SUMPOLOGY - Secret World of 4 Stroke Oil



4 replies to this topic
  • Dwight_Rudder

Posted January 09, 2004 - 12:51 AM

#1

Nice feature article from Motocross Action Magazine for this month. I can't really disagree with anything they say. This long but I think worth while for me to type.
This is not the start of a argument but take it for what it is worth. This comes from the motorcycle industry but NOT an oil company. They are not recommending specific brands of oil . Neither do I .
There is no need for descussion here. Use what you want. I just thought it was a nice article and wanted to share it. There is a UMPTEENTH line discussion going on elsewhere in the forum .
Cher'o,
DWIGHT RUDDER
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Sumpology
--------------
Secret World of Four-Stroke Oil
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There's more to it than car oil
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The life blood of a four-stroke engine is motor oil. It breathes it, eats it and oozes it. Most four strokes, save the CRF450 and CRF250, use the same oil to lubricate the valves, cam, piston, crank, clutch, and transmission. This shared oil forces the motor oil to lubricate more than double the moving parts as the independent premix and gearbox of a two-stroke.
In an effort to reduce weight , maximaize power and trim the cases , your light-weight four-stroke motorcross engine uses just enough oil to get hte job done. On a racing machine , it's more important than ever to use the best racing oil made and to change it rutinely.
Q:
IS AUTOMOTIVE MOTOR OIL BAD FOR A MOTORCYCLE ?
A:
Not bad, but probably not the best. Why not ? It is designed in reverse order to a motorcycle oil. The priority hierarchy of automotive oil is :
( 1) Maximize fuel economy .
( 2) Reduce emissions.
( 3) Offer protection for the moving parts.
Today's automotive motor oils do not have the same degree of extreme pressure and anti-wear agents that they did just a decade ago.
Q:
WHEN WAS AUTOMOTIVE OIL AT ITS BEST ?
A:
Oil changed ten years ago when automakers were pressured to clean up the air. Since 1993, the entire automotive industry has worked to reduce exhaust emissions. Automotive motor oil must adhere to the performance categoies set by the American Petroleum Institute ( API ) .
These are called the API service categories. The API categories have been around for 50 years, but for the first 35, the categories were upgraded six times to meet the demand for higher engine performance.
The current API designation is SL. The API SL oils are designed to provide better high deperature deposit control and lower oil consumption. SL oils are missing important agents that improve extreme use lubrication. In their place are friction modifiers that improve fuel economy.
Q:
WILL AUTOMOTIVE MOTOR OIL HURT MY BIKE ?
A:
It could. If you're using and automotive motor oil in your racing four-stroke , you're not buying the best protection. An API SL oil is missing vital anti-wear components:
The most important being Zinc, Phosphorus, and Sulfur. These agents are harmful to the catalyst tha is used to diminish the level of pollutants in automobile exhaust.
Q:
WILL AUTOMOTIVE OIL HURT MY CLUTCH ?
A:
YES ! The friction modifiers in motor oil improve fuel economy by making it easier for the gears , bearings, pistons and rings to slip , slide and turn inside the engine. Unfortunately, these friction-minimizing agents also make it easier for the clutch in a motorcycle to slip. If you are using automotive motor oil in your bike , apart from CRF's, you are losing hook-up and acceleration, as well as reducing the life of the clutch.
Q:
WHY SHOULD I MEMORIZE THE ACRONYM " JASO" ?
A:
As soon as it became apparent the the American Government was mandating economy over protection, the Japanese Automotive Standard Organization ( JASO ) developed a standard specifically for performance four-stroke motocycles. JASO designates two different four-stroke oil classifications:
MA and MB.
The MB il is low friction and the MA is sans the friction enhancers ( ie. Honda synthetic silver and gold )
Q:
WHY ARE MOTORCYCLE -SPECIFIC OILS BETTER ?
A:
Motorcycle specific oils are pumped up with five times the anti-wear , anti-scuff and extreme pressure additives of regular motor oil. As an added plus, motorcycle oil does not include ( except for MB rated Honda Silver ), molybdenum disulfide and other friction modifiers that wreak havoc on clutch performance.
Maxima, a popular motorcycle oil supplier, starts with a API SG Service Category base oil, the last formulation that was't regulated as to the amount of Zincdialkyldithiophosphate ( zinc, phosphorus, and sulfur ) it could contain. Maxima then boosts protection through a proprietary mix of performance additives. The end result is a motorcycle oil that doesn't break down under extreme heat and is tough enough to cushion meshing gears.
Q:
WHICH FOUR-STROKE RACING OIL SHOULD I USE ?
A:
If the bottle of oil doesn't list that it is an API SG Service Category or JASO MA spec, it's not good enough for your motocross bike. Although a bottle of oil might say "motorcycle specific" or "safe in wet clutches," the best endorsement is the API SG or JASO MA designation. It's better to be safe than sorry.
There is a caveat that applies to CRF owners, however --whic we will clear up in a few paragraphs.
Q:
WHAT VISCOSITY SHOULD I USE ?
A:
The most popular viscosity is 10W40. It's thin enough not to bog down the crank and offers ultimate protection uder an extreme lad. Every owner's manual lists the recommended oils, brands and viscosities.
Q:
HOW IS A CRF LIKE A CAR ?
A:
The Honda CRF oil system separates the combustion side of the engine from the transmission. The CRF separates the engine sump to keep the metal shavings from the transmission from floating around in the same oil that is use to lubricate the piston , rings, and rod and crank bearings.
The upside of this design is that the CRF can use a slipperier JASO MB - spec oil in the top-end, while using a JASO MA-spec oil in the transmission.
Q:
WHAT ABOUT THE CRF TRANSMISSION ?
A:
Do not use automotive motor or gear oil in the CRF transmission. It the gear oil doesn't have the word "two-stroke gear oil ", safe to use in wet clutches, Or the API SG or JASO MA designation, don't use it.
Q:
IS IT BETTER TO SEPARATE THE ENGINE AND TRANSMISSION OIL ?
A:
Yes and no.
Honda uses separate oil for the CRF's top-end and transmission. This is not a new idea. BSA did it decades ago. Yamaha , Kawasaki, KTM, and Suzuki use the same oil in the top-end and tranny.
Which is better ?
Separate oil:
The benefit of separating the oil, like Honda does , is that the top-end is not contaminated by clutch debris or broken teeth. Additionally, hte heat of the combustion side doesn't thin out the transmission and clutch oil. The CRF can use an MA-series oil in the tranny and slippery MB-series oil in the top-end.
The downside is that the oil quantity in each chamber is reduced ( to approx. 650cc ),
increasing the need for more frequent oil changes. Any oil loss , no matter how small, becomes critical when you have a small pool to draw from.
Shared oil:
The benefits of using the same oil throughout the engine, like the RM-Z, KX-F, KTM, and YZ-F, are that the lare supply is less likely to reach critical levels, overall engine temperatures are reduced and oil changes aren't demanded as frequently. On the downside , shared oil engines must use an MA-series oil for the clutch ( which means that the top-end doesn't get the benefits fo the slippery MB friction modifiers ).
Q:
WET SUMP, DRY SUMP OR SEMI-DRY SUMP ?
A:
Don't get to confused by these terms.
by definition they are different, but in action they all work about the same.
A wet sump engine has a pool of oil in th ecrankcase. A dry sump engine doesn't store oil in the crankcase , but instead in a remote tank and oil lines. A semi-dry sump engine is , in reality , just a marketing term for a wet sump engine that tries to elevate the cranshaft out of the pool of oil .
The Yamaha YZ-F is a dry sump design. All other four-strokes use wet sumps, although they go to great lengths to avoid the negatives of an old-school oil pan under the engine. Suzuki and Kawasaki coined the semi-dry sump termenology, but the KX-F and RM-Z are at the very least semi-wet sump engines.
Q:
CAN OIL MAKE MORE HORSEPOWER ?
A:
YES.
Special blends of low viscosity ESTER SYNTHETICS cna protect like a 30W under extreme use, but let the crank spin like it has a 0W. Zero weight is the same viscosity as water.
But, the real secret to getting horsepower out of four-stroke oil is to use less of it.
Most modern four-stroke engine designers try to keep the crank ( and even the transmission gears) from beign submerged in an oil bath. It takes horsepower to slog thes parts though heavy oil. Thus, lessening the amount of oil that pools at the bottom of the crankcase or gearbox increases horsepower.
Q:
HOW OFTEN SHOULD I CHANGE MY OIL ?
A:
Yamaha recommends changing the oil and oil filter every five rides.
Honda's Eric Crippa advises changing the engine oil as fequently as posssible and changing the oil filter every fifth time. one fo the problems with a fequent service regimen is that it provokes people to use CHEAPER oil.
Q:
CAN I LEARN ANYTHING FROM MY OLD OIL ?
A:
Yes.
Pay careful attention to the condition of the spent oil. If it looks and smells dirty, you need to service it more often. Extend the time between service intervals if the oil appears and smells clean.
High-end race teams , Formula 1 and Reno Air Racers send their used oil out to have it analyzed. Laboratory tests can use a spectograph to determine what metal particles are in the oil - and whether that particel evidence could be pointing towards a potential failure.
This is too expensive and extreme for a local racer, but you should always sift used oil for broken clutch plates , teeth from gearsor any other unusual conditions.
Q:
WHAT OIL SHOULD I USE IN MY FERRARI ???????
A:
Unless you are a factory racer you can skip this question. If you want the best protection for your 360 Modena berlietta, run an Ester Synthetic, API SG, JASO MB, four-stroke, motorcycle racing oil !
**********************************************************************

  • needsprayer

Posted January 09, 2004 - 05:39 AM

#2

Thanks Dwight,

Makes me feel comfortable with my choice:

Valvoline Motorcycle Oil
Meets or exceeds API SF/SG/SJ
Meets JASO MA specifications

http://www.valvoline....asp?product=76

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • stonewall

Posted January 09, 2004 - 07:38 AM

#3

Hey Dwight,
What are you doing over here stirring up trouble? :D
Just joking with you. Thanks, that's a good article. If I had typed all that a whole new classification of oil would have been invented before I was done. :) :D :D

  • Rokatt88

Posted January 09, 2004 - 09:09 AM

#4

Thanks for the article Dwight. This oil topic is facinating to me. Until I hooked up with Thumper Talk I was very NOT oil savey.

Hey...did you get copyright clearence from MXA? Don't want Jody Weesel to start makin; you ride Yamahas! :)

  • Dual_Dog

Posted January 09, 2004 - 07:13 PM

#5

That's quite an article. Probably the best advice is to read and follow your owners manual. This will tell you which viscosity to use and what grade of oil the motor is designed for.

I have a 98 XRL and it doesn't say anywhere that this oil-frame-design is a "semi-sump" engine, rather it is a dry sump design. It's been that way since 83.

This engine works better now than it did when I bought it since I switched to Mobil 1 15W-50 "red cap" full synthetic for automobiles. This oil has no friction modifiers and the clutch is completely unaffected, in fact, it shifts more smoothly with the full synthetic. The bike even runs cooler. I don't have any verifiable proof, except I like to think so because my legs don't get as hot as they used to.

There's a tremenduous amount of information ou there on this subject. I know first hand because I did a lot of research before switching from Castrol 20W-50 "dino" oil. The full synthetics are expensive and that can be a problem for super frequent oil changers. I've got about 1K really hard miles on my chopper since the last oil change and this air-cooled beast hasn't burned a drop.

Best advice? Use the recommended type, grade & viscosity and change it, and the filter, often. :)





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