30W Oil Suitable For Wet Clutch

[BusyLittleShop]

but that's not true at all when talking about the required film thickness between moving parts to give adequate lubrication.

Blackstone Labs data addresses your concerns about film strength...

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.

 

[BusyLittleShop]

Don't use Castrol Edge Synthetic, it made the wet clutch in my ATV slip and damaged it so it would slip when cold until the oil warmed up with Rotella t6 5W40 .

Under scrutiny you'll find that your slip was due to normal
glazing and the build up of contaminates during high mileage...
No one complains about clutch slip when new...

If you wish high mileage clutch life then you have to invest is some
good old sweat equity...

Deglazing clutch plates ain't nothing new... no sir... back in the 70s
it use to be part of every savvy rider's maintenance plan... and for
some reason that all change during the 90s... why fix what you can buy
new is the what you hear now a days... but if your interested in
making your clutch bite good as new then roll up your sleeves and read
on...

Inspect the friction plates for glazing... make sure you have plenty
of material to work with... your shop manual states clutch thickness
in thousands of an inch or mm...

First removed the contaminants with Acetone... pick a hard surface to lay
over a 600 grit black dry emery paper... rotate the clutch plate in a
circle... you're just busting the glaze... don't get carried away
remove too much material... You should end up with a friction plate
looks dull like a new one as opposed to a shinny glazed one... recheck
thickness...

Next check the pressure plates for bluing caused by localized heat...
make sure they are not warped... consult the manual for a thickness
range... now removed the contaminants with Acetone and wire wheeled
them to erased the blue and also to generally scuff up the surface...
you should end up with a dull surface free of Blue marks...

 

[ZeeOSix]

Quote Amsoil

60% of total engine wear occurs during cold start up
conditions before oil can circulate through the engine...

Quote Lake Speed Jr certified lubrication specialist at Driven Racing Oil.

“While a thicker viscosity grade is a workable solution, remember that
70 percent of engine wear occurs at start-up, so a higher viscosity
grade actually causes more wear, and we have used oil analysis that
shows this,” says Speed.

Quote 540Rat

"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."

Quote Frank McCowan, former Electrical /Mechanical Small and Large Equip.
Mech at Washington Metropolitan Area Transit Authority...

Listen to Jim Trainers answer below, it is mostly accurate. most
engine wear occurs during not only the first few minutes, but in the
first few seconds from when the engine is started.

Quote Jim Trainor, diy car maintenance guy

"The oil pressure takes a moment to come up and it takes a moment for
the oil to start circulating. There are bearing surfaces in your car,
called “journal bearings” that are quite literally two pieces of metal
separated by a film of oil that is delivered in under pressure in a
continuous flow. These surfaces do not touch when the engine is
operating normally. Other bearing surfaces, such as cam followers, and
piston rings, do touch but are subject to a continuous flow of
lubricating oil. When you start the car there are a few moments where
the oil is absent from these surfaces. Hence increased wear occurs."

Quote EAA ( Experimental Aircraft Association)

"When we first crank the engine, there's no oil pressure and the
crankshaft cranking speed is pathetically slow. The conditions for
hydrodynamic lubrication simply do not exist. Consequently, there is
metal-to-metal contact between the journal and the bearing, and wear
is inevitable."

The point of the photo is to graphically show the different rates of
flow between 0W 5Wand 10W... On a day with outside temp of 104F the 0W
still flows quicker during start that either 5W or 10W...

I want an SAE study or similar controlled test with data. Not a bunch quotes and claims from people with no data to study references, especially 540Rat.

Why aren't cars so much more worn out in the states with super cold winters where so many engines get started with very thick oil ? If cold starts were wearing out engines so much faster then there should be data that engines wear out noticably faster in Alaska and Canada then in California and Florida.

 

[ZeeOSix]

Blackstone Labs data addresses your concerns about film strength...

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.

Same old cut & pastes, lol. Film thickness and film strenght are not the same thing.

I've said this before, and I'll say it again ... Blackstone really doesn't know much about lubrication and tribology.

 

[BusyLittleShop]

I want an SAE study or similar controlled test with data.

Standby...

 

[ZeeOSix]

Most of the cold start wear studies I've seen talk mostly about cylinder and ring wear from rich A/F mixture, especially on carburated engines. Excess fuel washing down cylinders and reducing the viscosity and oil film (and therefore reducing lubrication) isn't good regardless if the oil is cold or hot.

I want to see a study that measures journal bearing and valve train wear vs oil viscosity over a wide temperature range of cold starts, and with a properly working oil filter ADBV to keep the oiling system galleries full of oil after shut down. Ideally, an engine that is "started and ran" by an external electric motor so that the cold start rich combustion A/F mixture is out of the factors, and it's all based on oil viscosity and cold start-up temperatures.

Engine design can also be a factor, depending on how well the oiling system is designed. For instance, if the engine has piston oil squirters then the cylinders will probably be better lubricated at all times including cold starts, and how the pump supplies oil to the valve train components could also make a difference on cold start-ups. I'd think (or hope) that good engine designers take extreme cold starts into consideration when designing the oiling system.

 

[Motu]

Most HDEO 15W-40's are recommended for Alison transmissions....surely Blackstone would know that ?

 

[Alain2]

Standby...

I am nowhere qualified to argue your technical positions, but here are couple general points;

1- The expected starting temperature of a motorcycle is never cold enough to benefit (wear wise) from a 5w vs 10w,
2- According to your logic, you would benefit from using 0w vs 5w, but you don't,
3- According to you logic, you would benefit from using 20wt vs 30wt, but you don't,
4- Engineers at Honda recommend 10w30 over 5w30. Engineers at Yamaha/Kawasaki/Suzuki recommend 10w40 over 10w30. I may not be able to justify exactly why, but it is reasonable to believe that they know 100x better than you,
5- Your positive experience with 5w30 is anecdotal.

Would I use or recommend 5w30 in a Honda or as 2 stroke gear oil? Mostly improbable.

 

[Robin127]

Thanks for the input everyone. I'll probably go with the Motul, I was planning on using their racing two stroke oil in the premix and I already use their 10W40 in a Ducati single I race and am very happy with it.

 

[Alain2]

Thanks for the input everyone. I'll probably go with the Motul, I was planning on using their racing two stroke oil in the premix and I already use their 10W40 in a Ducati single I race and am very happy with it.

Motul Transoil or motor oil?

 

[Chris142]

I have ran "car" oils as well as sae40 from the Auto parts store and never had a clutch issue.

 

[Robin127]

Motul Transoil or motor oil?

When I stripped the engine someone had put a really thick transmission oil in it, the stuff was like treacle.

I'll be using Motul 300V 5W30 Road Racing oil. The manual just specifies SAE30 engine oil, I would think that the Motul is better than the 70's/80's oil I used in it 40 years ago.