles or dry sumps,
As far as your "smartness" statement I have no idea as to what you are referring.


How many here have baffles and dry sumps. Raise your hand if you have these.

If you have no idea, then don't worry about it.

 

[MolaKule]

Originally Posted By: turtlevette
Originally Posted By: MolaKule

With baffles or dry sumps,
As far as your "smartness" statement I have no idea as to what you are referring.


How many here have baffles and dry sumps. Raise your hand if you have these.

If you have no idea, then don't worry about it.





My BIL's Racing S-10 has a dry sump and a 1 quart reservoir. Does that count?

 

[turtlevette]

Originally Posted By: Shannow


How long does it take 5 quarts to rise in temperature on your proverbial blast ?

A minute ?


an extra few seconds getting there is immaterial.


Im thinking more like 10 min. That's from my and many other's experience doing 20 minute sessions on various tracks. You're not wot all the time but maybe 25 to 50 %.

The difference between being a quart low and quart high is even more significant so you shouldn't wait until you are a quart low to add.

Mountain driving and towing would be similar.

Think of it as a temperature/energy dissipating surge tank.

 

[Doug Hillary]

Hi,

turtlevette - Please re-read this and try to understand it................especially about "air-entrainment"

Originally Posted By: MolaKule

Each manufacturer sets the level of oil in the sump to cover many "dynamic" conditions such as acceleration, cornering, volume expansion of the fluid due to heating, hill climbing, valley drop, etc.

The problem with "overfilling" is the potential for air entrainment which reduces the lubricating ability of the fluid. The manf. wants to try and avoid as much "whipping" of the oil and air entrainment as possible.

One of the areas of whipping they try to avoid is obviously the crankshaft lobes hitting the oil in the sump under many dynamic conditions. Tappet action in the head also can also foam the oil.

Add to this piston squirters that cool the underside of the piston crowns, and you have many areas in the engine creating a lot of bubbles.

The best oil level is an indication on the dipstick of between add and full.

 

[turtlevette]

Originally Posted By: Doug Hillary
Hi,

turtlevette - Please re-read this and try to understand it................especially about "air-entrainment"


Understood. Its a tradeoff. Aeration vs having enough to avoid uncovering the pickup.

I thought you're a big time hot rodder. You haven't seen all these guys overfilling for the road course?

 

[TFB1]

Originally Posted By: turtlevette
Originally Posted By: Doug Hillary
Hi,

turtlevette - Please re-read this and try to understand it................especially about "air-entrainment"


Understood. Its a tradeoff. Aeration vs having enough to avoid uncovering the pickup.

I thought you're a big time hot rodder. You haven't seen all these guys overfilling for the road course?


I think Doug is more into real race cars, over filling sounds like some of my SCCA freinds...

How'd this get to race cars that SHOULD have engineered system to take advantage of extra capacity... What about the the newer PASSENGER vehicles that under side is blocked buy a cover... You really think extra or a little low really makes a difference???

 

[turtlevette]

Originally Posted By: TFB1



I think Doug is more into real race cars, over filling sounds like some of my SCCA freinds...

How'd this get to race cars that SHOULD have engineered system to take advantage of extra capacity... What about the the newer PASSENGER vehicles that under side is blocked buy a cover... You really think extra or a little low really makes a difference???



Right. race cars with dry sumps have as much as 5 gallons of oil on board. That provides a significant thermal reserve.

The difference between 4 and 6 quarts on a 5 quart system is 50%.

 

[MolaKule]

Originally Posted By: TFB1
Originally Posted By: turtlevette
Originally Posted By: Doug Hillary
Hi,

turtlevette - Please re-read this and try to understand it................especially about "air-entrainment"


Understood. Its a tradeoff. Aeration vs having enough to avoid uncovering the pickup.

I thought you're a big time hot rodder. You haven't seen all these guys overfilling for the road course?


I think Doug is more into real race cars, over filling sounds like some of my SCCA freinds...

How'd this get to race cars that SHOULD have engineered system to take advantage of extra capacity... What about the the newer PASSENGER vehicles that under side is blocked buy a cover... You really think extra or a little low really makes a difference???



Merk, the OP, was talking about overfilling a 3.8L Buick, not a racing engine. Overfilling - a bad practice due to aeration of the oil.

Turtle, now you are discussing overfilling for racing - a bad practice due to aeration of the oil.

Just because some bad practices are used at the track by some that don't know any better doesn't mean they should be perpetuated.

 

[Shannow]

Originally Posted By: turtlevette
Originally Posted By: Shannow


How long does it take 5 quarts to rise in temperature on your proverbial blast ?

A minute ?


an extra few seconds getting there is immaterial.


Im thinking more like 10 min. That's from my and many other's experience doing 20 minute sessions on various tracks. You're not wot all the time but maybe 25 to 50 %.

The difference between being a quart low and quart high is even more significant so you shouldn't wait until you are a quart low to add.

Mountain driving and towing would be similar.

Think of it as a temperature/energy dissipating surge tank.


2KJ/KgK, your extra quart going up 50C is going to "store" an extra 90KJ of energy.

Over 10 minutes, 600 seconds, that's 150W of heat (3 low beams ??) that it's "accumulated"...at that temperature, the sump is still shedding 750W more than the baseline, and will continue to do so whole the "accumulator" is now full.

 

[MolaKule]

Originally Posted By: turtlevette
Originally Posted By: TFB1



I think Doug is more into real race cars, over filling sounds like some of my SCCA freinds...

How'd this get to race cars that SHOULD have engineered system to take advantage of extra capacity... What about the the newer PASSENGER vehicles that under side is blocked buy a cover... You really think extra or a little low really makes a difference???



Right. race cars with dry sumps have as much as 5 gallons of oil on board. That provides a significant thermal reserve.

The difference between 4 and 6 quarts on a 5 quart system is 50%.



You're telling me all 5 gallons are in the sump and being used at once and not in a reserve tank?

You guys in the NE sure do things differently.

 

[turtlevette]

Originally Posted By: MolaKule
You're telling me all 5 gallons are in the sump and being used at once and not in a reserve tank?

You guys in the NE sure do things differently.


No man. It's a dry sump. Then you have a 5 stage external belt driven oil pump that scavenges the oil from different spots in the engine. Lifer valley, oil pan etc. and puts that oil in what looks like a little beer keg. The oil pump also pulls a vacuum on the crankcase saving a little bit of hp. No crank windage.

Then the one stage runs from the bottom of the tank to the pressure input port on the engine.

 

[Doug Hillary]

Hi,

Originally Posted By: Merkava_4

I don't think the Buick engine is the only engine out there unaffected by the extra quart. I think there's plenty of other engines out there that would be unaffected too. Maybe even some of those fragile Hondas.

Back to the OP suggestions; he is correct some engines will be affected by overfilling with lubricant and others won't! Simple logic really!!

The question is surely; is it wise or not? Unless the dipstick is recalibrated after trial and testing you won't really know!

Follow the OEM's advice is always wise - the consequences can be dire - I have seen some of these on a number of occasions!!

It is a great pity that some BITOG Posters steal Topics and Posts and the incidence of aggression does nothing for the image of BITOG IMO