I remember you chasing a source of that camshaft Ash.
It was of course part of the "Dutch" thread in topic too.
That really made me think, and alter my fundamental approach in looking at failure of this type across different engines.
There's currently something of an epidemic in car engines that moved to "reliable" cam chains as opposed to toothed belt that gives a lot of failures to examine.
This honda problem just looks like oil supply, particularly the initial phase of running after just starting. I do think synthetic oils can offer a better outcome as well ....the Dutch thread more or less proving that, in my view. Hadid go the wrong way on viscosity though as he ultimately chased oil pressure as absolute and not the "replenishment" rate at bearing sites.
Low incidence of oil replacement is fundamental ... that now being seen with long gap in modern cars from silly service intervals. They also struggle with guide failure, often plastic in entirety, and fracture being common. But immediate supply of oil to components is of very high value, low viscosity usually helping that rather than "stalling " oil flow durometer pump by the pressure relief valve opening when cold ... effectively causing nil supply to reach extremities through that initial period.
