Just finished re boring and honing the barrel to 20 thou over, was told that it may be worth polishing the head to minimise carbon build up and improve gas flow, has anyone get experience of this?

email (option): 79aust@sky.com

Hi Julian...Heavy carbon build up should be removed as it can heat up sufficiently to cause pre ignition. Conversly though, a lighter carbon build up helps to reduce heat loss from the combustion chamber by forming a thermal barrier of sorts, which is a good thing (lost heat being energy lost from the combuston process).
You have to consider here that a 100% efficient engine would be completely cold when running with no heat 'energy' lost.
Polishing the head of a standard motor will look nice, but have no meaningful effect on performance by itself...Ian

email (option): ian@wright52.plus.com