Which Spark Plugs?

[noddy]

Hi everyone,

Just wondered what the common thought was on which is the best spark plug to use ...

I currently use Champion N5C, but a lot of the MGA guys use and recommend NGK BP6ES.

Which plugs do you use and recommend?

Roger

[canuck]

I do have Champion N5 installed in the Riley only because I am a purist of sorts, (or lazy) and Champion is called up in the manual/parts list. To be honest they have given me no reason to change.  With the crappy E10 fuel we usually have to buy over here the heat range seems to be good.  I also use 'old fashioned' solid core spark wires and the standard Lucas HA12 coil.  

I also have Champion in the MGB, N9Y as called up in the manual. See a pattern developing?  A great many MGB owners swear at and off the Champion and opt for the NGK BP6ES and some even use the resistor plug NGK BPR6ES.

I do not claim to know a lot about spark plugs but I do believe that wires, coil & plugs should be 'compatible'.   Once tuned properly and no untoward issues I chose stay with what works , no?

I believe the N9Y and BP6ES are the same heat range, hence the proliferation of either in the MGB world.  I am not sure if the Champion N5 is the same heat range as the BR6ES. 

BUT, to add to the confusion, I did use the NGK BP6ES in my Jaguar XK120 for many years. The car was called for Champion N5. Car always ran wonderfully, no run on, pinking or difficulty with fuel. I do not remember my thinking as to why the NGK versus the Champion in this car.

This spark plug question may be a bit like what oil brand, or tyres?

Back to you

B

 

[falconriley]

NGK BP6ES are the plugs to use. Perfect for B series BMC, RM's, Nines and 12/4's in standard tune. Modified engines can need another heat range plug I find, like a 7 or 8.
Matthew

[noddy]

Thanks for the replies.

I am being swayed into using the NGK - I am hearing more good things about them and more negative comments about the Champions.

Bruce - like you I am not too familiar with spark plug technical stuff - but have found this very useful ... NGK - classic vehicle guide. 

Interestingly, the guide suggests a B7ES for the 1.5 - a slightly colder plug than the BP6ES - although for the MGA it suggests the hotter plug.

Roger

[2robert4]

I have just found my Champion Book (recommendations for popular cars) dated July 1973 at the back of said book it contains a list of conversions to other manufacturers Plugs. It states B5ES is the direct replacement for N5 and BP6ES is a direct replacement for N-12Y? it went on to explain that the lower the number the colder the plug and its standard plugs are numbered 1 to 25. Whether this applies to other manufacturers is open to debate but the information is food for thought though. Apologies if I have muddied the waters a little.
NP

[canuck]

Chaps,

This discussion is turning out to be as I suspected. Lots of choice & opinion. This is not a bad thing rather I find this interesting.  Too bad we can't be having this in some ones garage with a cuppa! 

So the guide Roger references for NGK sparking plugs indicates a different sparking plug for each the Riley & the MGA , (B7ES & B6es) respectively, yet we are led to believe these two engines are the same.   The same guide calls for a BP6ES to fit the MGB engine.  I am very familiar with the MGB engine, (and its cylinder heads) and here in North America this engine changed much, both in compression figures and cylinder head design, combustion chamber shape, as well as camshaft timing. These changes being mandated by the people that love the planet more than others.  As well over here we see some very poor quality fuel with high levels of Ethanol. Today is much different than when these cars were designed, when Harry Weslake and the factory called up a certain temperature & reach sparking plug.

So, according to me and this NGK guide it is clear there is no 'silver bullet' for a sparking plug choice. Rather there is a good choice for us to experiment with.

If we have a budget we can conduct 'tests' and if not we can use our tried & proven butt meter.  This is my choice.  I have no budget for tests!

I do think a solid points type distributor, (shaft not flopping about), curved to match the engine tune build & fuel type, sparking lead type, copper core and heat range and gap all play a roll in a well running engine. 

Of course well maintained carburetters, tight throttle spindles with no leaks with proper metering needle choice providing proper fuel atomization is paramount.

My BMC cars wear Champion and all I can say, with confidence, is I experience easy start ups, well running, no overheating, never fouling with easy to set carburetters engines.  Thousands of miles per season is the only proof I have, and at spring start up, (sitting with last season fuel for 5+ months) never a bit of grief.  Will I go out and buy NGK types and start swapping? probably not.

Will I tell someone that this or that brand is better than the other, probably not. Each engine & state of tune, (todays world) is a unique example I should think.

Now do we want to start a discussion on indexing? 

Back to you chaps

Bruce

[trymes]

I'm with Bruce, use what works for you. Having said that, all of my cars get NGK plugs. If memory serves, this is what Jeff at Advanced Distributor recommended, but then again, I might be making that up? Either way, they work quite well in the B, the 1.5, and the Daimler. The Riley runs far better than the B, but I'm guessing that's because it received rebuilt carbs when I put it back on the road, and the B probably has worn throttle shafts. Oh, and I'm pretty sure that the Riley has yet to turn 100,000 miles due to MANY years off of the road sitting in garages and a chicken coop (so the story has it).