Morris Minor Owners Club

On my '57 Traveller (948cc engine 9M U H 506825), I'm lucky to find cylinder compression of 150 150 145 150 front to back. Note that the car spent its life since 1957 in New Zealand, until a three years ago.

The plugs in the engine when I received the car six months ago are Champion N4C. The engine starts quickly (full choke when cold), warms, revs smoothly, and idles peacefully. Plug tips are clean (slight grey coating).

In this Tips thread ( viewtopic.php?f=12&t=28949 ) I don't see N4C even mentioned. On several online auto parts sites, I see "N4C does not fit your 1957 Morris Minor".

Would you recommend keeping the Champion N4C? or would you recommend something else. Typical driving here in Connecticut is 45 mph, rolling hills, temperatures between 50 and 90F.

Thanks!
Tom M.

The N4C plug is a cold running plug born out by the grey colour of the electrode. The electrode should be a nice biscuit colour.
The N4C plugs should be replaced with a hotter running plug of at least N5. My preference would be N9Y. The N9Y plug has an extended nose so any fouling is burnt off leaving a more efficient plug.

Thanks Phil. I'll try the N9Y (which seems now to be N9YC) for road driving around 50 miles, and compare with the current N4Cs.

Several online plug sites report that the N9Y does not fit the 1957 Morris 948. Hope that's an error in the website, not in the plug choice.
Tom M.

The N9YC (C is for copper tip) will fit and can be used in the 948cc 'A' Series engine with out any problems.
I have fitted and used the N9Y and N9YC over more years in the 948cc 'A' Series than I care to count.