Why Castor?

[2strokeforever]

look at the skirts, 20$ says amsoil would seize before that hole got there, but for sure there would be a shitload of scoring

amsoil dominator fire point 198f

amsoil saber fire point 237f


maxima 927 fire point 480f

amsoil better? at less than half the temp it lights up and dissapears

im guessing blenzall is even higer because its 100% castor and 927 is only 40% i think

[fastkart]

That looks like detonation burning a hole in your piston, your pre-mix oil isnt going to effect the damage from this...

It was definately lean, which leads to why I post the pic... lack of new oil, high temps and still lubricating. When I tore it down, the piston and sleeve were still coated in oil.

[AlisoBob]

When I tore it down, the piston and sleeve were still coated in oil.

[M.F.D.B.]

It was definately lean, which leads to why I post the pic...

Or, too low octane, or too much advance...

[100hp honda]

typically i think your true castors are 550+ fire point. not sure how that fits into the big picture because im no chemist

[fastkart]

It was definately lean, which leads to why I post the pic...

Or, too low octane, or too much advance...

Lean, fo' sho. It was the end of the race season, motor had 2 nites from fresh, used fresh C12 (used C12 all year), timing wasn't changed, but the temp was about 25* cooler than the previous race and the humidity was down too, but I failed to rejet.

[2strokeforever]

typically i think your true castors are 550+ fire point

either way when it gets hot synthetics cant compete with castor

[durkn]

I've been using 927.
I've been mixing it at 40:1, but it seems like I should use less oil.

What are you guys mixing at?

[AlisoBob]

40:1

The rod big end bearing is the hardest thing to lube.

Some guys run oil ratios out to 50:1, and say.. " The piston looks fine!!"

Its not the piston they should be worrying about.

[Tharrell]

I've been using Klotz.
I used the Techniplate but switched to Benol which is total castor.
I mix at 32:1

I just rebuilt my 2001 CR250 and it's had nothing but Benol.
I'm gonna pull the topend at the end of this season and inspect.

http://www.klotzlube.com/techsheet.asp? ... bmit2=View

Smoke Rating: 5 1 = fog - 10 = no smoke
Clean Burn™: 5 1 = heavy deposits - 10 = no carbon
Film Strength: 10 1 = failure - 10 = no wear
Pour Point: -9°F
Flash Point: 555°F
Maximum RPM: 10,000
Viscosity @ 100°c: 15.7 cSt Typical
Product Color: Red

[AlisoBob]

I'm not a Klotz fan.

Jay has race motors, play motors, trail bikes, hillclimb bikes, dune bikes..... every kind of CR500 you can imagine.

All run Klotz and he's had more than his share of piston issues.

'927 or Blendzall for me.

[Tharrell]

I used to run Blendzall back in the 70's.
Wonder why he's had problems with Klotz?

I was just on the Blenzall, Klotz and 927 pages snooping around.
I considered Blendzall and 927.
I guess I'll need to get off Benol for the winter.
What to use then?

[100hp honda]

I'm not a Klotz fan.

Jay has race motors, play motors, trail bikes, hillclimb bikes, dune bikes..... every kind of CR500 you can imagine.

All run Klotz and he's had more than his share of piston issues.

'927 or Blendzall for me.

im sure theres more to the story than brand of oil . one guy said this on another site: qaulity can not make up for qauntity....ever

jerry hall said this just few weeks ago: On a premix type of lubrication system my experience has shown that one should mix the fuel / oil ratio for the worst-case situation. An engine that is ONLY going to idle will get all of the lubrication it needs at 80 to 100 to 1. A two-stroke that is at high rpm and has had its throttle wide open for more than about 5 seconds needs a 15 to 20 to 1 ratio. The oil injection systems on the snowmobiles and boat engines mix the oil with the fuel at the above ratios to suit the rpm and throttle position . After working on thousands of two strokes for over 35 years the oil ratio has proven to have a much larger role in engine reliability than the brand of oil in the general purpose two-strokes. In the most extreme cases like the 50 hp 125cc engines, the castor oil gives use the longest engine life. My testing has also shown that my two-stroke engines will make more power at 15:1 ratio than a 50:1 ratio if you have any tuning abilities.

It makes me happy when I see my customers engines smoke. It tells me that they are not going to have lubrication related failures. If you are having problems fouling spark plugs, you are using too much oil for the way you are riding your bike or you need to work on you carb tuning skills. One must mix the fuel, tune the carb and then ride it for the application for which it was tuned or suffer the consequences.

An engine use for recreational purposes usually needs more oil in the gas than a drag engine. It is not uncommon for recreational riders to spend 10 to 15 seconds or more running wide open down a dirt road or doing laps in a bowl at the sand dunes. The oil layer that is on all surfaces in the crankcase may not even reach the stabilization point when the throttle is closed on a drag engines extremely short periods of full throttle. The criterion that determines how much oil should be used in the fuel is the time spent at wide-open throttle! An 80 cc moto-cross engine will spend much more time a wide open throttle than a 250 on the same moto-cross track. … so the 80cc needs more oil in the fuel than a 250 for moto-cross application. Put a paddle tire on a 250 or run a 250 in a desert race and now the 250 requires as much oil in the fuel as the 80cc engine.

[bwalker]

In a CR-500 the rpms are pretty low. I have no reservations in regards to using Yamalube 2R at 32:1 for trail and MX use and at 20:1 for the dunes. It burns very clean at these ratios with the caveat your jetting is on, protects well during long term storage (like our 6month long winters..) and mixes/stays mixed well.
Castor's forte' IMO is shifter karts, 125's and the like that run screaming RPM's at high loads, yet are tore down frequently.
With that said if I was going to use an oil with castor in its formulation it would be Maxima 927. Its cleaner than most castor oil blends and I suspect it doesn't have alot of castor in it.

[mr500]

I used to be a big fan of 927 at 40:1 but after having sticking rings / power valve on my KTM 300 and decomp valve on my 500 I had to say good bye and moved to Amsoil Saber 80:1.
I been running everything at this ratio and its super clean, all trail ridden so maybe not the best conditions for 927 anyway.
When I would go to start a bike after sitting for a while using 927, I would have to drain the carby or they wouldn't start and a stream of brown crap would come out.
With Amsoil Saber it seems to have a fuel stabilizer as there is no need to drain the carby ( If I do fuel is clear blue) before starting.
I have run 100 hours at 80:1 on my 300 and replaced the piston it came out nearly prefect. The ring gap was still in spec using Saber while the previous piston using 927 after 100 hours the rings were way under spec.
I later drowned the bike and later noticed a slight bearing noise, when stripped down one crank bearing had rust marks, the rod bearings were perfect and in spec and had no signs of overheating.
Replaced both crank bearings and all was good again.
In Aus Saber is half the cost of 927 and I'm using half as much per tank as well!
I feel as long as you follow the oil manufacturers recommended ratio you can't go too far wrong.
Just my experience.

[exit90a]

I used to be a big fan of 927 at 40:1 but after having sticking rings / power valve on my KTM 300 and decomp valve on my 500 I had to say good bye and moved to Amsoil Saber 80:1.
I been running everything at this ratio and its super clean, all trail ridden so maybe not the best conditions for 927 anyway.
When I would go to start a bike after sitting for a while using 927, I would have to drain the carby or they wouldn't start and a stream of brown crap would come out.
With Amsoil Saber it seems to have a fuel stabilizer as there is no need to drain the carby ( If I do fuel is clear blue) before starting.
I have run 100 hours at 80:1 on my 300 and replaced the piston it came out nearly prefect. The ring gap was still in spec using Saber while the previous piston using 927 after 100 hours the rings were way under spec.
I later drowned the bike and later noticed a slight bearing noise, when stripped down one crank bearing had rust marks, the rod bearings were perfect and in spec and had no signs of overheating.
Replaced both crank bearings and all was good again.
In Aus Saber is half the cost of 927 and I'm using half as much per tank as well!
I feel as long as you follow the oil manufacturers recommended ratio you can't go too far wrong.
Just my experience.

Very interesting. Why did you choose Saber over Dominator or Interceptor? Currently restoring a 1997 CR500R and plan to use one of these three Amsoil products. Still trying to determine which would be best and at what ratio. Mostly trail riding with the occasional hoon.

[Rustynuts]

Fantastic write-up on Castor!

quote=AlisoBob post_id=932 time=1181934243 user_id=2]
CASTOR OIL
By Bert Striegler.


Back in 1983 there was quite a controversy in magazines about the tests that were necessary to measure the "lubricity" of various oils that might be useful in engines. Castor oil was used as the benchmark, but it was obvious no one knew why this was so. They apparently got a lot of info on various industry tests of lubricants, but these were really designed for other purposes. This was my answer. I will remind you that I was a lubrication engineer and not a chemist, but I drew my chemical info from Bob Durr, the most experienced lubricant scientist in the labs at Conoco.

Bob worked with my group on many product development projects and I can tell you that he is one smart hombre! Small changes were made in the text, but surprisingly very little has really changed since this was originally written. Here goes with the answer:

"I thought I would answer your plea for more information on castor oil and its "film strength", which can be a very misleading term. I have never really seen a satisfactory way to measure the film strength of an oil like castor oil. We routinely use tests like the Falex test, the Timken test or the Shell 4-ball test, but these are primarily designed to measure the effect of chemical extreme pressure agents such as are used in gear oils. These "EP" agents have no function in an IC engine, particularly the two-stroke model engine types.

You really have to go back to the basics of lubrication to get a better handle on what happens in a engine. For any fluid to act as a lubricant, it must first be "polar" enough to wet the moving surfaces. Next, it must have a high resistance to surface boiling and vaporization at the temperatures encountered. Ideally the fluid should have "oiliness", which is difficult to measure but generally requires a rather large molecular structure. Even water can be a good lubricant under the right conditions.

Castor oil meets these rather simple requirements in an engine, with only one really severe drawback in that it is thermally unstable. This unusual instability is the thing that lets castor oil lubricate at temperatures well beyond those at which most synthetics will work.

Castor oil is roughly 87% triglyceride of ricinoleic acid, [ (CH3(CH2)5CH(OH)CH2CH=CH(CH2)7COO)3(OC)3H5 ], which is unique because there is a double bond in the 9th position and a hydroxyl in the 11th position. As the temperature goes up, it loses one molecule of water and becomes a "drying" oil. Another look at the molecule. Castor oil has excellent storage stability at room temperatures, but it polymerizes rapidly as the temperature goes up. As it polymerizes, it forms ever-heavier "oils" that are rich in esters. These esters do not even begin to decompose until the temperature hits about 650 degrees F (343 deg C). Castor oil forms huge molecular structures at these elevated temperatures - in other words, as the temperature goes up, the castor oil exposed to these temperatures responds by becoming an even better lubricant!

Unfortunately, the end byproduct of this process is what we refer to as "varnish." So, you can't have everything, but you can come close by running a mixture of castor oil with polyalkylene glycol like Union Carbide's UCON, or their MA 731. This mixture has some synergistic properties, or better properties than either product had alone. As an interesting sidelight, castor oil can be stabilized to a degree by the addition of Vitamin E (Tocopherol) in small quantities, but if you make it too stable it would no longer offer the unusual high temperature protection that it did before.

Castor oil is not normally soluble in ordinary petroleum oils, but if you polymerize it for several hours at 300 degrees F (149 deg C), the polymerized oil becomes soluble. Hydrogenation achieves somewhat the same effect.

Castor oil has other unique properties. It is highly polar and has a great affinity for metal surfaces.

It has a flash point of only 445 degrees F (229 deg C), but its fire point is about 840 degrees F (449 deg C)! This is very unusual behavior if you consider that polyalkylene glycols flash at about 350-400 degrees F (176-204 deg C)and have a fire point of only about 550 degrees F (288 deg C), or slightly higher.

Nearly all of the common synthetics that we use burn in the combustion chamber if you get off too lean.

Castor oil does not, because it is busily forming more and more complex polymers as the temperature goes up. Most synthetics boil on the cylinder walls at temperatures slightly above their flash point. The same activity can take place in the wrist pin area, depending on engine design.

Synthetics also have another interesting feature - they would like to return to the materials from which they were made, usually things like ethylene oxide, complex alcohols, or other less suitable lubricants. This happens very rapidly when a critical temperature is reached. We call this phenomena "unzippering" for obvious reasons.

So, you have a choice. Run the engine too lean and it gets too hot. The synthetic burns or simply vaporizes, but castor oil decomposes into a soft varnish and a series of ester groups that still have powerful lubricity.

Good reason for a mix of the two lubricants! ( " 927 " is a mix as described here!)

In spite of all this, the synthetics are still excellent lubricants if you know their limitations and work within those limits. Used properly, engine life will be good with either product. Cooked on a lean run, castor oil will win every time. A mix of the two can give the best of both worlds.

Like most things in this old life, lubricants are always a compromise of good and bad properties. Synthetics yield a clean engine, while castor oil yields a dirty engine, but at least now you know why! "

Bert Striegler

Bert was the Sr. Research Eng'r. (ret.) at Conoco Oil Co.
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