I remember seeing a Dan-Air Ambassador start up at Liverpool airport on the service to Amsterdam they operated in the 1960s, once a day or less for which a dedicated Ambassador was outstationed at Liverpool.
The engines at startup gave off the largest cloud of smoke I have ever seen from an aircraft. It must have been a feature of the Centaurus as someone else from Heathrow once wrote that when an Ambassador started up "it was LVPs for 5 minutes".
Being a radial engine it had the usual problem that when parked a bit of lubricating oil from the crankshaft in the centre of the engine will gradually leak down into the lower cylinders and be burned off on startup, how much dependent on how tight the various components are. But I've never seen one this bad, it must have burned off about a pint of oil per engine. The Centaurus was a sleeve valve engine, which are particularly liable to such problems.