Spark Plug Choices 1946 10

[nigels]

Hi,
I recently picked up some new spark plugs for my '46 10 saloon. Bought them as a service kit from ebay for the model. When I removed my first plug I found my car has NGK BP5ES plugs. I was supplied Champion J8C. No big deal I thought but when I compared the plugs the NGK I have in the car now has a much longer threaded section and hence the electrode is much further into the cylinder head. Anyon got any thoughts on what is correct for the car? or does anyone use Champion J8C?
Thanks Much
Nigel

[jefflee]

Hi Nigels, your coments make me smile, the P2 spark plug question comes up at least once a year with lots of opinions,
The original plugs were a little shorter, but i can say i have used NGK BP5ES for donkeys years in 12 14 16 & 20hp p2s
I once had a bad plug, but because they are available from any local motor spares you can take it back & swop it.
Any ignition problems ive had has never been these spark plugs,
You can also get a slightly hotter or colder plug no BP4ES or 6, the hotter plug helps if its oiling up.
Cheers Jeff.

[Rover Ron]

My '46 Ten doesn't 'like' NGK plugs, I always fit Champions

[nigels]

Thanks Guys, apprecaite the posts. Apologies I should have carried out a topic search before posting! Have decided to fit the champion J8 plugs as suplied. Thanks

[luli]

During a recent visit to Beaulieu Autojumble I had happened to find Lodge CB14 spark pluges – the genuine Rover P2 spark plugs. This gave me the opportunity to compare their size with modern long and short stem plugs like Champion J8.

The Lodge CB14 is in the middle. Obviously, The short plug is too short, and the long one is too long. Since with the longer spark plug the spark is closer to the combustion chamber it will give a better ignition. Is there a danger that the longer plug will hit the piston? The following pictures show that it is far enough above the bottom surface of the engine head. It is unable to hit the piston.