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spark plugs

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I know this has been brought up in the past but I cannot find the simple answer. What are the proper plugs for a BJ8 64. Are the Champion N12YC Moss sells OK?
 
The Robert Bentley manual shows UN12Y sparking plugs for everything from BN4 to BJ8. My original manual shows N5 sparking plugs for BN4 to BJ7. That is as far as my manual goes. It is possible that N5's were canceled in favor of UN12Y. There should be cross references on a Champion chart that show the proper plug for todays market. You also might find a nice platinum plug to use.

SB
 
Hello TH,
I would go with the manual, the N5 is an old grade
and if my memory is correct is a recessed nose plug (as they all were then). Incidentally N is the length of the thread, 3\4" I think. Champion have improved their plugs and the reference number has altered with that.

Alec
thirsty.gif
 
I have found the NGK BP6ES plug to run a lot cleaner than the Champion brand.

Seems like the Champions don't have the energy to clean themselves off if they get fouled (if caught in traffic, long periods of idling, etc.).

I have tried both BP5ES & BP7ES and found the 6's to be the best one no matter which carbs are on the engine (stock 2x1-3/4 SU, stock 3x1-1/2 SU and the current Weber setup).
 
I mostly agree with Randy who seems to have been posting at the same time that I was.

Everyone seems to have their own preference. I like the NGK plugs due to their wider heat range for a given plug. The B6ES is equivalent to the original. The one range colder B7ES would be good if you are running it hard all of the time. B = 14mm thread, 6 = heat range, E = 3/4" thread reach, S = standard 2.5mm center electrode.

The projected nose plug such as the BP6ES is preferred by some tuners, but I haven't really seen a large advantage to it. The P in the second letter where applicable = projected nose. Note that with NGK, the higher heat range number = a colder plug.

A really good plug for a hard to light off racing engine is the B7EV which has a fine wire gold palladium center electrode. It is hard to find & costs much more than the standard plug.

As you can see, I really prefer the NGK to most other brands, but really, almost any plug will work. Kind of like whether you prefer strawberry or chocolate milkshakes.
D
 
Modern cars with electronic ignitions seem to use a much larger spark plug gap than older cars with the old point capacator ignition. Anyone have any thoughts or experience using plugs with a wider gap when runing an electronic ignition on a Healey?
 
Have you noticed that most of the wide gap - high voltage layouts have much larger distributor caps & rotors? Or lately, one coil for every one or two cylinders. The smaller caps will not reliably withstand the higher required voltages without cross firing or the spark going to ground.
D

[ 05-09-2004: Message edited by: Dave Russell ]</p>
 
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