Castor Oil for COX Engines: Fact or Myth?

THIS THREAD HAS BEEN MOVED TO COX DISCUSSIONS UPON THE CREATORS REQUEST.
http://coxengineforum.forumakers.com/t648-castor-oil-for-cox-engines-fact-or-myth

Put castor in hot frying pan and burn it. Even burnt it has oil residue. Try thay with sync. oil and see for yourself. It burns to dust. Nothing but dust in pan. Dan

dankar04 wrote:Put castor in hot frying pan and burn it. Even burnt it has oil residue. Try thay with sync. oil and see for yourself. It burns to dust. Nothing but dust in pan. Dan

True, but the article indicated that at 15% nitro, the COX engines did not run hot enough to take advantage of the ability of castor to polymerize in the ball/socket area of the piston, only on the cylinder near the exhaust port. His argument was that a 90/8/2 blend of synthetic/castor/tricresyl phosphate in a 16% total oil mix ran faster than the other combinations and had very little wear over a 10 hour running period.

There are some interesting results from his testing, which he did say were unexpected.

Interesting intial read

I didn't read thru that whole rcg thread,,but did he allow a complete cool down (cold to touch) of the on-again off-again motor,, because that plays a significant role in the life of the motor.

No two engines are the same as well, maybe close, but not exact. It would be very tough to go thru and pick out baseline motors, by metallurgy, tolerances, ect and get two (or three) that match exact or close for a comparable test.

Adding my .051¢ to the fire.

FOOD FOR THOUGHT ???!!! Man !!!! MY brain feels like Garfield after eating 10 pounds of Lasagna! You guys are too smart for me !!!!

I'm just gonna keep using Sig and Glowplugboy and hope for the best !!!!! Now, a couple Tylenol please !!!

Seriously though Andrew, appreciate the courteous nature of your posts on that thread ! I really like to see ideas (however high above my head they may be) and arguments exchanged with respect shown to the premise and it's presenter, whichever side a person made hold.

Everything makoman reported flies in the face of conventional wisdom, but he did attempt to run his tests in as much of a controlled environment as possible. However, PV Pilot's comments about not being able to find 4 identical baseline engines certainly carry weight -- it may have been the luck (or lack thereof) of the draw that the two failed engines would have failed if run with the synthetic oil. Statistical testing requires that the sample size be sufficiently large to remove as much of the bias as possible and his sample is too small to qualify. But, even with a small sample, he does have some convincing data.

Most of us have found, either thru experience or the sharing of information, what works. I guess I'm looking for something that may work better. Kim made a good point about new ideas being exchanged and weighing both sides of the discussion. I have read in other groups comments by posters using lower overall oil content and blends of 50/50 syn/castor packages with no ill results.

When I started in this business, castor was the only lube available. But, synthetics have made significant strides over the past 20 years --- and these are 20 years where COX R&D stood still. I'm as resistant to change as anyone. When CA was first introduced, I thought, "Man, that stuff can't possibly work." Today, I think, "Man, I'm out of CA, what am I going to do?" I think the thread has enough substance that I'm willing to sacrifice a Surestart or two to satisfy my curiosity.

I have several of "old timey" Class C stunt engines that were run on a steady diet of "Power Mist" w/green label for hundreds of hours with castor lubrication. Where PM availabe today, I'd run is in ALL of my engines large and small.

But it's not so I'm shifting to the syntheics oils as I have done in my van which runs Castrol SEMI-synthetic blend as it has for 70K miles since new. I have confidence that it will go 200K miles or more given 7.5K oil/filter changes. I intend to run the van until it expires of "natural causes".

And so it is with my model aircraft engines running synthetic lubricants. (I remember when a 3K engine oil change interval was the standard for automobiles) No longer because the lubricating oil specs have improved so dramatically in recent years.

Switching to synthetics isn't so much wrong as it is different. Remember "leaded" gasoline? "Conventional wisdom often dies a hard death.

Welcome to the future.

i am new to this forum, but i will throw in my .02 anyways.
if it aint broke, don't fix it.
on one hand you have the new fangled synthetic, that may or may not be good/better.
on the other hand, castor oil saw 2 stroke engine since WW1 and is still used today for high powered dirt bikes. the castor bean has been pretty much the same. at some point, i stopped caring so much about the 'best' and settled for 'works fine every time'.
i guess i may have broken down on the road one too many times in search for more speed. nowadays, i value reliablity over possible improvement.

but that is just me.

Someone here ran synthetic fuel on there first cox engine sometime earlier this year and that engine now has no compression.
I will only be running castor in the engines i car about but i may take 2 new SS engines and run them on equal amounts of fuel on synth one castor and see.
But also the quantities must be right.

I thought the correct answer to that story with lubricating oils could give His one of the manufacturers, but unhappy is not near us.

nemoskull wrote:i am new to this forum, but i will throw in my .02 anyways.
if it aint broke, don't fix it.

It's certainly difficult to argue with that philosophy and it has stood the test of time.

OTOH, we have to ask the question, "What if it is broken and we never recognized the problem?" Roy Cox made a lot of money selling piston reset tools. Most everyone (I think) assumes the piston/rod joint loosens because the crimp opens up. But what if the joint loosens because of accelerated wear where the top of the rod comes in contact with the bottom of the piston crown? There's been an extended discussion over in RCG on the forces, and direction of force, placed on the ball joint. Essentially, why does the crimp open up if the piston is always under compression. It's not a 4 stroke where the crank pulls the piston down during intake. We run under compression or power all the time, unless the engine is running a rich 4C.

In any event, I think the thread had enough merit that I want to try a lubricant package with "non-standard" oil ratios. It seems that the tricresyl phosphate had a positive impact on ball joint wear.

Am I advocating that folks change their oil component. Absolutely not. But I do believe that we have moved forward in 50 years and that there may be a better mousetrap -- .

andrew

But the way i see it is that Castor is NOT essential during rich flying but when running lean or prolonged periods of time on the ground especially when lean the engine gets hot and the synthetic oil simply burns off but castor wont begin to boil until it gets to 595f.
So it lubricates even during lean runs.
Indra

nitroairplane wrote:.......but castor wont begin to boil until it gets to 595f.
So it lubricates even during lean runs.
Indra

That's indeed the advantage of castor -- it's ability to polymerize (actually convert to longer chain molecules) and retain its lubricating properties at high heat levels. The thread didn't recommend eliminating castor oil, just that it may not be necessary to run it in as high percentages as previously thought.

True but as the old saying says.
"better safe than sorry"
If i was going for speed i would go 1/2 castor 1/2 synthetic.
But hey i am just a sport flyer and bench runner.

I looked up Klotz while I was reading about Tricresyl phosphate. Klotz makes a lot of racing additives. I presume Nitroil is what Sig and others use. Most of the rest of the products are for gasoline mixes.
I like the Fogon, I can think of all kinds of uses for that.
I'm going back to read about TCP now. It's apparently pretty poisonous, according to what I've read so far.

Rusty --

I believe SIG uses BeNol, Original Techniplate (100% syn) and Super Techniplate (80/20 syn/cas), sometimes blending these to get the mixtures they want.

We now turn the clocks back to about 1985:
My best friend and I were teenagers, who knew some of the local flyers, none of whom were cox or even 1/2A guys, nobody flew less than a .20/.25 except us.
We didn`t get around the other guys that much anyhow,but we flew almost every day the weather was suitable/ish ,read every FM,RCM, and MAN magazines we could get our hands on. Eventually we ran out of COX fuel, but had a ful gallon of 15% coolpower for my K?&B.40 that I only ever flew 4 times.

So, we used the 15%coolpower in our cox`s and averaged 3 worn out cylinder/piston sets each in our cox 049`s, 1 in my peewee 020, and 1 for my 074queen bee. We did this for several years, until one fine day at the hobby shop an actual'COX" flyer was also there shopping and happened to hear us talking.
This "cox" guy set us straight on using the cox fuel, which did cost more than coolpower, but was better for our coxes.

We never had a crankcase that was really shot, a little bit of "free spinning crank action"; but oh my,the piston/cylinder sets we went through over the years were way too many. And when we returned to COX fuels, we could get at least a year out of a piston/cylinder set.

I`m not making any statement about anybody elses findings of tests etc. I just do believe that castor is a good oil to run, and will continue to run castor in my small engines no matter what someone else proves, "it works for me"

P.s., I also run higher nitro fuel than his test 15%

you know, i am tempted to get a couple of brand new cox motors. put on some reall small props and run on on glow fuel with castor, the other with the new stuff. no break in, just hook up to a real big tank and run them side by side till they die.
its wont be perfect, there is still the fuel to nail down, but it would give a rough idea of how much longer a engine will last on either oil.
hey, cant you run on 0% nitro? dont have to be good, just has to run well enough to turn a prop. the lack of nitro should raise temps too. then if you could get whatever synth oil they use, you can rule out the fuel as a variable.

one day, this friday, tho.