Plugs in practice

[JOWETTJAVELIN]

I've read simmitic's highly informative thread on spark plugs:

http://www.mmoc.org.uk/viewtopic.php?f=12&t=28949

I have asked about plugs before, but what I want to know, and a few 'old hands' can doubtless help - what is the difference, if any, in running a standard 1098 on N5 and N9Y in actual practice?

The N5 is a cold plug and has a much shorter reach than the N9Y. There must be some difference in running, surely?

[bmcecosse]

Not really - the N9Y is designed to run with the same 'heat range' as the N5. However the design of the long nose plug is intended to more effectively ignite the mixture, and be less prone to fouling/oiling up.

[JOWETTJAVELIN]

Many thanks.

[bmcecosse]

I remember 50 years ago when the long nose plugs were introduced - and I fitted a set of UN12Y plugs to our family Rover , replacing N 8 plugs, and declared it was 'much better' for the change.......