And I have stored engines for 14 years that were run exclusively on full syntetic Cool Power.
Here's what condition I found the rear bearing in when I had to replace a crash damaged front bearing.
I also came across an interesting article about
castor Vs synthetic oil.
Here's a few snips from it.
Why use synthetic oil?
Synthetic oils typically offer high film strength without the wax formation. Wax formation can be undesirable in ringed engines where the wax build up can result in ring sticking which will lead to a ring failure and subsequent engine failure. Synthetic oils also tend to keep the insides of the engines cleaner which results in more consistent combustion.
Some people have argued that Castor oil is better than synthetic oil. Historically this argument stems from the manufacturing process of rc engines. Why is this?
If we consider the demographics of the RC hobby, I think you’ll find it s is mostly 40 to 60 something’s who are most active. When these folk started in the hobby, manufacturing techniques where not dominated by CNC (Computer Numerical Control) machinery but by manned lathes and mills. Engines were mostly cast and liners were not very accurate. These components were not “close fit” as they are today. The use of castor oil would result in a varnish layer on the components that effectively took up some of the tolerance and provided sealing and hence compression.
What is one benefit to using Castor?
It is fairly easily available over the counter and it lubricates well enough.
What is one benefit to using synthetic?
Synthetics oils tend to be more thermally stable at the operating temperatures of RC engines and they don’t leave residue behind in the engine.