Rover Sports Register Forum

Hello everybody, Can sombody tell me what type of Spark Plugs to use in my recently acquired 1938 Rover 12 Saloon? I have a Rover 10/12 Instruction Manual that recommends Lodge CB14 plugs but I have so far been unsuccessful in finding an equivalent, In any case the Instruction Manual is dated 1945, will that still apply to a 1938 model? There does not appear to be any reference to type of Spark plugs in the RSR workshop manual either. I hope someone can help Cheers Trevor

Hi Trevor. From what I've been told it isn't a good idea to fit Lodge plugs to the car.
Modern fuels burn much hotter than their 1938 equivalent and the plugs do not work well.

I have replaced my Lodge CB14 with NGK B5ES and they seem to work well

As 47p2 says the old plugs (if you can find them) will not like the modern fuels produced today. NGK or Champion equivalents are designed to work at the higher tempertures for example NGK B5ES or NGK B6ES which I have used in two Rover 12s and an Austin 16 and have given trouble free service. Just for info in NGK plugs, the B is thread size 14 mm 5 is a heat rating E is the reach or depth and S the position and type of electrode. I know I don't like the idea of having japanese plugs in my car I would much rather use as close to original as possible, and there are Champion equivalents, but you never see them if you have the plug cover on and they do work well.

Hello , I don'tk now if you are sorted with Lodge CB14 Spark Plugs , but if you are having difficulty still obtaining originals contact me on chills781@btinternet.com as I have 4 unused and still in original LODGE PLUGS LTD , RUGBY boxes ,

Regards

Colin

I saw your post ref plugs and purchased some NGK B6ES for my 1936 12 saloon but they seem to be a very long reach plug. (ie about another 5 to 6 thread lengths)
than the ones I took out Champion L86C, which had been running well.
Can you please confirm that the ones suggested NGK B6ES is correct as I dont want to damage the head threads or piston top.

The L86C has a reach of 12.7mm where as the B6ES has a reach of 19mm.

I'm unsure what the original plugs for your engine are but an equivalent replacement for the Champion L86C would be the NGK B6HS

Maybe one of our members with a 1936 12hp can advise better

Hence my question from previous details listed above.
Dave

Hi Dave
All though Rover specified and fitted 1/2" reach plugs the cylinder heads are machined for 3/4" reach plugs. So you can fit the longer reach plugs as long as they are not extended nose plugs such as Champion N9Y. I am using Champion N5 in my 16.

Thanks Tony