HOME and how to join Forum Open Area General Scott topics Spark plug caps Re: Re: Spark plug caps

#13164
BRIAN MARSHALL
Participant

The machining of spark plug bodies to increase the reach of the plug was nothing to do with plug/radiator clearance problems, and was to reduce the shrouding of the electrodes caused by using short-reach 18mm plugs in the Scott cylinder head. There has been a dearth of suitable longer-reach 18mm plugs for many years, until the recent manufacture of the KLG ML50 by Tim Green. Not only is combustion improved, there is a useful increase in compression too! There was a good article by Glyn Chambers in Yowl about machining NGK plug bodies to achieve these ends, but it was a good few years ago.
Brian