Goos evening Folks.
I am in the middle of research for alternative of Castor oil.I tell ya the problem.I was assign by our club to brew a fuel for our airplanes.It' a remote control airplane club.Our fuel usually contain 80% methanol and 20 % castor.Sometimes it's 70% methanol,20%casotr,10% nitromethane.The problem with castor is that it cost about 26$/gal and we burn alot of fuel,so i was searching for information on some synthetic lubricant that would have a high flash point and YET mix with methanol throughly.
I found other oil called CoolPower that designed for go carts but it cost just as much as castor .So i started experiment with fluids,I tried automatic transmission fluid-it doesnt mix with methanol,tried penetrating oils,tried WD40 and hyraulic oils,Tried mistery oil and compressor oil. Finally found this forum and though will ask some experts out there.Is there any substitute that i could use or 26$/gal is cheapest as i can go???PLEASE help.......Anyone?

I know there is a German producer of syntetic oils for use in model engines that use a mix of metanol and nitromethane as fuel, but I don't know name and adress.

May be one of the german forum members can help?

How high flashpoint do you need?, i guess you don't want the lube oil to burn, so ash content is no worry?

Not sure about the flash point.I know it's way below castor's.I would say castor's around 600c synthetic oil is about 400c .Thats my guess.

We don't use straight synthetic,there is always a part of castor added just for protection.But when dominant part of the oil is synthetic we always run rich.With excess fuel comes guarantee against oil starvation.
As for ash,i think it's important but not THAT critical.

Flash point on castor oil is aro MSDS und 240C.

Assuming high quality grade castor oil or synthetic R/C oil, and modern engine designs there is no reason to run 10% oil, closer to 5% should protect just as well. In fact many newer engines reccomend a good bit less than 5%. The power gain from running less oil would let you also cut back on your nitromethane concentration by a nearly equal amount. I.E. 10% oil and 10% nitro and 5% oil and 5% nitro should make about equal power.

$26/gallon sounds a bit stiff, locally to me, pre-mixed fuel/oil/10% nitro is around $7 a quart.

There will not be, IMHO, a good cheap alternative to the RC specific oils, all of the cheap dino oils you've been trying are just begging to toast an engine.

I think Kotz in USA have some oils for your purpose. Try this link: http://www.klotzlube.com/
You also have some producers in Germany: http://www.glissol.de/produkt.html (Fuchs)
or you can try this e-mail: RD_modelltecknik@t-online.de