Hi Guys, on some of the gas powered radial engines, a separate lube system is used on the cam gear,it does not rely on the oil in the petrol mix. Is this supplied by an internal pump driven by the crank or cam shafts, andis it supplied by an oil tank in the engine or is it external.I have looked at many pictures of these radials and cannot see any external tanks, only the pulse pump for the carby pump.Any answers? Mark.