Head gaskets had been replaced a few months before so det seems likely but mechanic seems to think oil starvation. Engine had 90kmiles approx so can't grumble I guess but have fitted new oil pump to replacement block and have an apexi on order to prevent future issues.
I'll proly keep Mavis off-track from now on, she is awesome fun but too expensive (2nd time engine has been out this year because of track related damage).
Anyhoo, if finances allow and a cheap toy comes up I might be tempted next year
