M8, many thanks for the explanation and the tip about the inverter .... I did actually use a "modern oil" (Agip) 10 years ago, but the oil wsa that good at getting into the pores of the bore that we could never bed the rings and stop oil consumption, so we simply went back to what we had used before ... and yes, I do recognise BP Corse etc ... We put fresh oil (and filter) into the engine after every 4 hours of operation (effectively every second meeting), and run an AFL1HP filter to avoid the risks of a burst filter ... Anyway, thanks for the post ... made lots of sense .... RB
