Synthetic vs conventional oil's effects on stator longevity

[open1mind]

Like all oil-related questions concerning real-world effects, the correct answer is, "we don't know".

Where have you read that synthetics have a greater specific heat than convention oils? I've never heard that before.

I have never read that either BUT--- many Synth manufacturers and fans of the type claim that Synth oil keeps the MOTOR running cooler due to lower friction. So it would stand to reason that a lower oil/motor temp MIGHT keep the stator itself cooler?

The best myth is one that cant be disproven-- so this thread is a gem.

[RichDesmond]

I have never read that either BUT--- many Synth manufacturers and fans of the type claim that Synth oil keeps the MOTOR running cooler due to lower friction. So it would stand to reason that a lower oil/motor temp MIGHT keep the stator itself cooler?

The best myth is one that cant be disproven-- so this thread is a gem.

Same as every other oil or additive thread.

[rustybronco]

Even if you showed that it ran a degree or two cooler, (which I doubt it would) you still wouldn't know. The only way to know if it has a real, real-world effect is to run a few dozen motors, split between conventional and synthetic, on computer controlled dynos for a thousand hours or so and see if the wear rates and failure rates for the synthetic oil motors are lower.

Which brings up another thought. A good friend of mine works in the dyno lab a FOMOCO.

I need to ring him up.

so people just make up theories, or cherry pick lab data, and draw unsupported conclusions.

Did you read the Petro Canada link I provided and draw your own conclusion? or did you just wing it as well?

[Nessism]

Dale,

I seriously doubt there is a difference in the heat conductivity between different oils. Even if there were though, I don't think the stator gets much oil thrown on it anyway. That's one of the reasons I don't believe stator heat contributes in a significant way to engine oil temp.

[tatu]

I agree, I suspect what contributes stator failure more than anything is infrequent oil changes.

[rustybronco]

Ed, I don't believe the stator contributes very much to the engine oils heat either. It's not that high of a wattage device. What I was wondering is if engine oil against the stator and (or) aluminum cover kept the heat from being transferred, or helped it transfer heat or has little effect on transfer?

It's been shown engine oil has an affect on the epoxy used to hold the winding's in place on the stator. Now is that discoloration caused by a chemical reaction, or heat retention?

Just thinking out loud.

[rustybronco]

I agree, I suspect what contributes stator failure more than anything is infrequent oil changes.

As a result of the oil's thickening?

What about the decrease in the oil level from evaporation (??) when using a conventional oil?

[tkent02]

Even if there were though, I don't think the stator gets much oil thrown on it anyway.

I bet at 6,000 or 8,000 RPM oil is going everywhere in there, and going very fast.

Not sure how we can find out other than making a cover with a clear window like on Agemax's clutch.

[rustybronco]

Which adds another factor to all this. Does the increase in the flywheels speed contribute to or detract from oil retention in that area?

RichDesmond is correct. The only way to know for certain is through testing.



Sorry all, It's snowing outside, I'm sick and stuck at home waiting on a few parts to breadboard a project.

Beats arguing in off topic!

[tkent02]

Yeah, less anger and name calling for sure. I just looked at a 550 case, there is a window under the crankshaft, at the level of the raised "floor" of the case under the crankshaft. That's the only acess for oil that I can see to the stator cover, in or out. Is the oil normally pooled up un this area or does it usually run down into the lower area of the oil pan and around the transmission? If it's pooled up it seems like the rotor would sling it everywhere. But the stator sits inside, not outside the rotor. Maybe the flying oil cools the cover and the stator is cooled only by contact with the cover?

I guess I don't know where the oil goes when it's running, except it doesn't hang around by the sight glass.

I also have a 2v 750 engine here that was run low on oil until a piston broke, and some other stuff. I wonder what that stator looks like? I'll find out pretty soon.

Edit, that stator looks just fine, no burning or anything.

[tatu]

As a result of the oil's thickening?

What about the decrease in the oil level from evaporation (??) when using a conventional oil?

No I was thinking that the metal particles in the oil that is there causing problems. with magnetism and any route through the varnish.

[Gorminrider]

surely Air/oil vapour does circulate. It has to, so close to the flywheel...I have to assume it's about the same temp.
But painting the sidecover black might help transfer heat directly from the stator...maybe more can be done.

Tom203's post here seems to think that the oil makes stator burn worse

http://www.thegsresources.com/_forum/showpost.php?p=2024452&postcount=17

however I can't help thinking that the OEM winding insulation itself must be pretty poor to burn before the oil does...and that it should be likely to burn in air, not oil..

and that rustybronco's argument is fine if synth will lower the temperature below that where the insulation does degrade in vapour or liquid form- that need be shown.


Anyways, it's always been a bad idea to be on an aircooled bike sitting in traffic in the summer. Being Happy like Tkent's bikes are and hopefully mine too, spinning along revving free in the breeze is my best hope to keep the stator alive. Though, the black paint is beginning to appeal to me

[mrbill5491]

In my humble opinion, it was just a crap designed system from the git go.

[tkent02]

Then why do some of them still work fine after 35 years?

[mrbill5491]

Then why do some of them still work fine after 35 years?

Operative word there is some not all. Mine was crap. There is always some that work just fine, not the majority by any means.