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Slightly different oil question.


SirDoh

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Some of us run 10W-30 and others 10W-40.  Lets forget the winter part and focus on the 30 vs 40.  The manual says to run 10W-40 in warmer climates. That's fine on the face of it but since all 6 gen have the same kind of thermostat, they all run at the same temperature.  When the engine gets to 104°C the fan kicks in.  No matter where you are on the planet and whatever the weather, the engine won't see much above that (not for very long anyway).  So why 2 oils?

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Generation 8 manual only calls for 10w30, with no mention of hot or cold climates. You seem to be on the right track. What’s the point of changing the grade?

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1 hour ago, SirDoh said:

Some of us run 10W-30 and others 10W-40.  Lets forget the winter part and focus on the 30 vs 40.  The manual says to run 10W-40 in warmer climates. That's fine on the face of it but since all 6 gen have the same kind of thermostat, they all run at the same temperature.  When the engine gets to 104°C the fan kicks in.  No matter where you are on the planet and whatever the weather, the engine won't see much above that (not for very long anyway).  So why 2 oils?

As VFR78 rightly states the 8gen only specifies 10w30.

From what I've read and heard this is more about frictional losses at operating temperature when using a 30 over a 40 oil and achieving Honda's power specifications. However the 40 oil may offer better engine protection at high operating temps.

Many 8gen owners who are previous 6gen owners (like myself) continue to run the same 10w40 without issues in the 8gen. YMMV.

 

Oh No!  Sorry, I didn't want to start another Oil debate.

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I'm not going to touch the viscosity debate - each can do their own for their own reasons.  However, FWIW when I ran either a 10-30 or for a time 0-40 vs 10-40 (all 3 Mobil 1) in the 6th gen, I noticed a marked increase in the amount of magnetic swarf on the magnetic drain plug I use.  The biggest difference was with 0-40.   There was no way to objectively measure it other than visual inspection - with the 10-40 there is consistently a thin smear on the magnet and with the other 2 I found a significant blob hanging on, maybe the size of a small pea.  I didn't have to eyeball it - I noticed it immediately when the plug came out.  My oil changes are annual between 3,000 and 4,000 miles which is what I typically ride each season.  I can't explain any of it nor am I going to try - it's just what I found when I pulled the plug.   YMMV  

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18 hours ago, SirDoh said:

Some of us run 10W-30 and others 10W-40.  Lets forget the winter part and focus on the 30 vs 40.  The manual says to run 10W-40 in warmer climates. That's fine on the face of it but since all 6 gen have the same kind of thermostat, they all run at the same temperature.  When the engine gets to 104°C the fan kicks in.  No matter where you are on the planet and whatever the weather, the engine won't see much above that (not for very long anyway).  So why 2 oils?

Thermostat rating is fully-open setting and is start of temperature climb. Just cruising around town under partial-throttle is enough to fully open thermostat on bikes in 20C or 30C climates. Then fan kicks in @ 104C. However... 

 

Note that ambient air-temps outside changes delta-T across radiator and affects how much heat can be shed by radiator (BTU/sec).  As result, even though fan kicks in at same temp on both bikes, one in 20C and one in 30C climate, higher-temp one will end up with higher coolant & engine-oil temps  for same loads because radiator sheds less heat in same amount of time. Balance between heating-rate of cooling system vs. heat-shedding rate (BTU/sec) will be different and equilibrium temperature will be different.  Especially under higher-loads than just steady-speed cruising. Thus effect on engine-oils will be different. Install coolant-temp, oil-temp and oil-pressure gauges and you'll see differences easily.

 

In fact, on my track bike which sees continuous full-throttle usage, removing fan on track actually improves cooling as it allows more air to flow through radiator.  However, on 40C days, that's not enough and coolant-temps rises above 110-115C, I often get oil-pressure drops after 10-15 minutes on track as +125C oil thins from heat and 15000 RPM redlines. I've tried different oils and different viscosities.  The only solution I've found to this dropping oil-pressure is to use Motorex 10w50 Power Synt 4T full-synthetic oil. My friend who races ZX-10R actually has to use Motorex 10w60  in her bike to have sufficient oil-pressure. Motul 300v or 7100 didn't cure oil-pressure drop at high-temps.

 

But yeah, it depends upon your usage of bike more than ambient temps really. For cruising, commuting or touring, it probably won't make much difference.

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14 hours ago, Cogswell said:

I'm not going to touch the viscosity debate - each can do their own for their own reasons.  However, FWIW when I ran either a 10-30 or for a time 0-40 vs 10-40 (all 3 Mobil 1) in the 6th gen, I noticed a marked increase in the amount of magnetic swarf on the magnetic drain plug I use.  The biggest difference was with 0-40.   There was no way to objectively measure it other than visual inspection - with the 10-40 there is consistently a thin smear on the magnet and with the other 2 I found a significant blob hanging on, maybe the size of a small pea.  I didn't have to eyeball it - I noticed it immediately when the plug came out.  My oil changes are annual between 3,000 and 4,000 miles which is what I typically ride each season.  I can't explain any of it nor am I going to try - it's just what I found when I pulled the plug.   YMMV  

Thanks for useful data! Let me see if I understand this correctly:

 

10-40 = thin smear on magnet

0-40 = significant blob/small pea

10-30 = significant blob/small pea
 

I suppose one way to objectively quantify this over time is to rinse off the stuff captured by magnet with acetone into petri dish. Letting it dry and then weighing it. Store it in separate jars and continually add more metal powders over time with each oil-change to get a running average.

 

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On 6/15/2021 at 2:58 PM, SirDoh said:

 So why 2 oils?

It's only a guide because the bike was sold world wide and some places didn't have choice of grades... so Honda Engineering tested and approved all the grades to keep your knees in the breeze... now a days with the internet buying it's easier to order Honda's preferred grade of 30... they know running a 30 grade will meet and exceed your mileage expectations because flow is more important than film strength... since 98 I been running 5W30 Mobil 1 year round in the RC45 during 100º + days... were mercy it feels like I'm riding in jet exhaust...

 

We say oil are graded on thickness but oils are actually graded on
flow... a 30 flows quicker with less energy than a 40 which means a 30
will increase horsepower and decrease operating temps with no loss in
longevity... oil drag is real...
 

Oil grades are separated by 10 points like 30 and 40 but that is NOT
to imply 10 grade points difference in thickness... Between a 30 and
40 can be as little as .02 difference in gravity flow... blink you'd miss it...

 

full-45634-35394-viscositytest1.jpg

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18 hours ago, DannoXYZ said:

 

In fact, on my track bike which sees continuous full-throttle usage, removing fan on track actually improves cooling as it allows more air to flow through radiator.  However, on 40C days, that's not enough and coolant-temps rises above 110-115C, I often get oil-pressure drops after 10-15 minutes on track as +125C oil thins from heat and 15000 RPM redlines. I've tried different oils and different viscosities.  The only solution I've found to this dropping oil-pressure is to use Motorex 10w50 Power Synt 4T full-synthetic oil. My friend who races ZX-10R actually has to use Motorex 10w60  in her bike to have sufficient oil-pressure. Motul 300v or 7100 didn't cure oil-pressure drop at high-temps.

 

 

Flow is what really lubricates our engines not pressure... pressure
and flow are inverse proportional... you can have pressure at the
expense of flow... an increased in flow will show as a decease in temps
the oil... an increase in flow works harder to separate the engine
parts that are under very high stress... an increase in flow means
less internal drag and more HP at the rear wheel...
 

Race teams only run 30 Grades all year because it gives the right flow at racing operating
temperature and that would be the viscosity of 10 at operating temps... so that
means for every 1000 rpms increase of oil pressure increases another 10 psi... a 30 Grade
flows more oil at higher rpms which flows more oil between the critical bearings
which carries away more heat and your not wasting HP just pumping oil through the blow
off valve... 40wt and 50wt builds pressure at the expense of flow and they waste HP by blowing

oil through the pressure relief valve...

 

30 Grade psi
1000 10
2000 20
3000 30
4000 40
5000 50
6000 60
7000 70
8000 80
9000 90
10000 99
11000 99 blow off by the pressure relief valve

 

40 Grade psi
1000 12
2000 24
3000 36
4000 48
5000 72
6000 84
7000 96
8000 99 blow off by the pressure relief valve
9000 99
10000 99
11000 99

 

50 Grade psi
1000 15
2000 30
3000 45
4000 60
5000 75
6000 90
7000 99 blow off by the pressure relief valve
8000 99
9000 99
10000 99
11000 99

 

We should learn that flow is what really lubricates our engines not
pressure... pressure and flow are inverse proportional... you can have
pressure at the expense of flow... an increased in flow will show as a

decrease in oil temps... an increase in flow works harder to
separate the engine parts that are under very high stress... an
increase in flow means less internal drag and more HP at the rear
wheel...


You see  I went to trouble to installed a digital oil pressure gauge on
the RC45 to learn... 30 grade at 8000 rpms 82 Psi close enough to perfect...

 

RC45Coolant203FOil10.JPG.d278b5159460b80
Mr.RC45Oil85Psi.JPG.c3e834643564c88284f7
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How does an aeroplane stay afloat? Where is higher-pressure area on its wings? And what velocity is this flow relative to other side of wing?

 

If flow is all that matters, why don't we use water or kerosene as engine-lube? Those will certainly flow more and faster than oil. 

 

Try these tests:

 

1. turn on air-compressor @ 50psi, put on sprayer nozzle and aim up. Put spray-can cap over nozzle and push button.

2. turn on air-compressor @ 100psi, put spray-can cap over nozzle and push button.

 

Which cap flies higher and faster? What's difference between two tests?

 

3. turn on air-compressor @ 50psi, put on sprayer nozzle and slide balloon over end. Press button for 1-sec.

4. turn on air-compressor @ 100psi, put on sprayer nozzle and slide balloon over end. Press button for 1-sec.

 

Which balloon received more air-flow? Why is that?

 

Pro-teams also upgrade their radiators to keep coolant-temps and oil-temps down. They are not experiencing high-temp oil-viscosity break-down. So they can use lower-weight oil for less shear-friction. But, they also rebuild engines many times during single season. Most street-riders will not swap out radiators on super-hot days or when taking their bikes to track 5-10x per year. Or rebuild engines several times a year.

 

I've blown up at least 15 race-engines due to insufficient oil-pressure. Always shown oil-pressure light prior to destruction. Never, ever blown up one when oil-pressure light stayed off (other than headgaskets from getting greedy with boost ;)). These are latest rod-bearings from brand-new engine with less than 20-hrs track time on them using 10w30 oil with flickering oil-pressure light on track.

 

uc?export=download&id=1hdTDNw9NRYiDRNFAf

 

Rebuilt engine and used 10w50 oil. Went through 2 seasons (45 days @ track/year), ~500hrs. Pulled engine apart in off-season to inspect. Bearings were still brand-new within clearance. So just put it back together. Going to inspect end of this season as it's coming around to 2-years again.

 

Again, if you're not constantly wringing out your engines 100% for hours on end on +40C days, it really won't make much difference.

 

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The "flow" we're interested in is difference in velocity between boundary-layer that's in contact with journal and bearing-surfaces vs. layers closer to centre of bearing clearance. Boundary-layer's velocity is zero relative to journal and bearing-surfaces. This difference in velocity creates the hydrodynamic wedge that lifts surfaces apart. Some good reading material:

 

https://www.sae.org/publications/technical-papers/content/260008/

https://ntrs.nasa.gov/citations/19910021217

http://www.cscos.com/wp-content/uploads/NY1389_Lubricants-and-Lubrication_Sachs.pdf

https://www.sciencedirect.com/topics/materials-science/hydrodynamic-lubrication

https://link.springer.com/article/10.1007/s11249-010-9612-6

https://mipsmed.wordpress.com/2016/02/17/journal-bearing-and-their-lubrication/

https://rotorlab.tamu.edu/me626/Notes_pdf/Notes02_App_1D_bearings.pdf <-- good maths and easier to understand if you unwrap journals and bearings onto flat surface

 

When people hear "flow" and "velocity", they think it's oil-volume flow from pump, that's really inconsequential. The velocity-differences between boundary and other layers of oil-film is much, much more significant and generates hydrodynamic wedge. Depending upon film-strength and surface-velocities, there's minimum speed needed to generate it. Low-RPMs generates lower layer velocities and wedge may not form. That's not same as low oil-volume flow from oil-pump.

 

 

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Neither pump pressure or flow. Most engine moving parts generate own lift for lubrication. Oil just has to be delivered or kept between interfacing surfaces. Viscosity is important as it is directly proportional to the lift generated, higher viscosity higher lift. This is again for lubrication. Cooling side function of oil system is different animal.

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Yes, just having oil in bearing-clearance is all you need. Trick is getting it and keeping it there. At higher-RPMs, oil is pushed out of clearances and needs to be replenished faster.

 

For example, in 1989, I dropped my VF500F in driveway and it toppled over onto rock on edge of driveway. Punched hole in lower clutch-cover and I lost all oil. Being stupid teenager, I just rode gently from Saratoga back to my brother's place in Milpitas; a 30-mile trip. With no oil. I kept RPMs low and throttle as low as possible, creeping along @ 50mph on freeway. My dad told me I probably destroyed engine.

 

We spent weekend replacing clutch-cover and taking oil-pan off to extract one rod-bearing for a look. Bearings & journal was fine!!! Amazing! So we buttoned up engine and it was fine. Drove back to Santa Barbara next weekend and engine was perfect for 15-years. Until I ran it with one clogged carb... but that's another story... 🙂

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1 hour ago, DannoXYZ said:

How does an aeroplane stay afloat? Where is higher-pressure area on its wings? And what velocity is this flow relative to other side of wing?

 

 

According to Newton s Second Law of Motion, also known as the Law of
Force and Acceleration, a force upon an object causes it to accelerate
according to the formula net force = mass x acceleration. F = ma

 

Simply put "Lift is a reaction force experienced by the airfoil due to its
turning of the flow downwards." Krzysztof

 

Fidkowski's video is my favorite for it explains intuitively how a wing works
Flow turning and it also debunks the popular theories like...

 

Equal transit time theory
Particle Kinetics theory
Venturi suck theory

 

Quote

 

 

 

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48 minutes ago, Magneto said:

Viscosity is important as it is directly proportional to the lift generated, higher viscosity higher lift.

 

Blackstone Labs test data shows higher viscosity is not as important as riders believe because they don’t find any
significant differences in wear, regardless of oil thickness...

 

The Importance of Viscosity?
Quote Blackstone Labs

The viscosity, or thickness of the oil, is not nearly as important
as many people think. Oil retains its nature no matter what thickness
it is.Think about this: automakers are continually recommending
lighter multi-grade oil in new engines. The reason is increased
efficiency. It takes power to pump oil through an engine, and the
lighter the oil, the less power required to pump it. The oil’s ability
to act like a solid and protect parts is not related to its thickness.
If that doesn’t sound quite right, consider this: The gears in a
heavy duty Allison automatic transmission are doing the same work as
the same machine equipped with an Eaton manual transmission. Due to
the hydraulics of the automatic, it runs on a 10W automatic
transmission oil.But the manual transmission uses a very thick
(sometimes up to 90W)gear lube oil. The gears of both types of
transmissions will have a similar life span. We don’t find any
significant differences in wear, regardless of oil thickness.

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3 hours ago, DannoXYZ said:

 

I've blown up at least 15 race-engines due to insufficient oil-pressure.

 

 

Mercy Danno... your blowing engines due to insufficient oil pressure from other reasons not because the oil is one grade difference in oil flow... our engines don't operate within a critical narrow margin of 2 to 5 centistokes in oil flow...

 

This reminds me of the Frog analogy...

Put 2 legged Frog in pan... heat pan and command jump... Frog jumps 4 feet...

Put 1 legged Frog in pan... heat pan and command jump... Frog jumps 2 feet...

Put 0 legged Frog in pan... heat pan and command jump... Frog jumps 0 feet because of loss of hearing...

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2 hours ago, BusyLittleShop said:

 

Blackstone Labs test data shows higher viscosity is not as important as riders believe because they don’t find any
significant differences in wear, regardless of oil thickness...

 

The Importance of Viscosity?
Quote Blackstone Labs

The viscosity, or thickness of the oil, is not nearly as important
as many people think. Oil retains its nature no matter what thickness
it is.Think about this: automakers are continually recommending
lighter multi-grade oil in new engines. The reason is increased
efficiency. It takes power to pump oil through an engine, and the
lighter the oil, the less power required to pump it. The oil’s ability
to act like a solid and protect parts is not related to its thickness.
If that doesn’t sound quite right, consider this: The gears in a
heavy duty Allison automatic transmission are doing the same work as
the same machine equipped with an Eaton manual transmission. Due to
the hydraulics of the automatic, it runs on a 10W automatic
transmission oil.But the manual transmission uses a very thick
(sometimes up to 90W)gear lube oil. The gears of both types of
transmissions will have a similar life span. We don’t find any
significant differences in wear, regardless of oil thickness.

Not apples to apples, and they are not saying viscosity doesn't matter.  I could design a transmission to run on Crisco, but it would be designed around the viscosity of Crisco, the speed of the bearing, and Crisco's working temperatures, and little else that matters.  It would keep those parts separate when running in the same manner as either the 10W or 90W.  There are multiple reasons why "the wear is the same," or could be the same, between those two things.  

 

Do not concur that "flow" lubricates, that doesn't appear in any equation for bearing design; in forced lubrication, flow is necessary to maintain the film, which is also directly related to the angular speed of the rotating bearing, or linear speed of the sliding surface, not flow out of ports.  The only design numbers for forced lubrication that we consider are that [Flow in] ~ [Flow Out], and we have a bunch of pretty charts and math to figure that out for different kinds of bearing interfaces and ports.  

 

In design we use forced lubrication for a number of reasons - primarily, cooling required to keep the fluid within a range - or else we could get away with sealed bearings everywhere and do away with complex cooling mechanisms.  Generally, that would be awesome...an oil sump and cooler in a small vehicle engine is nothing compared to the large and complex heat exchangers we use for very large power plants and machinery. 

 

By the book, Magneto and DannyXYZ are correct in referring to lift, a bearing is designed around viscosity of the oil.  The engine bearing and sliding surfaces are designed for higher viscosity oils to accomodate the required higher viscosity oil required for the transmission teeth, where elastohydrodynamic lubrication occurs under contact force between the teeth.  The space between the bearing and the journal surface is greater than if you designed it for SAE 0 or SAE 5 oil...you "can" run it lower, but there is higher bearing eccentricity.  Or,  the internal axis is further off center from the journal axis.  This has a number of downstream effects, from the obvious increased wear inside a single bearing, to all of the other wear that occurs when parts are in misalignment.

 

There is inherently some factor of safety and a holistic design requirement that Honda puts into their specifications.  And a race team will get direct support from Honda engineering on that point, while also having a different set of risk factors.  We can infer what they might be, but there is little upside to experimenting or trying to find an upper and lower limit.  We know running water would be bad, and molasses bad for opposite reasons.  No need to find out just how close Honda really thinks we can get to either through experimentation.  

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uh... gears don't use hydrodynamic wedge for lift lubrication. There's actual contact and EP/ET additives are used in pH basic solution. It's actual heat of contact that melts these additives into super-hard wear-resistant deposits on gear-surfaces. Note that there's not much oil-flow in transmissions. Flow is not needed for lubrication.

 

3 hours ago, BusyLittleShop said:

 

Mercy Danno... your blowing engines due to insufficient oil pressure from other reasons not because the oil is one grade difference in oil flow... our engines don't operate within a critical narrow margin of 2 to 5 centistokes in oil flow...

So you're saying flow-difference between different grades of oil is not significant?

 

Well, about 10 of these Porsche engines were victims mysterious "#2 rod-bearing" failures. Seemingly occurs when increasing redline beyond factory values on track cars. There was all sorts of theories for decades, improper internal passages in block and crank, rod-journals drilled on inside instead of outside surface, insufficient oil-pan baffling. All sorts of different grades of oil was used with thicker grades apparently not as vulnerable, but still not full solution. The only thing in common was oil-pressure light going on before self-destruction.

 

People developed all sorts of "fixes" for these symptoms. Cross-driling rod-journals, custom crank-scrapers and oil-pan baffles, and Accusump. The Accusump really helped during moments of low oil-pressure by supplementing additional oil when pressure from pump dropped (for whatever reason). Compared to all other "fixes", this one worked the best. However, it was still band-aid on symptoms, since actual cause was still unknown. But it was a clue in proper direction; that oil coming from pump was inadequate somehow.

 

It took an engineer using sophisticated ultrasonic recording equipment to finally figure out real cause of this oil-pressure issue. Something in pump was severely reducing viscosity of oil to less than 2-3 cSt at high-RPMs. Oil probably flowed faster than ever, but it wasn't lubricating bearings properly. This is where Accusump with a separate supply of un-molested oil really helped. I can't reveal more about this issue as there are class-action lawsuits going on and patents in the works on solution. Bottom-line, severely reduced oil-viscosity coincided with huge drop in oil-pressure, oil-light goes on, crank/rod-bearings self-destruct.

 

 

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8 minutes ago, DannoXYZ said:

uh... gears don't use hydrodynamic wedge for lift lubrication. There's actual contact and EP/ET additives are used in pH basic solution. It's actual heat of contact that melts these additives into super-hard wear-resistant deposits on gear-surfaces. Note that there's not much oil-flow in transmissions. Flow is not needed for lubrication.

 

 

 

They don't...but they do use something called elastohydrodynamic lubrication.  Under direct contact force, perpendicular to the surfaces pressed together, many/most fluids will "shear thicken" with a mathematical limit that is "way up there" and looks like infinity.  Somewhere I have those equations, I still have a hard cover copy of Mechanical Design.

 

Elastohydrodnamic lubrication was brought up in VFRD 1.0... 😎

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interesting... so it's like sand in a way. At low velocities, you push it aside and sink. But hit it harder and faster and it "thickens" to support higher loads.

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3 minutes ago, DannoXYZ said:

interesting... so it's like sand in a way. At low velocities, you push it aside and sink. But hit it harder and faster and it "thickens" to support higher loads.

In a way.  It's related to perpendicular force rather than speed though.  And this is an *ideal* case at time=0, the oil can obviously escape out both sides at some point and can't ultimately reach infinity.  And the gears are turning freely in between contacts and slinging oil away, etc.

 

We used to have another engineer on the board who worked at a very large diesel test lab, and he was really good about all of this.  I want to say he was the guy who pointed out the main difference in oil wear for motorcycles vs. cars is the transmission.  If you think about collapsing a column by pushing down on it in compression, when it busts out sideways in the middle that's shear forces acting on it where it ruptures.  Here that shear force is being applied to the oil.  So it is thickening...but it's also getting its teeth kicked in and breaks down faster than in a car or elsewhere.

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On 6/16/2021 at 11:26 PM, DannoXYZ said:

 

 

So you're saying flow-difference between different grades of oil is not significant?

 

 

Blackstone's 35 years worth of racing and street motorcycle oil analysis shows no significant differences in WEAR between the grades... in other words either your 60 grade or a 30 grade will meet and exceed your racing expectations... what is significant difference between a 60 and 30 grade is HP and Temps... the slower 60 consumes 2 to 3 more HP in energy than the freer flowing 30 grade...  a freer flowing 30 grade will run cooler than the slower 60 grade... Oil drag is real...

 

Quote Race Engine Builder 540Rat


SECTION 2 – MOTOR OIL VISCOSITY SELECTION

THE BENEFITS OF USING THINNER OIL:

• Thinner oil flows quicker at cold start-up to begin lubricating
critical engine components much more quickly than thicker oil can.
Most engine wear takes place during cold start-up before oil flow can
reach all the components. So, quicker flowing thinner oil will help
reduce start-up engine wear, which is actually reducing wear overall.

• The more free flowing thinner oil at cold start-up, is also much
less likely to cause the oil filter bypass to open up, compared to
thicker oil. Of course if the bypass opened up, that would allow
unfiltered oil to be pumped through the engine. The colder the ambient
temperature, and the more rpm used when the engine is cold, the more
important this becomes.

• Thinner oil also flows more at normal operating temperatures. And
oil FLOW is lubrication, but oil pressure is NOT lubrication. Oil
pressure is only a measurement of resistance to flow. Running thicker
oil just to up the oil pressure is the wrong thing to do, because that
only reduces oil flow/lubrication. Oil pressure in and of itself, is
NOT what we are after.

• The more free flowing thinner oil will also drain back to the oil
pan quicker than thicker oil. So, thinner oil can help maintain a
higher oil level in the oil pan during operation, which keeps the oil
pump pickup from possibly sucking air during braking and cornering.

• The old rule of thumb that we should have at least 10 psi for every
1,000 rpm is perfectly fine. Running thicker oil to achieve more
pressure than that, will simply reduce oil flow for no good reason. It
is best to run the thinnest oil we can, that will still maintain at
least the rule of thumb oil pressure. And one of the benefits of
running a high volume oil pump, is that it will allow us to enjoy all
the benefits of running thinner oil, while still maintaining
sufficient oil pressure. A high volume oil pump/thinner oil combo is
preferred over running a standard volume oil pump/thicker oil combo.
Because oil “flow” is our goal for ideal oiling, NOT simply high oil
pressure.

• Oil flow is what carries heat away from internal engine components.
Those engine components are DIRECTLY oil cooled, but only in directly
water cooled. And better flowing thinner oil will keep critical engine
components cooler because it carries heat away faster. If you run
thicker oil than needed, you will drive up engine component temps. For
example: Plain bearings, such as rod and main bearings are lubricated
by oil flow, not by oil pressure. Oil pressure is NOT what keeps these
parts separated. Oil pressure serves only to supply the oil to this
interface. The parts are kept apart by the in compressible hydrodynamic
liquid oil wedge that is formed as the liquid oil is pulled in between
the spinning parts. As long as sufficient oil is supplied, no wear can
occur. In addition to this, the flow of oil through the bearings is
what cools them.

 

Quote Endurance Racer Gmtech94

When I raced we were sponsored by an oil company and helped with the
research of their product .The thought at the time was to run 20w50
race oil to provide for the best lubrication under racing conditions
hence no oil related failures . After many races and a lot of real
data research the conclusion was in this case to run a 10w30 oil as it
provided better lubrication and less engine wear over a long period of
time ,remember endurance racing in 24 and 30 hour races . Although we
never had an engine failure due to oil properties we did have a lot of
feedback on engine wear as well as transmission and clutch wear . I
have to say we did abuse these bikes on occasion with spinning the
back wheel to turn the bike as well as the occasional fall .The
ignition was a weak link but I could change out the pulsers in about
17 seconds once the bike was in the pits . In conclusion 10w30 ran
cooler and did not break down as much as the thicker oils did.

 

Oil drag is Real...

full-45634-35309-oiltubeviscositytest.jp

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Dude...

 

A lot of that doesn't mean what you think it means.  It's certainly not a response to me.  And I'm not really sure where to begin with the conceptual errors between foil theory and bearing lubrication. 🤦‍♂️

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On 6/16/2021 at 11:22 PM, ShipFixer said:

We know running water would be bad, and molasses bad for opposite reasons.  No need to find out just how close Honda really thinks we can get to either through experimentation.  

Always enjoy your learned responses Patrick and I agree... in fact water is doubly bad... it has the viscosity of 1 so it will pump and it might flow fast enough to lift 5,000 lb vehicle off the ground or float a 59,000 lb Granite Ball but it will rust our engines whereas Molasses with the viscosity of 5000 ain't even a player because it will hardly move... I think Honda will continue to recommend the viscosity of 10 or 30 grades for our bikes...

 

The power of flow...

Water has the viscosity of 1 yet water flowing between the sphere and
its shaped holder lifts a 9 ton ball slightly where rotation can be
accelerated by your hand and feels friction less...

 

59,000 Pound Granite Ball Floating - Grand Kugel

 

Quote

 

 

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Raise your hand if you have an MS in Mechanical Engineering 🙋‍♂️

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