Dang, good point.
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I've dug out the info I have on NGK Plugs from a post to the old US Email list
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(Hmm, I need to buy a set of BKR7E's)
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FWIW, I gave a set of 7ES's to a friend with a Rev1 and his engine really didn't like them.
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Part
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#6097
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: BKR7E Stock
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#: 6097
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-
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£1.43
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/
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£1.68
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(not in stock)
Part#4930
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: BKR6E
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- 1.53 ea
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inc
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£12ish all in
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(stock heat range, with resistor)
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Looking back through the archives, others have used:
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(resistorless)
Part
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#5030: BCP7ES Stock
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#: 5030
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-
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£ 1.16
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/
Part
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#: BCP6ES Stock
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#: 4930
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-
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£ 1.01
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The first digit in the NGK part number indicates the heat rating.
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Lower numbers are hotter, higher numbers are colder.
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Without trying to describe the whole NGK part number system, the above part numbers break down as follows, from first letter/digit to last:
B
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- 14mm thread diameter
C
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- 5/8" hex size construction
K
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- 5/8" hex size construction, projected tip
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(ISO)
P
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- Projected insulator type
R
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- Resistor type
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(heat range 2 through 11)
E
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- 19mm
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(3/4"
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)thread reach
P
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- Premium platinum VX
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- High-performance platinum
Y
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- V-grooved center electrode
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(14mm only) 2.5mm insulator
A
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- Special Design
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-
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-11
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- 1.1mm gap
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-
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-8
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- 0.8mm gap For plugs with a flat seat and gasket
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(all of the above, I believe), NGK recommends torquing 14mm plugs to 18.0-25.3 lb-ft in cast iron heads and 18.0-21.6 lb-ft in aluminum heads.
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If you don't have a torque wrench they say to give it between 1/2 and 2/3 of a turn after finger tightness.
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