Petroleum oil better?


38 replies to this topic
  • letter

Posted September 30, 2007 - 06:56 PM

#1

In the November issue of Dirt Rider, there is an article by Ron Hinson on clutch inspection. Hinson says that petroleum oil is better than synthetic oil for the clutch. He says that on an engine where the same oil bathes the clutch and the top end one should use high quality pure petroleum oil and change it often. He says that in such an engine the oil will become contaminated from the clutch long before it degenerates so that the long-lasting benefits of synthetic oils are wasted. Does anyone have any comments?

  • 642MX

Posted September 30, 2007 - 07:12 PM

#2

Does anyone have any comments?


Of course I do. I talked to the guys at Rekluse about this synthetic vs dino oils. They recommended using a dino oil like Rotella 15W40 for best clutch performance. I asked them about engine protection, and they said it would be fine for the engine, but just change it often.

I do use a Rekluse, and I do use Rotella, and I change my oil every ride. 20 minutes or 20 hours, when the day is over, I change my oil.

Now, the other 1/2 of the YZF forum uses Amsoil. Which is a good oil, but its not recommended from the engineers at Rekluse.

  • grayracer513

Posted September 30, 2007 - 08:15 PM

#3

Does anyone have any comments?

Not without hearing something solid as to a rationale for this contention, no. I suppose I'll have to read the thing and see if it makes any sense.

I will say, however, that this:

in such an engine the oil will become contaminated from the clutch long before it degenerates so that the long-lasting benefits of synthetic oils are wasted.

...is wrong on two counts. First, it appears to assume that synthetics last longer than petroleum oils. They don't. At least not necessarily, when used in engines that share oil with a transmission. Synthetics resist oxidization better, and they resist acid build up and thermal degradation better (at least in general), but that's not what kills off the oil in these engines.

It is the shearing action of the transmission. and its destruction of the viscosity index improver (VII) additives that is the issue, and that leads to the second point. Only an oil that was purpose blended to be a gear lubricant, regardless of base, can survive for any length of time in a shared engine/trans application. The VII's used in even the best automotive and commercial engine oils are rarely up to the job, and neither are those in a surprisingly large number of specialty MC oils, and these will loose a startling amount of their viscosity so fast that it would amaze you. But a number of the best oils available are blended for the job, and not all among them are full synthetic. So, it a case of overgeneralizing, and of focusing on the wrong attributes to say that synthetics last longer.

Let me add that I have a full Hinson clutch in my '03. Calling that clutch a masterpiece is an enormous understatement. It is unquestionably the best motorcycle clutch I've ever owned or ridden with, and that evaluation is based on my experience with it, all of which has been with either Mobil 1 Racing 4T (formerly MX4T) or Amsoil MCF. The only other thing I would say is that to me, the clutch is an expendable item. I'm more concerned with engine and trans component protection than with the clutch, as long as it works OK.

  • letter

Posted September 30, 2007 - 08:49 PM

#4

Thanks for the replies. Gray, the article is very short; if you don't subscribe to Dirt Rider you can just glance at it at the supermarket if you get a chance. There's really nothing more to read in the article about the petroleum versus synthetic issue.

  • grayracer513

Posted September 30, 2007 - 09:48 PM

#5

That's what I planned on doing. The part that I dislike about this kind of thing is that it isn't much of a stretch to imagine that someone such as Ron Hinson might have a solid reason for such a statement, but unless some supporting facts or cause and effect are offered with it, it's just a gratuitous assertion, and has no credibility in any debate. That's too bad, because Mr. Hinson has certainly earned more respect than that.

  • YZ250F_Rider

Posted October 01, 2007 - 02:41 AM

#6

A couple of benefits of synthetics over dino is the resistance to coke up from heat, and it's resistance to dilution from blow by. Both of those tend to add longevity to synthetic.

Could be the line of thinking the guy was using.

  • grayracer513

Posted October 01, 2007 - 06:58 AM

#7

A couple of benefits of synthetics over dino is the resistance to coke up from heat, and it's resistance to dilution from blow by. Both of those tend to add longevity to synthetic.

Could be the line of thinking the guy was using.

It probably was, but as I said, it's usually the loss of viscosity due to the destruction of the VII's that occurs first, long before those attributes you mention come into play. It isn't inaccurate, it just usually doesn't get a chance to be a factor.

  • MichiganMXer

Posted October 09, 2007 - 05:31 PM

#8

I'm on my original clutch with my 2001 and I've used Valvoline 10-40 wet clutch 4 stroke motor oil the whole time.

Original top end too.

  • grayracer513

Posted October 09, 2007 - 08:29 PM

#9

My '03 had the OEM clutch replaced with a Hinson when it was nearly new because the stock clutch behaved badly. I bought it in the spring of '04, and since then, that same clutch, which still works better than any other I've ever owned, along with the rest of the bike, has racked up well over 300 hours, all of it on either Mobil 1 MX4T (now Racing 4T) or Amsoil MCF fully synthetic oils. The engine, BTW, will still hold over 97% on a leak down test.

So what's your point?

  • BergArabia

Posted October 10, 2007 - 06:56 AM

#10

I use synthetic oil and change regularly.
Synthetic oil always made my car run cooler..
So I was thinking the same benefit might happen in the bike..
Any thoughts?

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  • ncmountainman

Posted October 11, 2007 - 07:05 AM

#11

my technical knowledge of oil is lacking to say the least, but i've got alot of real world experience with it. i also run a rekluse clutch and they give great feedback of what oil they like and don't like. (i'm guessing its the precise and consistant engagement everytime that lets you get a better handle on it) as stated rotella 15-40 seems best,in 2nd delo 15-40 (seems to slip and run a little hotter as a recent change in the add pack has significantly more soluble moly,somewhere around 850ppm;which is borderline too much)
i have tried full synthetics alone and none have worked for me (mobil 1,rotella,and maxima) what has worked is a 50/50 blend;i used to use rotella 15-40 and mobil 1,but since the changes in mobil (i've heard through channels that their base stock is not as good as the old one) i've started mixing rotella 15-40 with maxima full synthetic(i forgot what they call it,but it ain't cheap) the maxima has extreme add pack for high heat (without high levels of moly or other slippery items) the V II's in the maxima must be superior to anything i've used because the the stuff just doesn't seem to break down, even when drained hot it still retains its original consistancy(but use max syn alone and the clutch gets a little chattery?). i've been a big fan of two2cool oil additive and use it religiously with whatever oil combo,it definately smooths engagement especially when hot. and when i just had my motor rebuilt by RPM's they could not beleive the lack of wear for the amount of hours and 2 yrs of HS races. anyway if any of you want to try the mountainman mix(50/50 rotella 15-40 and maxima's full synthetic i beleive its 10-40, and 2 oz per qt two2cool) feel free,it works great with the auto clutch. hey gray someone told me that full syn won't transfer the heat as well as dino,any truth to that?

  • SUnruh

Posted October 11, 2007 - 07:54 AM

#12

A couple of benefits of synthetics over dino is the resistance to coke up from heat, and it's resistance to dilution from blow by. Both of those tend to add longevity to synthetic.

Could be the line of thinking the guy was using.


phil,
maybe, maybe.

but in the face of reality is that with a flash point of only 365, 390 for amsoil and 390 for mobil 1 and then you see a flash point of oh say 445 or 465 for vavoline vr1, you know that is complete bs. when exxon superflo sae40 puts up a flashpoint of 440 after 2.9 hours of racing. i'm gonna side with the 79 cent conventional over the extremly expensive synth!!!

oh, and those synth's don't maintain their viscosity at all!!!

  • grayracer513

Posted October 11, 2007 - 08:30 AM

#13

Synthetic oil always made my car run cooler..


...someone told me that full syn won't transfer the heat as well as dino,any truth to that?


You see what the trouble with mythology is, don't you? There isn't really a lot of difference between them in terms of heat transfer, frankly. But synthetics do tolerate heat much better.

With regard to the question of Moly and friction modifiers, there's a couple of things you should know.

All molybdenum compounds are not created equal, or even for the same purpose, and are not friction reducers. In the first place, in hydrodynamic lubrication, there is no physical contact between the lubricated parts. The friction to be reduced exists between the parts and the lube oil. Secondly, when mpost people think of "moly", they think of the common dry lubricant, molybdenum disulfide, and conclude that this must be what is meant when moly oil additives are mentioned. In fact, moly disulfide is rarely used in oils. Most moly compounds are derived from moly dithiocarbamate, and many such compounds used in motor oils, especially in JASO MA oils rated for wet clutches, are "boundary lubricants", or "anti-wear" additves.

Boundary lubrication is what happens when the oil film fails to separate the moving parts for whatever reason. Originally, up to API SG/SH oils, this was done mostly by compounds like Zinc dialkyl dithio phosphate (ZDDP). This compound worked some what like spreading playing cards out on a table top. the ZDDP molecules would get between the two parts and physically separate them while sliding on themselves. But phosphorus was found to shorten the life of catalytic converters in cars, so the EPA ordered it reduced, resulting in oils with an API grade of SJ or higher temporarily having poorer anti-wear properties than the older oils did. Since then, recognizing the need for AW additives that do not reduce friction too far for some applications, oil additive companies have devised moly compounds that fit this need.

The moly compounds work differently, though. They break down under extreme heat and pressure and form a hard, bonded coating on the surface of the parts, which protects the actual metal surface from contact.

When you say that you add TTC to you oil and the clutch works better, you have used a friction modifier. Not that it was intended to be one, but that is the effect it had; it changed the friction between the clutch plates and the oil, and thus changed how they slide over each other as they engage. So you see, not even all friction modifiers are bad.

:confused:

  • SUnruh

Posted October 11, 2007 - 09:14 AM

#14

very well written richard!

  • grayracer513

Posted October 11, 2007 - 09:27 AM

#15

Thanks, Steve. :confused:

  • SUnruh

Posted October 11, 2007 - 09:59 AM

#16

even though you made it easy to read, will anyone actually comprehend what you wrote? :confused:

and to add on to your nice post, unless a person is being really stupid, they will change the oil long before the additives are used up, so the $$ oils really don't offer anything over the cheap ones. if an $$ oil doesn't hold up its viscosity, why even use it in the first place?
many use a lot of fancy marketing and tout certain tests they pass, but the real test is at 13,000 rpm in an blue F gearbox. it just chews the oil up faster than i can blink. the straight grade oils (ie don't have VII's (viscosity improvers)) hold up darn well. the diesel oils with their CF-4 and CF-4plus ratings were very good. the new formulas with CI-4 and CI-4plus don't seem to be able to handle the gearboxes as well. i've tested the new rotella t and delo400 and mobil 1300 and was NOT impressed. the real shocker of late is the SuperTech 15w40 CI-4 from walmart. went more hours with less shear than SRT (which was better than delo400 and 1300) AND had a better add pack. believe it!
now, if you want spendy, look no further than Motul 5100 10w50 or Maxima Ultra 4 15w50, both are very good with maxima getting the nod.

  • grayracer513

Posted October 11, 2007 - 11:15 AM

#17

even though you made it easy to read, will anyone actually comprehend what you wrote? :confused:

I have faith in most people's cognizant abilities.

if an $$ oil doesn't hold up its viscosity, why even use it in the first place?
many use a lot of fancy marketing and tout certain tests they pass, but the real test is at 13,000 rpm in an blue F gearbox. it just chews the oil up faster than i can blink. the straight grade oils (ie don't have VII's (viscosity improvers)) hold up darn well.

That is really the central issue with oils in applications like the YZF's where oil is shared with the transmission. All multi-grade oils use polymers called viscosity index improvers so that they can be a light, free flowing oil at low temps, and yet be no thinner at operating temperatures The majority of engine oils than a 40wt (for instance) is. These polymers are big molecules, as molecules go, and the less expensive, more easily made ones are subject to being torn to shreds by the kind of shear delivered by a transmission of any kind, particularly one connected to a high powered dirt bike that accelerates over uneven ground.

As you correctly pointed out, straight grade oils have very low levels of these additives, so the issue of viscosity shear down due to their destruction basically doesn't exist. However, there are VII additives available for use in multigrade transmission oils that are tough enough for such work. By far, most engine oils don't use these, as they are much more expensive, and generally of no advantage to an engine. But they are necessary for engines like the YZF, and a few good multigrade synthetics do use them.

The test most often used to test viscosity retention in polymer bearing oils is ASTM D-6278. This test heats the oil to 100 degrees C, then runs a small quantity through through a diesel fuel injector for 30 cycles. If you're not familiar with diesel fuel injectors, you should understand that they typically require oil pressures of 1500-2500 psi to "fire" them, and the shear forces applied at the pintel valve is easily equal to that encountered in a typical transmission. This was the test used by Amsoil in their Study of Motorcycle Oils. Looking at the way this test was conducted for this study (see page 9), you will see that:
> While the test procedure calls for 30 cycles, the oils were run through the test 4 complete times, for a total of 120 cycles.
> A lot of very good oils failed this test by shearing out of grade
> Most of the ones that failed did so right away, during the first 30 cycle test

And you'll see that there is more than one oil available that will retain its viscosity due to the fact that it really was formulated to be used as a transmission lube as well as an engine lube. That's the simple difference. More and more oil blenders are realizing this, and more multigrade oils are becoming available with the right VII's, but how does one know?

Well, you can take the approach you chose of using straight grade oils, but most of those are not synthetic, and you miss out on certain advantages that way. Or, you can locate test information like this one, and pick one of the ones that made it. Another way would be to look on the oil's label for the presence of the API grade "GL-1", which means that the American Petroleum Institute has certified the oil as a legitimate gear lube, but AFIK, only Amsoil MCF/MCV carry that grade. Otherwise, you can do your own engine oil analyses, and see how your stuff works.

  • adamdf

Posted October 11, 2007 - 11:50 AM

#18

Yikes, the valvoline oil didn't do so great in that test. I have just switched to using valvoline as well, looks like i will be looking to switch to another oil yet again.

  • SUnruh

Posted October 11, 2007 - 12:52 PM

#19

what is most interesting about that test, is that it is not what i have found in real life of a blue f engine. or maybe i should caveat that by saying in MY engine with me at the controls and NO oil company sponsoring the tests.

why would a company sponsor such a test if they didn't know they would win it before hand?????
special batch, to win a test, to show everyone why you should buy their product -> marketing!!!

  • YZ250F_Rider

Posted October 11, 2007 - 02:10 PM

#20

be that as it may, amsoils fork oil is awesome.





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