This is a new idea to me but on the US Healey boys forum it seems common practice. The idea is to align the plug by using copper washers so that the spark area is centred in the cylinder and not facing the cylinder wall. Numbering the plugs once done, anyone had a go at this?
They also file the tip back to the edge of the electrode..
Did a Google and whilst I could find lots of references, I couldnt find anyone who had done a before and after dyno run.
