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Full Synthetic Oil in my Thumper

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Posted by: Streetsquid---------------------

I was flipping through one of the dirt bike monthlys at the local grocery store this week and I came across a little blurb that stated that it is very bad to use synthetic car oil in a thumper because the tranny rapidly breaks down the oil causing it to lose a lot of its lubricating properties required in the engine (I think it mentioned the crank specifically).

Now, without starting the big car vs. bike oil debate again, is this accurate (Rich, do you agree with this magazines statement)? I am concerned because I am using Mobil 1 full synthetic in my TT-R.


Posted by: dirtdad---------------------

Did the article happen to say just how/why full synthetic would break-down any faster than petro based motor oil? And just how long is rapidly? Most four stroke owners that I know or have heard, change their oil on average about every 3-5 hours of riding time! The oil probably gets contaminated more than breaks down in that amount of time. I think the article was most likely quoting someone or some company with an interest in selling moto specific oil at 6-8 bucks a pop! Just my opinion...and the debate rages on.

I personally think your TTR is doing just fine on the oil you're currently using.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by Streetsquid
(Rich, do you agree with this magazines statement)?


The day I start taking oil advice (or ANY technical advice) from THOSE tehno-impaired nitwits, will be the SAME day that pigs fly over my house while I'm standing in the yard holding TWO winning lottery tickets and watching Gomer work on MY bike. :scream:

Mobil 1 15w50 synthetic is an excellent oil for your TTR.
Keep in mind it's always a good idea to ignore technical "advice" from people who have ZERO proof (other than TRUST ME) to back up their ridiculous statements.


Posted by: SpeedyManiac---------------------

Rich, would it be the smae for an XR100R? Right now I'm running Castrol 10w40


Posted by: Rich Rohrich---------------------

Air cooled engines have the MOST to gain from running a quality synthetic oil, but changing to synthetic oil on a bike that has run it's whole life on mineral oil is asking for clutch and seal problems. I would keep using the Castrol and just keep it clean by changing it regularly.


Posted by: SpeedyManiac---------------------

Thanks for the tips, Rich.


Posted by: Idaho Charley---------------------

I was waiting for this topic to surface, since I saw the same picture and note in the July issue of Dirt Bike on page 15. The statement never to run synthetic oils in four strokes was attributed to Thumper Racing.

My first thoughts were what had prompted Thumper Racing to make such a statement? My perception is they are a reputable company and do tend to push the mechanical stress envelope on the new four strokes models. They may have experiences; which us with relatively stock bikes will not see. My opinion is that instead of dismissing the information due to where it was presented, the objective approach would involve contacting Thumper Racing and seeing if this information is based upon objective evidence/testing.

BTW - I'm a believer in synthetic oils and have been using them for over 20 years.


Posted by: sparkymarky---------------------

note that in thumpers catalog(page 53):
q. What oil should i use for Break in?
a. On break in, you should use a petroleum base motorcycle oil only for the first 10-15 hrs. After break in any motorcycle oil, petroleum base or synthetic will work fine.

they do recommend against car oils, in general, as do most folks, with the exception of mobil1 15-50.

magazines are stupid. don't believe them.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by Idaho Charley
My first thoughts were what had prompted Thumper Racing to make such a statement? My perception is they are a reputable company and do tend to push the mechanical stress envelope on the new four strokes models. They may have experiences; which us with relatively stock bikes will not see. My opinion is that instead of dismissing the information due to where it was presented, the objective approach would involve contacting Thumper Racing and seeing if this information is based upon objective evidence/testing.


I knew who made the statements in the mag it just didn't seem worth bringing up, but as long as it has . Just because a company has made a good living from wedging steel sleeves in late model plated barrels doesn't magically make it a cutting edge, forward thinking organization, or somehow make it's principals technically savvy enough to evaluate oils in a scientific way (no easy task BTW) .
The statements by Thumper (if quoted correctly by the magazine) are ridiculous, over generalized and in my experience about what I would expect from them. Ask Mr. Lechein of Maxima Oil if he agrees with Thumper's "views" on synthetic oil and he will probably herniate himself from laughing.

Feel free to take the advice that brings you the most piece of mind, because for average riders with good maintenance habits that's all you are buying at the oil counter anyway.


Posted by: ballistic---------------------

I saw the statement in the mag today and thought "..what a dipsh_ _".
Knowledgable bikers know the opposite is true.
Oh well, ignorance ain't a new thing.


Posted by: Streetsquid---------------------

Thanks Rich for the input. I haven't had any problems so far using the Mobil 1 so why stop This just reaffirms my belief.


Posted by: thumper kid---------------------

I agree with Rich. My dad has been using Mobil 1 15/50 for years; on all kinds of machines, and with wet and dry clutches and also low and high RPM engines. He's never seen an oil related problem so far, and also the engines have looked very clean upon teardowns. He still uses it now, even on his new KTM 520 exc-r.


Posted by: xrsforever---------------------

I am not going to disagree with what is said above. But I have heard XR riders who say synthetic oil can make an XR clutch slip. Most I know use a synthetic blend, I have been using a synthetic blend for years with no problems.


Posted by: Rich Rohrich---------------------

Riders who put big hours on a clutch using mineral oil and switch to synthetic are bound to have slippage problems. My XR6 had about 10k miles on the clutch using mineral oil (previous owner) and it was working well. Knowing I was going to put a clutch in anyway I switched it to synthetic to see how it would react. Within 50 miles the clutch was slipping . New clutch same synthetic oil, and lots of trouble free asphalt slides later the clutch was once again bulletproof on synthetic. The moral of the story seems to be, once you put serious time on the clutch, major changes are ill-advised. Oil seals seem to display a similar distaste for synthetic oil after they have aged on mineral oils.


Posted by: DualSportr---------------------

I know I'll get lots of grief for going up against Rich and the rest of the Synthetic gang, but here goes.

In working on high performance thumpers, the company I work for has seen significant problems with most synthetic oils.

If you talk to any of the aftermarket manufacturers out there who really work on four strokes, they will normally not recommend Synthetics, and they will recommend AGAINST any automotive synthetic.

The main problem we all see is this: In a built four stroke, the synthetic is just too thin to withstand the pressure on a cam/rocker setup. It also is made thinner by the heat of the clutch slippage and although it doesn't break down in the chemical sense, really thin oil is the same thing as broken-down oil.

We, and other performance shops (such as Thumper) have found that especially when it comes to the RFVC Hondas, and the smaller thumpers (al la TTR 125, XR 100, XR 200, etc), the use of an automotive synthetic oil can significantly reduce the lifespan of these engines (This is not as much a problem with shim and bucket, water cooled designs such as the YZF, which seem to handle synthetics better).

We see damage to the cam, rockers, rod small end, gears, etc. Although this damage can also be seen in an engine using a petroleum-based oil, it is not seen as frequently, and normally only seen after significant abuse or low-oil conditions.

Although I know there are many of you out there who have had years of good luck with synthetics such as Mobil 1, it's just that the views of those people who work with many of these engines on a daily basis DO NOT believe in synthetics.

The main reason for running a synthetic is that it lasts longer. Oil (especially in an air-cooled four stroke), shouldn't be around long enough to get into the longevity properties!

The engines we see with the prettiest parts are those which have run a good quality non-synthetic (or semi-synthetic) motorcycle oil which has been changed after every hard ride.

Gary from Thumper may have been paraphrased in the article, but he's a smart guy. He's seen lots of engines. He's not some gomer who's working in his garage. You may not agree with his theory on oil, but don't dismiss his qualifications to talk about four strokes. He makes his living doing just that.

There are many theories out there. Everyone has an opinion about oil. I guess it's up to each of us to decide who's pet theory we're going to believe.

It just seems to me that the people who see thousands of engines in their lifetimes have a better basis for making a determination than the general public. Even those of you who have owned twenty or thirty thumpers in your lifetime, how many of them have you actually torn into? How often to you see an engine that has bent a crank after a high-side in flat track racing? How many sets of worn cams and rockers have you inspected? How many pistons have you seen destroyed by a lean conditon caused by nitros?

There are many experts in riding technique, suspension setup, carb tuning, out there. There are very few experts in four stroke technology. Opinions are like you-know-what, everyone's got one. I just believe that it's smart to get your advice from people who have the most experience. Not just those who read the most, or who yell the loudest.

Technicians with four stroke experience will continue to use petroleum oils. Weekend warriors will continue to purchase automotive synthetics. Neither side will convince the other they are right.

PJ


Posted by: ballistic---------------------

What do the most expensive engines on earth use?
Top fuel cars, indy cars, nitro boats, nitro Harleys... do they not mostly,
if not exclusively, use 100% synthetic?


Posted by: Rich Rohrich---------------------

In the interest of furthering everyone's knowledge.

Just so everyone understands, PJ (aka DualSportr) works for Powroll so this is coming from a solid source.

PJ - You said the following in your post

Quote:
The main problem we all see is this: In a built four stroke, the synthetic is just too thin to withstand the pressure on a cam/rocker setup. It also is made thinner by the heat of the clutch slippage and although it doesn't break down in the chemical sense, really thin oil is the same thing as broken-down oil.


I've seen similar statements from other people in the motorcycle business, and the question that always comes immediately to my mind is how exactly do you guys determine that the wear/damage you are seeing can be directly related to a viscosity issue that is present in a synthetic oil but not in a similarly rated (say 20w50) mineral based oil?

This isn't meant divisively or to be contrary, but that's a fairly sweeping statement that flies in the face of a large amount of peer reviewed research and tons of empirical data from automotive and motorcycle sources. I for one know there are situations where special blend mineral based oils have shown advantages in extreme loading situations, but those mineral oils are NOT generally available to the racing public. While it's clear that not all synthetics are good, or appropriate for motorcycle use it strikes me as odd that synthetics would be summarily rejected as group by working professionals in the dirtbike business, yet embraced to a large extent by professional race engine builders in many other motorcycle and automotive fields.

So at the risk of opening the whole oil can AGAIN can you go into any more detail on the specifics?


Posted by: Shaw520---------------------

Quote:
Originally posted by DualSportr
The main problem we all see is this: In a built four stroke, the synthetic is just too thin to withstand the pressure on a cam/rocker setup. It also is made thinner by the heat of the clutch slippage and although it doesn't break down in the chemical sense, really thin oil is the same thing as broken-down oil.

PJ, Thanks for sharing your experience, your points are well taken.
Although it does seem that people who use synthetics, for some reason when doing so, they use oils of less viscocity. Could this be the cause of the wear you are seeing, or are you suggesting that a 20-50 dino oil has more viscocity than a 20-50 full synth ? :think curious


Posted by: dirtdad---------------------

And what about MOBIL 1 motorcycle specific. It's full synthetic and specified for four strokes. As far as I can tell, it's not made up chemically any different than their 15w50. All they did was offer it in viscosities that better match motorcycle manuals suggested ratings and slap a motorcycle on the bottle and charge about $4 more a bottle. The manuals for my YZ426 and TT-R125 DO NOT say anything about warning against the use of synthetics. As a matter of fact, Yamaha's preferred oil is Yamalube 4R which is a synthetic blend. I realize they push this to further their profit, but apparently feel there is no issue with the synthetic aspect of this oil. I'm curious also concerning the points made by Rich and Shaw520. What data is there that shows the wear was caused specifically by the use of synthetic vs dino as apposed to the frequency of oil changes, viscosity used, and the way the motorcycle was treated/ridden? Also, what data is out there that shows dino oils lubricate and hold up under extreme pressures better than synthetics. I've always been led to believe that synthetics are usually superior to petroleum based oils, but of course, I'm no engineer or chemist.


Posted by: ballistic---------------------

Yep, it puts the entire billion dollar synthetic oil industry on trial.
Even though the performance people who Dualsportr refers to have far most experience than most of us, that does not guarantee or prevent thier beliefs about oil from being wrong. Seems anecdotal, with all due respect. We've all seen the human tendacy for bandwagon jumping... this bandwagon being "lets fly in the face of the majority ".

Do not NASCAR's and Indy cars have extreme duty requirements for thier oil?


Posted by: dirtdad---------------------

I don't know what kind of oil the cars in NASCAR run as I'm not a follower of that series. I do believe though that most of us "low" budget users of performance bikes and cars should not go by what our favorite race car or bike supposedly running. I think they are either sponsor driven or very secretive about what they run. They also tear down their engines completely after each event or practice session so there is not much comparison with the way our motors are run or maintained. All of them openly endorse what they're paid to endorse. I'm not arguing the points made by DualSportr but I am interested in hearing some actual data on why synthetic does not perform better than petroleum based oils in hi-po 4-stroke
motorcycle motors when alot of performance car builders and manufacturers
recommend it. Heck, I don't even know of any M/C specific oils that are SJ rated like most car oils. Most are SH at best. Is this just a marketing thing?


Posted by: Rich Rohrich---------------------

Some Nascar teams working with Phillips 66 are experimenting with specially blended mineral based oils for certain types of tracks where the heat generated in the valve spring area has caused some durability issues. This $15+ per liter 15w40 oil is not generally available to the public, but it can be purchased. I'll be testing it in a heavily modified TTR125 this summer, and if I find out anything noteworthy I'll pass it along. Keeping an open mind and following the advances in the petroleum industry seems like the best approach in the end.

One of the more recent SAE papers on the subject of oil and race engines is:
2000-01-3553 Oil Development for Nascar Racing
authored by
Douglas T. Jayne and Gail A. Evans - The Lubrizol Corp.
Steven G. Wilson - Richard Childress Racing Enterprises
Arnold L. Shugarman - 76 Lubricants Co.
Tim Wusz - TOSCO Marketing Co.

The summary section is reproduced below

CONCLUSIONS
· RCR developed a dynamometer test that correlates
ring welding, wrist pin bore wear, and valve train
wear with Winston Cup Racing performance.
· Low detergent packages increase the effectiveness
of antiwear film formation which minimizes
microwelding. Calcium detergents performed better
than magnesium detergents which performed better
than sodium detergents in this study.
· The particular molybdenum compound chosen as a
top treatment for friction modification did not improve
valve train wear.
· Synthetic oils generally performed better than
mineral oils with similar additive packages.
· A 20W50 mineral oil showed equivalent
performance to a 10W30 synthetic formulated with
similar additive chemistry.

It's an interesting read for those who are looking for additional info on the subject.


Posted by: cujet---------------------

Quite a few years ago I worked for Mobil oil in the flight department. I did speak with engineers and the higher up's in the org. I learned that Mobil 1 oil out performed every readily available oil.

In addition, I had a cam/rocker failure @5000mi. in my Honda 500 Ascot thumper while using Spectro motorcycle oil. I switched to Mobil 1 15w-50 per the advice of the engineers at Mobil and rode for many years and over 30K mi. without any visually detectable wear.

I was informed that Mobil 1 retains it's high temperature viscosity far better than non synthetics (viscosity index). Apparently this is especially true for air cooled engines as they can run hotter than dino oil can tolerate. I was shown a large list of oils and the various charicteristics of each. Some oils that are generally regarded as being good oils have very poor VI and contain all manners of non desirable components, resulting in early oil failure. Castrol comes to mind as do some valvoline oils. It was clear to me that from the testing Mobil had done, the various synthetics outperformed the non synthetics by large margins, especially over time.


Hope this helps

Chris


Posted by: J.B.426---------------------

Quote:
Originally posted by DualSportr
The main reason for running a synthetic is that it lasts longer. Oil (especially in an air-cooled four stroke), shouldn't be around long enough to get into the longevity properties!

PJ


I thought we all used synthetic oil for its lubricating properties, not for its longevity. I know I don't have the frame of mind that since I'm using synthetic I can go longer between oil changes. It certainly doesn't seem that anyone else here has that idea either, at least I don't recall anyone mentioning that as a benefit to running synthetic oil.


Posted by: DualSportr---------------------

This is an excellent discussion!

In answer to Rich and others:

How we can attribute wear to Synthetic oils:
I have the wonderful luck of working for a man who is one of the best in the field of four stroke technology. This guy can look at parts and tell you why they failed (i'm learning!). The look of a cam and rocker that failed from valve float is very different from the look of a cam/rocker that failed from poor oil. Low oil has another look.

Sometimes the damage is so bad (or not bad enough!) that you can't make a determination, but in most cases, it's possible to determine the cause of a failure.

Why we think petroleum is better:
A few years ago, we did destructive testing on a bunch of engines we got cheap. They were new crate engines, all the same model. We set them up on our dyno, and turned off the cooling fans. Then we cranked up the load (we have a hydro dyno, not a drum style). In this way, we tested a bunch of different oils.

As far as we know, this is probably the best true test of how an oil will work under the worst-case scenario. In this testing, many oils failed. All of the automotive oils tested failed quickly (with an exception shown below). The synthetics also failed pretty quickly. The motorcycle oils such as Yamalube, Honda, Torco, Maxima, etc. all worked well. Also in this "middle" group was Valvoline Racing oil, 40wt (the only automotive oil that did okay). The oils that lasted the longest were the petroleum straight weight oils. Our winner? A brand called Schaeffers. Their Micron-Moly 40 wt. was the hands-down winner.

The reason the straight weight oils work better under very difficult conditions? A multi grade oil will break down to its base number - so if you're running a 10w 40, it will break down to the 10w. Not very much protection! The straight weight does not break down in the literal sense.

Why do race teams use synthetic if it's so bad?:
Because race teams have unlimited parts! Synthetic does allow an engine to rev more quickly, resulting in a tiny increase in horsepower. For the pro's, any horsepower increase is good! When you're replacing wear items after every race, and probably replacing a whole engine every couple of races, who cares if the synthetic causes a bit more wear?

As far as the automotive teams using synthetic, of course! It's not tranny fluid! A motorcycle oil does everything; valve train, tranny, clutch. Don't even think about comparing automotive testing to what we do with our small four stroke single engines.

Basically what we've found is this, if the oil is thick, it will normally protect better. It sounds too basic to be possible, but in our experience, it's true!

Some people worry about a straight-weight oil being too thick on startup. In most cases, we kick our bikes a few times before they actually fire up. If you kick your bike at least 5 times before it starts, there will be adequate oil in the head and throughout the system.

The thing is, if you've got a stock engine and you're trail riding, you can probably run whatever oil you want. If you've got a built engine (big bore, cam, stroker, etc.) or you're racing, the oil is very critical.

Like I've said, everyone has their opinion on oils. My ideas probably won't make you change your oil if you've had good luck with it over the years. I just don't want anyone to choose an oil based on incomplete information.


Posted by: Marklx---------------------

Being a newbie to this discussion, Dualsportr's analysis sounds pretty convincing. Great information and source of viewpoints. Personally, using the kawasaki lube my shop said to use, and will probably keep doing it.

Regarding the oil discussion, it seems to exist on every motor related board out there, car or otherwise, with no single "answer". People sure get one-sided on this one, but hey, whatever works.

Mark


Posted by: cujet---------------------

Nice response dualsporter.

I will have to mention that while straight weight oils do tend to protect better under extreme conditions due to the lack of VI improvers and the increased actual working viscosity. Oils such as Mobil 1 15W-50 contain no viscosity index improvers and have the natural properties of a multi viscosity rating. In addition Mobil 1 15W-50 will have higher viscosity at 350-400 degrees F than many 50 viscosity straight oils. Mobil 1 has a higher VI than most oils, VI is an excellent indication of performance.

BTW air cooled aircraft piston engines use straight viscosity oils. This is for the same reasons stated in the above posts. The straight viscosity oils tend to protect the extremely hot engine, where thiner oils wont. This is due, once again to oil viscosity, not the type of oil. Just in case you know about Mobil 1's failure in aircraft engines- keep in mind that it's lubricating properties were excellent and surpassed the conventional oils, it was not able to suspend the lead (from avgas) in the oil and the lead eventually clogged oil passages.

Chris


Posted by: Shaw520---------------------

Maintaning high viscocity in extreme heat is definatly one of the most important tasks an oil can provide. I agree with dualsport in that a straight rate oil will probaly hold it viscocity better in heat than a muti-viscocity, (thremal breakdown).
The only real reason (sales gimmic), for a multi-visc is to provide better oil flow during start-up, when engine temps are cold. IMO, this start-up period is normally low rpm and low tremp,...and probaly less stressful than at running temps at higher rpms.
Deceiving to the consumer b/c 'it looks plenty thick when ya pour it in'.
So the question remains,....does dino oil have more, or less resistance to temp viscocity break down than synthetic?


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by DualSportr
Why we think petroleum is better:
The reason the straight weight oils work better under very difficult conditions? A multi grade oil will break down to its base number - so if you're running a 10w 40, it will break down to the 10w. Not very much protection! The straight weight does not break down in the literal sense.


Over the last 20+ years there have been numerous controlled studies that would strongly argue and in most cases disprove the above statements when comparing a high viscosity straight weight versus a high viscosity synthetic oil. The concept of multigrade oil breaking down to the low temperature viscosity has taken on MYTHICAL proportions, and it's basis is RARELY scientific. I don't really expect anyone to take MY word for it (TRUST ME is NOT valid data ) , so if you guys are interested I'd be happy to post some relevant references that can be viewed at any decent engineering library.


Quote:
Originally posted by DualSportr
Why do race teams use synthetic if it's so bad?:
Because race teams have unlimited parts! Synthetic does allow an engine to rev more quickly, resulting in a tiny increase in horsepower. For the pro's, any horsepower increase is good! When you're replacing wear items after every race, and probably replacing a whole engine every couple of races, who cares if the synthetic causes a bit more wear?


Actually for most endurance type racing the value of good synthetics centers around qualities like shear strength, thermal / oxidative stability, and anti-wear. The only place you are likely to see synthetics used for their low friction properties is in normally aspirated drag racing classes.


Quote:
Originally posted by DualSportr
As far as the automotive teams using synthetic, of course! It's not tranny fluid! A motorcycle oil does everything; valve train, tranny, clutch. Don't even think about comparing automotive testing to what we do with our small four stroke single engines.


No disrespect intended PJ but you sound like a marketing guy with statements like that If the temperatures. and loads are consistent then automotive based oil testing is certainly valid for comparision purposes. To believe otherwise is fairly short-sighted. There is no reliable evidence that I've found in 25 or years of looking to support the long standing myth that motorcycle transmissions "chew up" oils, or that motorcycle specific oils have some magical properties that can prevent it from happening. It's not an accident that many OEM make NO distinction between motorcycle and automotive oil in their owners manuals. The conclusions drawn by the controlled automotive studies have consistently synced with the few motorcycle specific studies that I've seen. Powroll and Thumper seem to be the disenting voices here


Quote:
Originally posted by DualSportr

Some people worry about a straight-weight oil being too thick on startup. In most cases, we kick our bikes a few times before they actually fire up. If you kick your bike at least 5 times before it starts, there will be adequate oil in the head and throughout the system.


Given the design of current oiling systems I think you'll find that's a pretty dangerous premise to be relying on. Thick oils do not gaurantee stable viscosity at high temps, and it's not an accident that straight weight oils have been all but eliminated from most oil refiner's product lines. Pumpability at lowered temps is especially important in highly modified engines running high valve spring pressures and aggressive cam accelerations.

PJ - I don't mean this to sound disrespectful or harsh because I have the utmost respect for Powroll (bought Powroll stuff in 1973 for my CB100), but you have mostly presented empirical data with nothing other than your good word to back it up. While I'm not suggesting you are being anything but forthcoming, many of the conclusions you have drawn fly in the face of established research and years of empirical data from engine builders (myself included) in a wide variety of disciplines. While I certainly haven't built as many engines as Powroll and I'm FAR from an oil expert, I've been forced to deal with oil and heat related issues since I started turbocharging air cooled engines in the 70's. I'm not exactly a virgin when it comes to finding the limits of existing oil technology.
I realize it's probably proprietary, but the data that Powroll generated in your destructive testing could go a long way towards supporting the statements you've made.

If you can't post the data I understand, either way it's been fun having a discussion out here that allowed us to disagree like adults without anyone having a HISSY FIT, or btching about being "misquoted"

On a more personal note, any chance I can get you to send me a new Powroll sticker for my toolbox? The one I have on there pretty much gave up the ghost years ago (it must have been made from synthetic materials) LOL


Posted by: ballistic---------------------

Originally posted by DualSportr
Why do race teams use synthetic if it's so bad?:
Because race teams have unlimited parts! Synthetic does allow an engine to rev more quickly, resulting in a tiny increase in horsepower. For the pro's, any horsepower increase is good! When you're replacing wear items after every race, and probably replacing a whole engine every couple of races, who cares if the synthetic causes a bit more wear?


Ummm, circular argument Dualsportr.

>race teams have unlimited parts>
>therfore they can use oil which allows a bit more wear yet more HP> >because they have unlimited parts.

That only indicates race teams have a big budget, it does not prove whether syn. oil. is effective or not.

You make some thoughtful statements though.


Posted by: TBob---------------------

http://www.eric-gorr.com/techarticl...h_june_1999.htm


Posted by: ballistic---------------------

I just picked up a new John Deere lawnmower yesterday (6.5HP, OHV).
The thing cost almost as much as a dirtbike
Any reason NOT to run Mobil1 syn. in it once its broken in?


Posted by: DualSportr---------------------

Quote:
If the temperatures. and loads are consistent then automotive based oil testing is certainly valid for comparision purposes.


I don't think so. If this were true, then we'd run automotive oils in our car tranny. Since we don't, it's understood that a tranny has different reqirements.

A clutch DOES put oil through the wringer - literally. The increased heat and friction from a clutch puts more crud in the oil and heats it up more than an automotive engine can.

The reason this is difficult to test is that most testers use a dynojet drum-style dyno to do testing. The drum dyno isn't very good at simulating real-world stresses on a clutch/tranny. Using a load dyno you can see more of a realistic test condition, but it's still not the same as what we do when we're flogging the clutch on a nasty hillclimb.

I'm not a big fan of the oil test data that's out there. Why not? because there's test data showing what I believe, and there's also data showing the complete opposite.

Also, none of the major tests are utilizing a single-cylinder ohv air cooled engine as a test vehicle. If they say they've tested motorcycles, check to see which ones -- the typical testers are a Honda Goldwing and a Harley Davidson - both of which have their tranny separate.

What I really wish is that Motorcycle Consumer News would do an oil test on dirt bikes like they did for street bikes. That would be as unbiased as possible, and the data would be reliable.

Of course, now that the CRF450 is out there -- we'll have a whole new engine to test our theories on! It's cool to see a modern design utilizing the separation of the clutch fluid from the valve train. The BSA single used it years ago, and had good luck (of course, the Lucas electrics did 'em in before the tranny ever got any wear on it!).

In theory, this design should allow much more clutch abuse without oil failure or wear to the head/tranny. I really can't wait to get my hands on one of those engines!! Oh yea, and I'd like to ride it too!


Posted by: DualSportr---------------------

Quote:
On a more personal note, any chance I can get you to send me a new Powroll sticker for my toolbox?


Yea, we've still got the "running engine" style of stickies, if you want 'em, just e-mail me at work

mail@powroll.com

Give me an address, and i'll happily send you a couple!


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by DualSportr


I don't think so. If this were true, then we'd run automotive oils in our car tranny. Since we don't, it's understood that a tranny has different reqirements.


That's specious logic at best my friend

Quote:
Originally posted by DualSportr

A clutch DOES put oil through the wringer - literally. The increased heat and friction from a clutch puts more crud in the oil and heats it up more than an automotive engine can.


In most cases I would agree.

Quote:
Originally posted by DualSportr

The reason this is difficult to test is that most testers use a dynojet drum-style dyno to do testing. The drum dyno isn't very good at simulating real-world stresses on a clutch/tranny. Using a load dyno you can see more of a realistic test condition, but it's still not the same as what we do when we're flogging the clutch on a nasty hillclimb.


I've never seen published research paper that used a Dynojet device. That seems to be the domain of the half-ased dirtbike press.

Quote:
Originally posted by DualSportr

I'm not a big fan of the oil test data that's out there. Why not? because there's test data showing what I believe, and there's also data showing the complete opposite.


I'm not sure what data you are following, but the SAE and I Mech E data is pretty consistent. I would agree that lots of crap gets passed off as real data.

Quote:
Originally posted by DualSportr

Also, none of the major tests are utilizing a single-cylinder ohv air cooled engine as a test vehicle



You just need to widen your scope The only papers I have directly at hand are :

SAE 750789 - Four stroke motorcycle engines, a study of their lubricating oil requirements.
(1975 real aircooled motorcycles from 125cc to 900cc MX, RR and street)

Lubrication of Small Engines - I Mech E C160/78
(A general paper using air cooled motorcycles engines but no Harleys or Wings )

Lubrizol has a wealth of valuable published research on the lubrication requirements of motorcycle engines of all types . There are more but my filing system is more of (as Gordon Jennings would put it) "a Technocrat's Library strewn about in my house" . I've NEVER seen a real peer reviewed oil research paper that used a Harley or a Gold Wing engine. Maybe I just haven't been paying attention.


Posted by: DualSportr---------------------

Quote:
Lubrication of Small Engines - I Mech E C160/78


I'd reallly like to see this one! When was it written?

The tests I was talking about which used the Goldwing and Harley engines were those done by Mobil 1, Syntec, and a few other oil companies to support their use as motorcycle oils.

I do agree that my knowledge is more empirical than scientific. I really should get my boss to discuss this with you -- he has both, in spades!


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by DualSportr
I'd reallly like to see this one! When was it written?


It's a paper that was presented at the 1978 Isle of Man Conference of the Institute of Mechanical Engineers. You can probably get the paper as a reprint directly from I Mech E, or you can find it in the conference papers publication "The Design and Development of Small Internal Combustion Engines" ISBN # 0 85298 394 8


Posted by: bwalker---------------------

Quote:
I don't think so. If this were true, then we'd run automotive oils in our car tranny. Since we don't, it's understood that a tranny has different reqirements.

Allison specs a diesel motor oil be used in ther transmissions when they are used for high temp high load service. Food for thought.


Posted by: 07---------------------

To look at this from a slightly different angle, whats the downside in using a semi synth. All seem to agree that these are fine, so why bother with fully synth?


Posted by: Shaw520---------------------

Quote:
Originally posted by 07
, so why bother with fully synth?

B/C it offers the best wear protection on metal to metal contacts in the engine, (longevity with limited wear)..... but the claims are that it may be too good for the clutches, that rely on an amount of friction.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by 07
To look at this from a slightly different angle, whats the downside in using a semi synth. All seem to agree that these are fine, so why bother with fully synth?


I don't think ALL agree that semi-synthetics are as you put it "fine". Semi-synthetic is a pretty generic term that potentially covers a lot of good oils, as well as a lot of piss-poor cost reduced oils.


Posted by: 07---------------------

Quote:
Originally posted by Rich Rohrich


I don't think ALL agree that semi-synthetics are as you put it "fine". Semi-synthetic is a pretty generic term that potentially covers a lot of good oils, as well as a lot of piss-poor cost reduced oils.


O.k let me expand that a little. Assuming we are talking about a a good quality semi synth, what disadvantage would it have over a good quality fully synth. It's not as if we are talking about trying to get 10,000 miles out of our couple of pints, most people here change the oil every few rides.


Posted by: Shaw520---------------------

07, There is a degree of wear occuring weather you put 10 miles on an oil change or 10,000, and the demand of new generation four strokes, ( higher compression, increased rpm, increased valve spring rates/cam pressure, increased temps) the list goes on, all on a single quart of oil.


Posted by: 07---------------------

Quote:
Originally posted by Shaw520
07, weather you put 10 miles on an oil change or 10,000, when the engine is running, there is a degree of wear occuring, and the demand of new generation four stroke, ( higher compression, increased rpm, increased valve spring rates/cam pressure, increased temps) the list goes on, all on a single quart of oil.


Which is why we change it more often than a normal engine. What I am asking is if you choose to use a good quality semi synth, what are the possible pitfalls. I just don't buy that any significant increase in wear will occurfrom semi synth if the oil is changed every 200 miles or so. Reading some of the posts, it seems that the fully synth 'may' cause more problems.

I'm not offering opinion, I've no feelings either way (so long as it's not GTX eh Rich!), I was merely asking. :confused:


Posted by: Shaw520---------------------

Quote:
Originally posted by 07

I've no feelings either way

Then put in what ever oil you feel is best.


Posted by: ted jackson---------------------

the mobil1 site has info that explains the differences between the auto and motorcycle oils, and their various motorcycle products. Sounds like a difference in additives like phosphorous and the detergent.
sorry, I couldn't make this a hyperlink.
http://www.mobil1mcoil.com/qa.htm


Posted by: jackie g---------------------

so there is no other way to ask this question but just to come out and ask it. will mobile one hurt my yz250f over a period of time. or is everone being a little paranoid over the debate between dino oil vs. synthetic. automotive oil vs. motocycle oil. i just want an informed opinion if my bike will be ok using mobile one which is nearly $4 cheaper than yamalube that i am no using. thanks for any opinions.


Posted by: atk_man---------------------

If I changed my oil every 3-5 hours I would be very poor! I ride 3-5 hours every day, my bike holds almost 4 liters. Since I have a speedo, I change the oil every 2000 km. That has worked fine for 3 years now. By the way, I'm running klotz 20w50 full synthetic.


Posted by: Kawierider---------------------

hey guys,

i was talking to and engineer at ford about motor oil. I don not remember what brand of oil he was using but, he gave me proof that synthetics protect engines better from wear than petroleum, products. He told me a story about when he was testing a new hi-po motor in a mustang. they ran the mustang for 15,000 miles. The engine showed low compression after some testing. concerned, they pulled the heads off looking for a blown gasket. to their surprise the cylinder walls still contained the cross-hatch pattern on them. The engineer for the oil company told them not to use synthetics to break the engines in. It lubricates too well and the motor will not wear enough to seat the rings. sooo, for those of you with four-strokes that have the seperate tranny and transmission oils( i know there arent alot) you might want to try the synthetic stuff.
Tim


Posted by: DougRoost---------------------

There's no doubt that in automotive applications full synthetics are unbeatable (the issue with our thumpers is of course it may be too slippery for the clutch). I saw a fantastic test result on a BWM straight 6 engine that ran Mobil 1 (after break-in so the rings were seated). They ran this engine non-stop on a dyno for the equivalent of over 200,000 miles then tore it down. Looked brand new - even the cam lobes! So they bolted it back together using only new gaskets and ran it for over 800,000 more miles (much of this was in a car as I recall)!

As a guy who restores cars as a hobby and is getting back into dirtbikes after too long off, will someone (Rich?) please tell me WHY 4 stroke dirt bikes share the engine and transmission oils?! Especially with a wet clutch setup. This makes no sense to me but there has to be a good reason. Then again, Honda seems to have come to the same conclusion with the CR450F, though I'm surprised KTM didn't first with their RFS's. And it isn't weight since that was one reason Honda separated separated the sumps on the CR450F.:think


Posted by: 07---------------------

Quote:
Originally posted by atk_man
If I changed my oil every 3-5 hours I would be very poor! I ride 3-5 hours every day,


Lets not forget we all ride different engines in a different way. I ride an R1 on the road, change the oil every 2000 miles, no problems. I also ride a YZ426F on the road, I change the oil every 500 miles (thats a guess - no speedo), yet my sons dirt bikes I change it every other meeting as he's pushing it to its limits.

With respect, your 3 - 5 hours is hardly likely to be as demanding as 3 - 5 hours on a track, so I fail to see the comparison.

Anyway, I've just changed the YZ oil. Castrol GPS that'll do !


Posted by: Max Factor---------------------

Quote:
Originally posted by DougRoost
WHY 4 stroke dirt bikes share the engine and transmission oils?! Especially with a wet clutch setup. This makes no sense to me but there has to be a good reason. Then again, Honda seems to have come to the same conclusion with the CR450F, though I'm surprised KTM didn't first with their RFS's. And it isn't weight since that was one reason Honda separated separated the sumps on the CR450F.:think


Cannodale beat them both


Posted by: 07---------------------

Quote:
Originally posted by Max Factor


Cannodale beat them both


"It's cool to see a modern design utilizing the separation of the clutch fluid from the valve train. The BSA single used it years ago"

Beat Cannondale by .......30 years?


Posted by: DualSportr---------------------

Yea, every time I get excited about something "new" and "different", my boss just yawns and shows me a picture of something from the 'teens or the 'twenties that already did it!

He says that's the reason he never gets excited about anything, it's all old to him -- the only things that change are the metallurgy and fit and finish!


Posted by: Rich Rohrich---------------------

The farther back you can look, the farther forward you are
likely to see.

~ Winston Churchill ~




Posted by: DougRoost---------------------

"Those who don't know history are doomed to repeat it."


Posted by: J_dem_Bones---------------------

I have been using Castrol Syntec blend with no noticable damage or wear yet. :silly: Now I noticed no one even mentioned it!
Should I change the oil type when I do the next oil change?

Also I have a oil level question:
Do you check the oil level while its cold? Or after it has been started?
I checked my level when it was cold, and couldn't see it on the dip stick so I added some more oil. After adding some more I still couldn't see any. So I started the bike and after I turned it off, the level was half way up the whole stick!!(not the level gauge section on the tip)
thanks :confused:
I have a "00" YZ426F


Posted by: DualSportr---------------------

Rich, I'll leave the Syntec question up to you!!!

As far as oil measurements go, you should check it when the engine is warm. A dry sump engine will read completely incorrectly if the engine is cold.
Also, it's important to follow manufacturers instructions for filling the oil -- i don't know what type of bike you have, but you need to read your owners manual to make sure you're doing it right.

Another thing that some people don't know, don't screw the dipstick in to check the oil. Just drop it in the hole until it seats, then pull it back out to check the level.


Posted by: J.B.426---------------------

J_dem_Bones,
DualSportr is right about checking the oil. For the 426 you need to start the bike and let it run for a minute or two. Shut it off, pull the dipstick, wipe it, put it back in until it stops, do not thread it in, and pull it out and check it. It should be between the marks. You'll never get a reading if you try to check it cold. By the way, it holds between 1.6 and about 1.8 quarts, depending on if you change, or clean, the oil filter.


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by DualSportr
Rich, I'll leave the Syntec question up to you!!!


I've never used it and have never found a compelling reason to start . Sorry


Posted by: OldManIn---------------------

Has anyone taken into account that car engines and harley-davidson motorcycles have the transmission separated from the engine? Using a synthetic in the engine will not adversely affect the clutch. The number one reason stated for not putting synthetic oil in your thumper is clutch slippage. Cars (and Harley's) don't have this problem, they have different transmission fluid (mineral based).

Ballistic's statements that all these high-performance engines use synthetics is not valid, they use a different oil in the transmission.

------------------------------------

I just read backwards on this thread and I see that a few of you in fact did address this. I'm afraid that to many out there still have not put it together. The valve-cam-rocker etc. all love the synthetics. Transmissions (clutches) hate it. Most thumpers share oil between these systems and thus you have to go to the lowest common denominator, the transmission. The new Honda CR450F went to separate systems to get around this. Most other have not.


Posted by: JasonJ---------------------

Well the WR manual DID say NOT to use oil with certain grading ABOVE what was listed. (Sorry, dont have the book in front of me) Because it was bad for the clutch. My first time using full synth oil was in a VFR 750 wet sump street bike. Guesse what, the clutch slipped in 4th 5th and 6th gear. I replaced the clutches, refilled with synth, and it slipped agian in 5th when you rolled on hard in the tripple digits on the spedo. I glazed 2 brand new clutch disks. I replaced the burnt plates and refilled with GTX and was good to go again. The VFR was putting out over 100 ponies, and I agree that I dont think the WR clutch is seeing that kind of torque on a regular basis, but then agian I never climbed hills with the VFR. This is why I dont use the synth oil when it has to wet the clutch. The clutch is by definition a friction device, and the full synth oil by definition is supposed to greatly reduce friction. The clutch will win, it is just a matter of heating the oil utill the clutch grabs. I am with the plain Castrol GTX group, especially if I am going to be dumping the oil every 5 to 10 hours of hard trail riding. I could tell when it was time to change the oil in the VFR cause it would shift hard. Long oil life is not the point here though, long motor life is. As oftern as the oil is going to be changed Im going with what Yamaha and pepole who rip these things apart when they go BANG, are saying.


Posted by: Squidwannabe---------------------

Synthetic oils aren't bad for your bike,with age of the motor they'll just seep past the rings and valve guides and burn off quicker.

Don't believe it ? Try for yourself, then try with Bardahl oil. I think Bardahl oils are thicker and have a higher flash point and less oil will burn off.

If you change your oil every 1000miles, I don't think you see a huge difference in engine life compared to synthetics. IMHO .


Posted by: DualSportr---------------------

Quote:
If you change your oil every 1000miles


Hopefully more often than that for a dirt bike.


Posted by: Squidwannabe---------------------

Quote:
Originally posted by DualSportr


Hopefully more often than that for a dirt bike.


Right , sorry. I ride a dual sport so I tend to forget ...


Posted by: J_dem_Bones---------------------

I know not to thread in the dip stick, but I didn't know if I should warm it up or not... Thanks alot for the answers. :D


Quote:
Originally posted by Rich Rohrich


I've never used it and have never found a compelling reason to start . Sorry


Which oil would you recomend? Would switching back now hurt it?
I havn't had any problems with the clutch, but then again I don't use it too much....


Posted by: weimedog---------------------

Well I've been using Mobil One 15w50 in my VOR since March. I change it after every two rides. No clutch problems yet. I doubt the VOR has any better a clutch arraingement than any other brand and I KNOW those 503 VOR's make some good torque. Conclusion? Mobil One 15w50 doesn't hurt VOR clutches. I have a lot of hard hours on that bike now. If things were going to fail, I would see the signs by now. Nothing has other than crash damage. One of the Enduro's was the Peetz Table with lots of clutch slipping tight stuff. Not even clutch material on the magnetic plug after that one. Think this clutch is going to last a while. With Mobil One. I love imperical data.

( Paralysis by analysis? ...I also use Castrol GTX in my old Husqvarna..cause its cheap and that old monster hold almost two quarts. I change it after every three rides.)


Posted by: DualSportr---------------------

Quote:
I havn't had any problems with the clutch, but then again I don't use it too much....


That's okay, bent shift forks are cheaper than clutch plates. Just harder to get to!:confused:


Posted by: J_dem_Bones---------------------

Quote:
Originally posted by DualSportr


That's okay, bent shift forks are cheaper than clutch plates. Just harder to get to!:confused:

Those can bend from rolling on the throttle out of a corner?:scream:
That's what I meant.


Posted by: DualSportr---------------------

If you're shifting without using the clutch, you can bend shift forks (some riders are very good at shifting without the clutch, and don't do much damage).

No other non-use of the clutch will cause damage, unless you're lugging it (can break gears) or over revving it (rod failure or cam chain failure).


Posted by: DougRoost---------------------

In the Motocross and Offroad Riding Techniques book, Gary Semics says to never use the clutch when downshifting. Says unlike upshifting, there's no load on the gears so using the clutch when downshifting just costs time. Seems to be true in my experience as well. <<2 strokes only -- use the clutch on 4 strokes!>>


Posted by: KDXDan---------------------

My son rides a TTR-90 every day. When I bought it they told me I could use any motorcycle or automotive oil as long as I changed it frequently. Is this true. I have been running Havoline in it but I change it almost every week. Should I switch this bike to motorcycle oil? Thanks.


Posted by: DualSportr---------------------

Quote:
Should I switch this bike to motorcycle oil? Thanks.


Since you're changing it so often, the only thing I would do is switch to Valvoline Racing oil. It's still cheap, and it actually works well.


Posted by: DualSportr---------------------

Quote:
never use the clutch when downshifting. Says unlike upshifting, there's no load on the gears so using the clutch when downshifting just costs time


He's referring to a two stroke. Big bore four strokes put quite a load on the engine when downshifting.


Posted by: DougRoost---------------------

You're right and I guess I did know that. Engine braking is a great thing on the trails but by definition it has to load the transmission to work!


Posted by: DualSportr---------------------




Posted by: J_dem_Bones---------------------

Hey Dualsportr,
Which oil do you use? And if I were to switch, would there be any problems?


Posted by: Marklx---------------------

Anyone using Castrol Actevo (i believe a 50/50 blend) in their 4-stroker. Heard it is good, has the right stuff for clutch issues, etc etc.

Mark


Posted by: CraigW---------------------

Just some interesting facts about Oil viscosities.
These are taken from Castrol's product handbook for South Africa (grade names may not be exactly the same as those in other countries)

Full synthetics-automotive
Formula SLX(0W/30) viscosity @ 100 degC=11.9mm^2/s
Formula RS (10W/60) viscosity @ 100degC=24.8mm^2/s
Full synthetic -motorcycle
RS Superbike(5W/40) viscosity @100degC=13mm^2/s
Semi synthetic-motorcycle
Actevo(10W/40) viscosity @100degC=15mm^2/s

Mineral - automotive
GTX (20W/50) viscosity @100degC=16.75mm^2/s
XL40(SAE40) viscosity @100degC=13.5mm^2/s

The above numbers make it clear that there is no relationship whatsoever between the viscosity @ 100degC(an approximate operating range of most engines) and the 'W' number of an oil. In fact this number is used to express the oil's ability to perform (its flow characteristics)at very low temperatures ,during start up conditions.

Making reference to another subject mentioned earlier regarding automotive oils being used in gearboxes, this too is fairly common - Landrover and Isuzu being just 2 of many who make this specification.:think


Posted by: MikeT---------------------

Quote:
Originally posted by Rich Rohrich


The day I start taking oil advice (or ANY technical advice) from THOSE tehno-impaired nitwits, will be the SAME day that pigs fly over my house while I'm standing in the yard holding TWO winning lottery tickets and watching Gomer work on MY bike. :scream:


That just kills me Rich!!! Truly FUNNY!!


Posted by: DualSportr---------------------

Quote:
Hey Dualsportr, Which oil do you use? And if I were to switch, would there be any problems?


I use a brand called Schaeffer, their micron-moly racing oil works for me. Powroll sells it under their label (straight 40wt and a multi grade, I use the straight wt), or you can get it from a Schaeffer dealer. They sell to truck companies.

I've also used, and had good luck with, Torco. I believe they make a very good product, which has held up well in testing.

If you switch from a synthetic to a non synth or semi synth, make sure you flush the system out completely. This isn't easy to do with a dry sump bike and can be a major hassle.

For the YZF models, because they use a shim/bucket design on the valve/cam wear areas, they seem to do very well with branded motorcycle synthetic oils such as the Yamalube, Torco, Maxima, etc.

What was determined after testing was that cheap oils were cheap for a reason in most cases, they didn't hold up as well as the more expensive "motorcycle" oils.

Like I stated before (read previous posts in this thread), everyone has their own favorite. I've been lucky enough to see how oil works in LOTS of different engines, I'm giving you my opinion based on ALL of this evidence, not just what has worked for me personally.

If you want to run a cheaper oil, there's only one that we found worked okay, that was Valvoline Racing oil. It's not good for very heavy load conditions (like racing), but if you're an intermediate rider in less than harsh conditions, it's okay. You'll have to change it after every ride though.

My take on the deal? Even if I'm spending $20 a month on oil, it's cheap insurance. Four strokes are VERY expensive to fix when they break.


Posted by: J_dem_Bones---------------------

I've used the Castrol syntec for 6 months and change it every 4-5 rides. I do ride it pretty hard and it's hot here in Lake Elsinore where I ride. Now I haven't noticed anything becoming from using Castrol, but I want to run whats best and will save my bike. I did notice a little oil burn, not as much as my street bike(FZR600). It still showed on the dip stick ....


How would I go about flushing my oil? Like as what to use and the procedure.?.?.

I'm very new to 4-strokes. I've been a 2-stroker all my life untill I rode the YZ426f......hehe thanks for your patients and help!!


Posted by: DualSportr---------------------

Quote:
How would I go about flushing my oil? Like as what to use and the procedure.?.?.


Oil on the dry sump bikes, like your YZF, is housed in all sorts of nooks and crannies. The trick is to get the synth out completely so it doesn't argue with the petro.

First, drain the oil from the engine and frame. Leaving the engine drain plug out (nope, not kidding here!), add some cheap petro, like the Valvoline Racing oil (you can buy it at walmart). Add only 1/4 a quart or so.

Now kick the bike -- basically what we're doing is the same thing as you do when you bleed your brake lines. We want to flush the new oil through the system, push out the old stuff, but not pump air thru the system.

Kick the bike until start to see the new oil mixed in with the old stuff. Put the drain plug back in and fill the bike according to mfr's suggestions using the Valvoline racing stuff. Start it and ride it 10 minutes or so. Do not ride up hills or put a load on the clutch.

Drain that oil, and put in the stuff you plan to use from now on.

The reason I go through this major hassle if switching between synth and petro is because these new four strokes hide so much oil in the system, and the two oils don't seem to like each other very much.

I've seen glazed clutch plates and other wierd problems from switching without going thru all the steps outlined above.

Note that you can switch between brands without problems, but not between petro and synth.


Posted by: J_dem_Bones---------------------

thanks alot!!
It actually doesn't seem like too much, just a little time and extra money($15 for the whole process).:D


Posted by: Sage---------------------

Oh Boy, I told myself that I'd never post in a oil topic, but I saw the race team thing and had to drop my.02, I know this is road race experience but to put it into dirt bike form i guess there will need to be some math. 750 suberbike @161 hp, 68ftpds torque, divide by 4 and we have a 187.5cc single that would make 40.25hp and 17ftpds of torque, power range starts at 7800rpms and peaks at 12,800 with a over rev to 14,000 limiter at 15,000. I think that we can all agree that this would be one rippin little 187 four stroke right? well the cams lasted more than 2 season, the plain bearings lasted most of the season, the trannys and gear drive on the cams would last all season, all engines cam apart every 500 miles and most all parts were reused except gaskets and a qusetionable bearing or ring. the engines were broke in on a load dyno with a non synthic and after break-in were always ran with a 0-30 100% synthic, yes 0-30. there the wrench in the gears for this topic, if you still think that theres not enough load to justify this post try holding a engine wide open for 200 miles around daytona, the data shows that 1 lap around daytona has 1min 15sec of 100% throttle, so to say that thin oil wont hold up in the real world is a old school method of thinking.

Also we had a dyno jet model 200 non-load dyno and a large load dyno, both would show within 1 hp of each other. the main need for a load dyno is for r&d and product development, a inertia dyno is great for tuning, not so good for r&d.

PS. whats up squid!


Posted by: RYDMOTO---------------------

From what I have read,what seperates a true motorcycle oil from car oil is the addtion of polymers to the motorcycle oil for the reason of the transmission teeth and other forces in the transmission.Mibile one 15w50 added to a car transmission using the logic on some of these posts should work rather well.We know the answere here,don't we.On the other hand,car trans oil used for dirtbikes,lessen the longevity of the engine.For me......i have always used honda hp trans oil.Never had a single problem.Clutches have lasted forever too.Just my two cents here.......maybe it can spur further thoughts.I really like thsi site. : )


Posted by: OZ_dirtrider---------------------

Man what a post....

I've had a 93 CBR900 for 50'000 kms of it's life, used Motul 5100, Mobil 4t, Maxima etc etc. road k's are about 30'000 kms and 20'000kms of racing which the bike hardly every seen below 6'000rpm and spent a lot of time at 9-12'500 rpms.
I've had two stroker's and now a 4st dirt bike - ride them as hard as l rode on the race track.
My argument.... preventative maintenance.
I've stripped (took it to a well known race tuner) the Blade after 45'000 kms and the engine wear was very minimal considering the age of the bike (slight wear of the 1 and 3 gears and camshaft gear) and really all l did were the shims and cam chain - it probably would have lasted another 50'000 kms.
All l do on every bike is lube the top of the head properly, couple of starts with the kill switch on or about 5 kicks and change the oil frequently - after a race meet, change the oil/filter; after 8hrs of bush riding, change the oil/filter.
I really don't think what type of oil you use so long as you change regularly and don't get lazy about the silly notion that adding in new oil before riding and then not changing the oil until, say 500kms, will help protect the motor for that 500kms could either equate to 500kms of soft riding or 500kms of hard riding.

J
:silly:


Posted by: Rich Rohrich---------------------

Quote:
Originally posted by RYDMOTO
From what I have read,what seperates a true motorcycle oil from car oil is the addtion of polymers to the motorcycle oil for the reason of the transmission teeth and other forces in the transmission.


Sorry but that's a MYTH.


Posted by: swamper---------------------

Regarding the shearing forces of motorcycle transmissions, have you seen how the oil pump in your car engine works? Or the cam chain? Or the distributor drive? Now the clutch on the other hand represents some other issues, probably the most significant of which is contamination.


Posted by: Sage---------------------

Or how about the tranny in some cars, most newer ford sticks want atf in them?? Oh Yea, the goldwing also uses the same oil for the engine & trannsmission, unlike the H.D. mentioned before


Posted by: RYDMOTO---------------------

http://brickboard.com/FAQ/700-900/E...:%20Lubrication this is a rather informative article on synthetic oils.Its has to do with cars,but I found it very interesting.Castrol syntec is NOT a true synthetic as I found out here.Wish I knew how to do the click on this thingy......sorry about that!


Posted by: weimedog---------------------

To the posting from Sage about ATF:

I can't even imagin putting ATF in a four stroke where oil is shared with the motor and the transmission! So why is this ATF thing even showing up here? Isn't this about 4-Strokes and Synthetics? :think

One thing Automotive Manual transmissions have that Dirt bike transmissions don't are syncronizers. That is also one of the many reasons automotive companies have toyed with ATF in manual transmissions. Syncros tend to keep the engagement from gear to gear from being so abrupt. Therefore comparing Automotive Syncro gear boxes with dirt bike crash boxes isn't really valid in my mind. Since syncros are like little clutches and they tend to wear out faster the bearings and gears...there is a thread of logic with that concept. Also the lighter viscosity tends to eat up less energy when being pumped around. Back when fuel milage was a bigger issue they pushed in that ATF direction from time to time. Probably will again as the price of fuel is getting so high were fuel milage can be a marketing advantage.

I never have seen any company ever recommend a ATF in a hi-torque application non-syncro transmission. The lightest viscosity recommendation I have seen with crash boxes is with motorcycles and the trans-hydraulic in some farm tractors.

But this thread is about FOUR STROKES!! So..:scream:

.....

I still use Mobil 1 15w-50 in My VOR....No problems yet. The drain plugs with the magnets come out clean now that things are broke in. I still don't think that VOR clutch is any better than any other brand out there so if works with mine its got to be ok with others.


Posted by: RYDMOTO---------------------

http://brickboard.com/FAQ/700-900/F...cantData1.shtml i re-pasted the site......last one was not comeplete.


Posted by: J_dem_Bones---------------------

Ok. Someone had to restart this post after 2 months on the self.
If I understood all the talk. It's the clutch of a 4 stroke dirt bike that breaks down the oil. The use and abuse of a dirt bike clutch couldn't be compaired to a car or a street bike! Then it uses it for the transmission.
I know my R6 doesn't abuse it's clutch like any of my dirt bikes. I know my yz426f doesn't use the clutch like a yz250 2 stroke, but it is used ten folds more than my R6 or Truck!



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