HPL SAE 40 PCMO

[Japanese]

For certain his is also looking for maximum wear protection. If I was looking for a used car I'd like to find his because I know he protected it well.

Right, that is what I was about to say. I think the Honda Hohn is driving has an issue with a cam lobe that drives the water pump (if I remember correctly). That lobe doesn't get enough oil film/lubrication with lower viscosity oils and often fails. That's when talking about engine at operating temp.

However, as far as I've read, most of the engine wear happnes at cold starts because certain engine parts get oil a bit later and the oil is still cold. Also, higher viscosity (thicker) oils need more time to reach engine operating temp. because absorb heat slower than lower viscosity oils.

 

[kschachn]

However, as far as I read, most of the engine wear happnes at cold starts because certain engine parts get oil a bit later and the oil is still cold. Also, higher viscosity (thicker) oils need more time to reach engine operating temp. because absorb heat slower than lower viscosity oils.

No the majority of wear occurs during warmup until the oil additives are activated. Nothing to do with parts getting oil a bit later.

And thicker oil heats up faster than thinner oil.

 

[Japanese]

And thicker oil heats up faster than thinner oil.

Any supporting docs on that?

 

[OVERKILL]

Any supporting docs on that?

Yes, there's data that has been presented on it in the past that can likely be found using the search fuction. Thicker oil introduces more friction in things like the bearings, which in turn generates more heat in the fluid itself. Of course as this happens, it thins.

 

[Japanese]

Thicker oil introduces more friction in things like the bearings, which in turn generates more heat in the fluid itself.

Yes, I've heard that many times but it doesn't have to do with how fast an oil absorbs heat be convection from objects.
It's just the oil heats up of its own flow resistance. And when does that, at any ambient temp?

I presented articles on how lower viscosity reaches engine operating temp. quicker than higher viscosity oils. One source was Valvoline and the other one was AutoZone. Both of those sources are on here. From last time we're talking about the same thing with tired and Hohn.

 

[kschachn]

Yes, I've heard that many times but it doesn't have to do with how fast an oil absorbs heat be convection from objects.
It's just the oil heats up of its own flow resistance. And when does that, at any ambient temp?

I presented articles on how lower viscosity reaches engine operating temp. quicker than higher viscosity oils. One source was Valvoline and the other one was AutoZone. Both of those sources are on here. From last time we're talking about the same thing with tired and Hohn.

That of course is not what you said in your post. Moving the goal posts again in an attempt to support an incorrect statement.

You do that a lot because you really, really want your overall premise to be true.

 

[Japanese]

That of course is not what you said in your post. Moving the goal posts again in an attempt to support an incorrect statement.
You do that a lot because you really, really want your overall premise to be true.

That is what you think but is not the truth.
The fact that anyone repeats that and doesn't present documents makes me think that those are two different things - oil resistance flow and oil's ability to absorbs heat. I agree with the first one and am asking you for documents about the second one.

 

[kschachn]

That is what you think but is not the truth.
The fact that anyone repeats that and doesn't present documents makes me think that those are tow different think - oil resistance flow and oil's ability to absorbs heat. I agree with the first one and am asking you for documents about the second one.

Also been discussed in here in great detail. You can find it. I know you can.

 

[OVERKILL]

Yes, I've heard that many times but it doesn't have to do with how fast an oil absorbs heat be convection from objects.

That would be specific heat capacity, which can vary wildly between oils of the same grade. See this old article for example:
https://www.researchgate.net/public..._COOLING_OF_SOME_GRADES_OF_ENGINE_OIL_SAMPLES

Back in the day (2005) @MolaKule noted that generally, a thinner oil moving faster, would transfer more heat, despite having a lower heat capacity. Which brings us back to the subject of the pump being on the relief or not. Of course the pump being on the relief and itself generating heat, is heating the oil that's being bypassed through the relief due to mechanical and fluid friction in the pump.

It's just the oil heats up of its own flow resistance. And when does that, at any ambient temp?

I'm not sure what you are asking here? It's not just the flow resistance, the action of the shearing in the bearings generates heat, a more viscous fluid generates more heat through this action. This happens at every point along your temperature curve, fluid friction and heat generation through shearing forces will be higher than with a thinner fluid. This heat ends up in the fluid.

I presented articles on how lower viscosity reaches engine operating temp. quicker than higher viscosity oils. One source was Valvoline and the other one was AutoZone. Both of those sources are on here. From last time we're talking about the same thing with tired and Hohn.

I've seen Autozone assert that thinner oil "allows your engine to warm-up faster", with absolutely no footnoting or supporting documentation. Given how often the Winter grade is referenced incorrectly by website and even some oil manufacturers, I'd be looking for more concrete sources, such as this thread:

O

Thread 'Sources of engine heat and effects of oil viscosity'

Oct 12, 2018

in general, what % of engine heat is generated by viscous shearing, combustion or friction? Anything else terminology wise? Is viscous shearing a component of friction which is causing the heat, and heating up the oil which is heating the block ...

I always thought that most of the engine heat is from combustion ... viscous shearing was mentioned in one the recent threads on this forum and made me wonder about the percentages.

my final question and as much as I enjoy it,

it is not my intention to turn this into thick vs. thin...

• OilUzer
• Replies: 66
• Forum: Passenger Car Motor Oil (PCMO) - Gasoline Vehicles

 

[Hohn]

Because of the truly small difference between a -30 and a -40 grade at operating temperature. I used a -40 grade at times in my old ECHO with a 1.5L manual and no way I could feel "pretty clearly" that it wasn't a -30 grade.

But hey, if you can, you can.

And I swear my lawn mower GAINED power after switching it over to black bottle synthetic VR1 20w-50.

But I’m pretty sure that’s real because of the heavy friction modifier package and being splash lube with no oil pump losses.

 

[Hohn]

That would be specific heat capacity, which can vary wildly between oils of the same grade. See this old article for example:
https://www.researchgate.net/public..._COOLING_OF_SOME_GRADES_OF_ENGINE_OIL_SAMPLES

Back in the day (2005) @MolaKule noted that generally, a thinner oil moving faster, would transfer more heat, despite having a lower heat capacity. Which brings us back to the subject of the pump being on the relief or not. Of course the pump being on the relief and itself generating heat, is heating the oil that's being bypassed through the relief due to mechanical and fluid friction in the pump.

I'm not sure what you are asking here? It's not just the flow resistance, the action of the shearing in the bearings generates heat, a more viscous fluid generates more heat through this action. This happens at every point along your temperature curve, fluid friction and heat generation through shearing forces will be higher than with a thinner fluid. This heat ends up in the fluid.

I've seen Autozone assert that thinner oil "allows your engine to warm-up faster", with absolutely no footnoting or supporting documentation. Given how often the Winter grade is referenced incorrectly by website and even some oil manufacturers, I'd be looking for more concrete sources, such as this thread:

O

Thread 'Sources of engine heat and effects of oil viscosity'

Oct 12, 2018

in general, what % of engine heat is generated by viscous shearing, combustion or friction? Anything else terminology wise? Is viscous shearing a component of friction which is causing the heat, and heating up the oil which is heating the block ...

I always thought that most of the engine heat is from combustion ... viscous shearing was mentioned in one the recent threads on this forum and made me wonder about the percentages.

my final question and as much as I enjoy it,

it is not my intention to turn this into thick vs. thin...

• OilUzer
• Replies: 66
• Forum: Passenger Car Motor Oil (PCMO) - Gasoline Vehicles

I think people are confusing transferring heat with generating heat.

Thinner oils will transfer heat faster because they have higher flow rate and lower oil pressure.

Thicker oils will GENERATE more heat because they have more viscous friction and require more shaft work to turn the oil pump. More shaft work means more heat, the physics are pretty unassailable on that.

So the answer to which warms up faster depends on how what you are measuring and considering to be the “faster warm up.” If you are thinking about OIL warming faster, then thinner oils almost certainly warm up faster because they are circulating more and taking more heat away from the warm surfaces like the cylinder heads.

But the thicker oil is requiring more fuel to pump, generating more heat in the cylinders which warms the pistons, block and heads faster. But due to the lower flow, that heat is not as transferred to the oil. And the thicker oils has a lot more fluid shearing going on, which is warming the oil as well, perhaps it offsets the higher circulation of the thinner oils.

Either way it’s a TINY difference. With the SAE 40 and a 28F start, I had heat blowing in 2 blocks. About the same as it was with a 15w-40 and with the Valvoline Restore and Protect 5w-30.

 

[Hohn]

For certain his is also looking for maximum wear protection. If I was looking for a used car I'd like to find his because I know he protected it well.

The 4GR-fse in my IS250 when I got it with 107k on it had the phaser rattle and some minor carboning on the top end (minor compared to the gunk-infested specimens that drove the carbon-lock TSB).

When I sold it with 177k on it, it had no phaser rattle and a clean top end. Pretty sure the guy was happy with the $4k used car he found as I sold it cheap for what it was.

 

[OVERKILL]

I think people are confusing transferring heat with generating heat.

Thinner oils will transfer heat faster because they have higher flow rate and lower oil pressure.

Thicker oils will GENERATE more heat because they have more viscous friction and require more shaft work to turn the oil pump. More shaft work means more heat, the physics are pretty unassailable on that.

So the answer to which warms up faster depends on how what you are measuring and considering to be the “faster warm up.” If you are thinking about OIL warming faster, then thinner oils almost certainly warm up faster because they are circulating more and taking more heat away from the warm surfaces like the cylinder heads.

But the thicker oil is requiring more fuel to pump, generating more heat in the cylinders which warms the pistons, block and heads faster. But due to the lower flow, that heat is not as transferred to the oil. And the thicker oils has a lot more fluid shearing going on, which is warming the oil as well, perhaps it offsets the higher circulation of the thinner oils.

Either way it’s a TINY difference. With the SAE 40 and a 28F start, I had heat blowing in 2 blocks. About the same as it was with a 15w-40 and with the Valvoline Restore and Protect 5w-30.

Of course the difference in flow only happens when the pump is on the relief, otherwise the same volume of fluid is being moved through the system, that's a necessary dynamic to this discussion. If flow is the same, the fluid generating more friction is clearly heating up quicker AND being exposed to those same surfaces as the same rate; is circulating the same.

 

[Japanese]

I'm not sure what you are asking here? It's not just the flow resistance, the action of the shearing in the bearings generates heat, a more viscous fluid generates more heat through this action. This happens at every point along your temperature curve, fluid friction and heat generation through shearing forces will be higher than with a thinner fluid. This heat ends up in the fluid.

I was trying to say that even the oil heats itself when thicker at certain temp. (let's say 5°F or 0°F) touches a bare metal which is with that same temp. So that doesn't cool down the oil?

If it's proven that higher viscosity oil heats up more flowing at operating temp. that doesn't mean that it heats up the same way when the engine is cold because the convection with the metal cools it down. How that is taken in account at low temps and at what temps?
When the engine is at operating temp. its part are hotter than the oil but when is cold? So the temp. increase from the flow resistance is not the same at any engine temperature.

 

[Hohn]

Of course the difference in flow only happens when the pump is on the relief, otherwise the same volume of fluid is being moved through the system, that's a necessary dynamic to this discussion. If flow is the same, the fluid generating more friction is clearly heating up quicker AND being exposed to those same surfaces as the same rate; is circulating the same.

Even positive displacement pumps have slightly varying efficiencies, so it’s technically not identical with viscosity even when not in bypass.

But it’s effectively constant for our conceptual purposes.

What the “less flow in thick oil” crowd doesn’t want to hear is that PD pumps generally INCREASE efficiency with viscosity because there’s less internal leakage. Gear pumps and gerotors alike share this tendency.

So in terms of output flow vs swept volume rate (i.e volumetric efficiency) higher viscosity actually raises efficiency.

Not enough to really matter, but it’s a real thing.

 

[TiGeo]

Blind Pepsi challenge or get out.

 

[ZeeOSix]

Obviously the colder the temperature, the thicker the oil, and nobody would know for sure how much the oil pump is in relief on a very cold start without a specific test to verify ... but I'm betting most are in relief for a short time with a very cold start-up. And modern cars fire up with a fast idle, which makes it more likely there is some pump relief going on. An engine can tolerate some pump flow cut-back if it's designed right. No engine should be on the edge of destruction just because the oil pump goes into pressure relief. Of course, like always ... use the recommended W grade for the expected minimum cold start-up conditions.

 

[ZeeOSix]

What the “less flow in thick oil” crowd doesn’t want to hear is that PD pumps generally INCREASE efficiency with viscosity because there’s less internal leakage. Gear pumps and gerotors alike share this tendency.

As a reference point, the LS pump from Melling is ~85% efficient with 5W-30 at 200F per their pump test data (I've posted the graphs in other threads). Probably more efficient with thick cold oil, like 90-95% (my estimate). Of course the pump's efficiency will depend on the design and how tight the internal clearances are. But regardless, if the oil is thick enough combined with enough engine revs the pump will hit pressure relief and start cutting flow to the engine, and once the pump is in relief the pump efficiency goes out the window because the pump is operating on output pressure. The pump going into relief isn't really a bad thing if the system is designed right and not on the edge of destruction because the pump is under sized and/or goes into relief too early and too far for the operating conditions.

 

[Hohn]

Obviously the colder the temperature, the thicker the oil. Nobody would know for sure how much the oil pump is in relief on a very cold start, but I'm betting most are for a short time. And modern cars fire up with a fast idle, which make is more likely there is some pump relief going on. An engine can tolerate some pump flow cut-back if it's designed right. No engine should be on the edge of distinction just because the oil pump goes into pressure relief. Of course, like always ... use the recommended W grade for the expected minimum cold start-up conditions.

I was talking to some colleagues at Fleetguard several years ago about how they arrived at the sky-high pressure pressure requirement for the oil filters.

It was the result of arctic cold testing showing oil pressure spikes (briefly) of 300+psi that could sometimes rupture a marginal filter. This, with a full functional pressure relief in the pump. The relief sometimes can’t act as fast as the pressure wave propagates through the system.

That’s one reason why Fleetguard cans are pretty thick and notoriously tougher than some others.

 

[ZeeOSix]

Another thing, as show in the Esso cold start video in post 293, when the oil is super thick it's going to put the pump deep into pressure relief and most likely a big factor on why it takes so long to get oil flowing to all parts of the oiling system - ie, the flow they showed to the overhead cam. If the pump is putting out way less flow volume, then it's going to take longer to get that reduced flow throughout the oiling system. And that's just to the parts that are fed by pressurized oil. The parts that rely on splash or fling is another aspect to be concerned about.