Castor Oil-interesting facts

[KD57]

Be aware that all brands of castor bean oil are to a greater/lesser degree Hydroscopic, can in certain circumstances absorb up to six times it`s own weight of water ie, the note of rusting. Way back when I raced 125&250 2 stroke GP motor cycles my engine tuner always very strongly insisted that all fuel be drained from tank/carb,rinsed through with neat gas &any fuel left over dumped.He stated that IHO 7/10 days was the shelf life, after that the effect was noticeable, +any mix left in an alloy/mag tank will after a period corrode at the high tide mark,Something I found to my cost on buying a used 4 stroke race bike that had been standing for some 8 months & the castrol R oil had drained down to the crankcase & at high tide mark had almost rotted through Be observant Guys or it may get expensive

We also used it in our race bikes back in the 70's but other than smelling good, it was a PITA to use, gummy, and not clean at all. It also doesn't stay mixed very well. But at the time, it was the only oil that would allow a modded high revving race motor to survive. It also turned to jello if you accidently mixed petro based oils w/ it.

 

[ray benson]

Is castor bean the best?
http://www.redlineoil.com/content/files/tech/Two-Stroke Technical Info.pdf

 

[Article10]

Great video, I had the great experience of a life time working as mechanics apprentice and then as a newly licensed A&P mechanic at the Old Rhinebeck Aerodrome in the late 80's and early 90's. The first set of log books I signed were on an Avro 504K with an 110 hp LeRhone.

The 160hp Gnome and the 230hp Bentley rotary engines are still my favorites.

At ORA we would get the castor oil in 55 gal drums from the Maybaline Cosmetic company.

 

[Haywire Haywood]

I've still got my stash of Mobil1 Racing 2T. They're marked with an expiration of Nov06. LOL

Ian

 

[tdi-rick]

Is castor bean the best?
http://www.redlineoil.com/content/files/tech/Two-Stroke Technical Info.pdf

Well, it depends......

If you are keeping revs below 18,000RPM or so, the very best synthetic ester based lubes are very very good, (eg. Motul 800 2T, Elf XTX 976 probably Redline, etc) but for the engines spinning up tp 23,000RPM, eg. International 100cc kart engines, all the best kart engine oils (best IMO = Elf HTX 909, Silkolene Pro KR2, Maxima 927, etc) still contain castor oil.
Motul claim their kart engine oil, rated to 23,000RPM is totally synthetic ester based. Whether there is any castor in it ?? (castor oil esterfies in use)
Also note that the recommended mix rate of the kart oils is around 6% (18:1) whereas the bike oils are usually mixed anywhere from 4%-3% (25:1 to 33:1) for GP road racing and as lean as 2%-2.5% (50:1 to 40:1) for MX/enduro.

Re moisture, quite a number of the good race oils contain compounds like calcium sulfonate to prevent the throttle slides sticking in the wet.
I know that Motul definitely use it in both versions of 800 2T, and I'm guessing the other blenders do too as they often advertise that their formulations contain compounds to prevent throttle sticking in the wet.
If used, Calcium sulfonate is a damned good rust inhibitor, it's the soap/thickener used in the best marine greases but I'd still be a little worried about moisture absorption long term. I know with the straight castors, (R30) we dumped the mix immediately after use but that was more to do with the mix going off, although I've heard of Castrol's old A747 having some 'issues' in the wet (throttle sticking) that the newer XR77 overcame.