Hey Paul,

All glow engines will make the same oily mess comparatively, its the fuel content that contributes to that. A fuel mix comprised of synthetic oil will leave a small amount of residue compared to one with a large amount of castor oil in it.
I use a 15% Nitro- 18% Oil (100% Synthetic) Fuel mix, but add approx. 3 oz of castor oil for a 20% oil content. A small amount of castor is beneficial if you should have a "lean" run. If your OS 52 engine is new (For Break-in) or if you plan to use a Saito I would use a fuel with a little more castor oil in it up to 5%. Saito's do not have an aluminum bronze bushing in the connecting rod. Castor oil is cheap insurance if you don't mind a little mess.

An 8 0z tank should run a 52 at full throttle for about 12 minutes.

Happy Fly'n....