Using 0W40 = more oil flow is false

[SenorFunkyPants]

Originally Posted by Smiley913

My main focus is trying to determine if 0w40 engine oil will result in a greater flow rate to engine components during operational temperature. I understand the operation of relief valve will determine how much oil is going to engine components (BMRLVR also touched upon this). Does anyone know what pressure the relief valve is set at or under what conditions the relieve valve or other mechanical device will divert flow from engine components?

Firstly I think it can be fairly assumed that the volume flow-controlled hinged-valve oil pump and the whole lubrication system has been optimized for a 10W60 oil and that the pressure control valve would not compromise the oil flow to the engine under any circumstances. IIRC the valve is set to 5 bar (but could be wrong).
I also understand that the oil pump feeds the low pressure VANOS and the timing chain tensioners so in normal operation the function (in part) of the pressure control valve is to ensure that the VANOS and timing chain tensioners receive oil at an optimal pressure.
What the effect of using a lighter weight oil would be in a lubrication system designed to run with a 10W60 oil is good question - hopefully it wouldn't have an unintended negative consequence on the VANOS and timing chain operation if it ran at a lower pressure when running at the preset volume flow rate.

[dparm]

Originally Posted by Smiley913

Thanks for all the information! It was very informative!

My main focus is trying to determine if 0w40 engine oil will result in a greater flow rate to engine components during operational temperature. I understand the operation of relief valve will determine how much oil is going to engine components (BMRLVR also touched upon this). Does anyone know what pressure the relief valve is set at or under what conditions the relieve valve or other mechanical device will divert flow from engine components?

Worth noting is that Mobil 1 0w40, for example, has HTHSV of 3.8. That is a measure of its viscosity at 150 C, which is a rough approximation of the oil's temperature in operation since the oil spikes that hot in areas like bearings.

TWS has an HTHSV of 5.3, making it roughly 30% thicker in operation.

So I would say yes, oil will get to nooks and crannies faster if you have a lower HTHS. There is also the notion of cold pumpability (CCS and MRV), but that's measured differently for a 0w40 versus 10w60 so it's tough to directly compare them.

[kawasaki00]

I will throw a few things out there. Because the oil pump is driven off the crankshaft it is impossible for it to control both flow and pressure independent of each other. The pump has a bypass circuit just like every other pump on the market. The bypass dumps back to the suction side of the pump. As rpm increase so does the pressure and that is dictated off the spring pack. The pressure is set from factory and does not change unless someone takes it apart and changes it manually. The pump can regulate flow in the same manner as new variable vane ac compressors. However the pressure still remains the same.
Because the pump is crank driven it always looks for a set pressure. When filling with a lighter oil the pressure will naturally drop. The pump can compensate for that and pick up the flow. Therefore, because the relief valve is always looking to a set pressure the flow is increased to maintain that pressure. Myself and others have logged the oil pressure while using lighter oils and the proof is in the gauge. At 210 on the oil the idle presure is maybe 3psi lower on average. The running pressure is the same from 0-40 to the 10-60. We have tested on many different engine the pressure difference of lighter oils. If the pump did not compensate, and that is what it is designed to do there would be lower running and much lower idle pressure.
If the pump was a normal pump like in a small chevy 350 then yes pressure would be down because of the thinner oil. We are lucky to have a oil pump like we do because it virtually guarantees the correct pressure.
So in conclusion because of the type of pump we have thinner oil will equal more flow due to continual pressure.

[SenorFunkyPants]

Is not the whole point of using a volume flow-controlled oil pump is that it regulates the oil output primarily by volume and secondarily by pressure? The volume flow control mechanism is built into the pump and dumps excess volume back into the system while the pressure control valve is downstream and dumps excess pressure back into the system.
It would make sense that in order to provide a fixed level of oil pressure to the Vanos that the oil pressure produced by the pump would almost always be above the pressure regulation valve setting (except perhaps at start up and tick over where the VANOS remains in the normal setting) in which case a thinner oil ought to give a higher flow rate. However the system will have been optimized for the flow rate produced when using the OEM oil so it is questionable what the benefit would be of having a higher flow rate (or even what the downsides might be).

[MFL]

Apparently you can be a chemical engineer and a retard at the same time. Congrats on your "High Functioning" status.

BMW used 10w60 strictly for accounting purposes/free maintenance purposes.

[Vic311]

Originally Posted by MFL

Apparently you can be a chemical engineer and a retard at the same time. Congrats on your "High Functioning" status.

BMW used 10w60 strictly for accounting purposes/free maintenance purposes.

What the hell does this even mean?

[dparm]

Originally Posted by Vic311

What the hell does this even mean?

He's implying that 10w60 was selected because it can tolerate longer change intervals, meaning fewer free oil changes for BMW to perform.

[SenorFunkyPants]

He had no need to be such a dick about it though. The OP made some interesting points.

[kawasaki00]

Originally Posted by SenorFunkyPants

He had no need to be such a dick about it though. The OP made some interesting points.

I agree but that is half the people on this forum. Grade "A"

[dparm]

Well, it's the Internet. My expectations are fairly low, so I'm rarely ticked off by people online.

[MFL]

Originally Posted by SenorFunkyPants

He had no need to be such a dick about it though. The OP made some interesting points.

This subject has been beat on like Rihanna and this self proclaimed chemical engineer decided to make a new thread and injecting more non-sense into kiddy pool already full of fucking non-sense.

Yep, you well researched people are wrong because I'm a chemical engineer! Game. Set. Match. DERRR!

[regular guy]

Originally Posted by SenorFunkyPants

Is not the whole point of using a volume flow-controlled oil pump is that it regulates the oil output primarily by volume and secondarily by pressure? The volume flow control mechanism is built into the pump and dumps excess volume back into the system while the pressure control valve is downstream and dumps excess pressure back into the system.
It would make sense that in order to provide a fixed level of oil pressure to the Vanos that the oil pressure produced by the pump would almost always be above the pressure regulation valve setting (except perhaps at start up and tick over where the VANOS remains in the normal setting) in which case a thinner oil ought to give a higher flow rate. However the system will have been optimized for the flow rate produced when using the OEM oil so it is questionable what the benefit would be of having a higher flow rate (or even what the downsides might be).

1) Can you provide any data to back up that statement?
2) Can you even explain what that statement means and how it relates to the VANOS?

What part of the VANOS cares about volume of oil going through it with respect to it's operation? Are you saying the VANOS regulates cam timing based on oil volume passing through it? If not, then the statement doesn't make any sense to me at all.

[Leonardo629]

What kind of car does OP drive?

And we never said anything about flowing more or less, but one does provide better lubrication especially when cold for the leaded bearings.

[SenorFunkyPants]

Originally Posted by regular guy

1) Can you provide any data to back up that statement?
2) Can you even explain what that statement means and how it relates to the VANOS?

What part of the VANOS cares about volume of oil going through it with respect to it's operation? Are you saying the VANOS regulates cam timing based on oil volume passing through it? If not, then the statement doesn't make any sense to me at all.

1/ Why would you not optimise the lubrication system design for the oil weight you intend to use? You want a set pressure for the VANOS and an optimum flow rate for the rest of the engine. If you lower the oil weight you still get (hopefully [1]) the oil pressure required by the VANOS but now an increased flow rate through the rest of the engine. If I have decided that 10x galls/min is the optimum max oil flow rate and it increases to 12x galls/min with a lighter weight oil...Is that a benefit? And if it is why wouldn't I choose 12x galls/min in the first place?
2/ It doesn't relate to the VANOS, as you note the VANOS doesn't care about the flow rate only pressure.

[1] unless the oil weight was too light.

[regular guy]

Originally Posted by SenorFunkyPants

1/ Why would you not optimise the lubrication system design for the oil weight you intend to use? You want a set pressure for the VANOS and an optimum flow rate for the rest of the engine. If you lower the oil weight you still get (hopefully [1]) the oil pressure required by the VANOS but now an increased flow rate through the rest of the engine. If I have decided that 10x galls/min is the optimum max oil flow rate and it increases to 12x galls/min with a lighter weight oil...Is that a benefit? And if it is why wouldn't I choose 12x galls/min in the first place?
2/ It doesn't relate to the VANOS, as you note the VANOS doesn't care about the flow rate only pressure.

[1] unless the oil weight was too light.

So we know that oil pressure will remain constant regardless of oil weight -- so you can take oil pressure out of your list of benefits to VANOS. The theory of the oil pump design proves that, but so does the empirical evidence (data logs) that backs it up. The light weight oil will be (arguably) better for the tight clearance of the bearings due to heat dissipation alone. The whole VANOS part of the oil weight discussion is a red herring to me.

I'm trying to grasp is the mere concept that the VANOS was "optimized" around 10W60 in the first place. That doesn't make any sense to me. So here's what I want to see for an explanation. Tell me how the VANOS operates with 10W60 -- I'm specifically looking for the role that the properties of 10W60 play in this function. Then replace it with 0W40 and tell me how the operation differs. A theoretical explanation is just fine as I know data doesn't exist for this.

[Amirsm3]

Originally Posted by regular guy

So we know that oil pressure will remain constant regardless of oil weight -- so you can take oil pressure out of your list of benefits to VANOS. The theory of the oil pump design proves that, but so does the empirical evidence (data logs) that backs it up. The light weight oil will be (arguably) better for the tight clearance of the bearings due to heat dissipation alone. The whole VANOS part of the oil weight discussion is a red herring to me.

I'm trying to grasp is the mere concept that the VANOS was "optimized" around 10W60 in the first place. That doesn't make any sense to me. So here's what I want to see for an explanation. Tell me how the VANOS operates with 10W60 -- I'm specifically looking for the role that the properties of 10W60 play in this function. Then replace it with 0W40 and tell me how the operation differs. A theoretical explanation is just fine as I know data doesn't exist for this.

Agreed, outside of some lubing properties, the VANOS system shouldn't be adversely affected by alternating between 10W-60 and )W-40. It runs off engine speed and throttle position - unlike VTEC and Nissan's VVEL, which incorporates oil pressure to switch between cam lobe profiles.

[BMRLVR]

Originally Posted by Amirsm3

Agreed, outside of some lubing properties, the VANOS system shouldn't be adversely affected by alternating between 10W-60 and )W-40. It runs off engine speed and throttle position - unlike VTEC and Nissan's VVEL, which incorporates oil pressure to switch between cam lobe profiles.

The VANOS phasers are driven by engine oil pressure.

[Petros]

Originally Posted by BMRLVR

The VANOS phasers are driven by engine oil pressure.

Which one?

[SenorFunkyPants]

Originally Posted by regular guy

I'm trying to grasp is the mere concept that the VANOS was "optimized" around 10W60 in the first place. That doesn't make any sense to me. So here's what I want to see for an explanation. Tell me how the VANOS operates with 10W60 -- I'm specifically looking for the role that the properties of 10W60 play in this function. Then replace it with 0W40 and tell me how the operation differs. A theoretical explanation is just fine as I know data doesn't exist for this.

I must be explaining myself poorly but I don't how else to rephrase it so that you can understand. Its the *lubrication system* that will be optimised around the oil weight....the point of mentioning the VANOS was to demonstrate the principle use of the pressure regulating valve.

[Amirsm3]

Originally Posted by BMRLVR

The VANOS phasers are driven by engine oil pressure.

Hmmm my bad. Must have overlooked that.

[swamp2]

Originally Posted by SenorFunkyPants

However the system will have been optimized for the flow rate produced when using the OEM oil so it is questionable what the benefit would be of having a higher flow rate (or even what the downsides might be).

I don't see the point of any skepticism of this claim by SFP. BMW clearly did some optimization work (arrived at a true global optimum across all or even many variables, probably not) in the oil system and they did so using the specified 10W-60 oil. The statement is almost a tautology...

Now that being said, the system is also inherently robust to changes in viscosity - it must be since oil viscosity changes with age, temperature, contamination, etc.

[regular guy]

Originally Posted by swamp2

I don't see the point of any skepticism of this claim by SFP. BMW clearly did some optimization work (arrived at a true global optimum across all or even many variables, probably not) in the oil system and they did so using the specified 10W-60 oil. The statement is almost a tautology...

Now that being said, the system is also inherently robust to changes in viscosity - it must be since oil viscosity changes with age, temperature, contamination, etc.

Well then I'll ask you the same question I asked him. Do you have any data to back that up? And can you describe what those optimizations might be (with data to prove it)? I hope so or else your other dings for people who lack evidence rings hollow.