Bottom Line:
Get
for your Zcar!
Anne G. Kaye recommends them!
Comparisons:
Old vs. NewAbove, on the left, is the tried and true NGK BR6ES-11 copper plug that has been around for years. On the right is the projected plug. Look at the plug history below and try to figure out why Nissan started with projected tips then switched to non-projected for N42 and most N47 heads then switched back to projects midway through the N47 line. My guess is pollution or compression related?
The part number of projected plugs started with BPR... where the P signifies a projected plug. The 6 and 5 numbers are the arbitrary NGK temperature at which the projection stays when operating. Lower numbers are hotter so the projection on a 5 plug is hotter than on a 6 plug. This heat helps to burn off carbon, fuel additive and oil deposits from the plug and this cleanliness makes it operate better. Plug temperature does not affect how hot the combustion chamber is (air/fuel mix does). The only caution when running a hot plug is that it can trigger detonation in a turbo application or high compression application. However, many people recommend NGK 5 heat range plugs and report no problems when using them.btw the R in the product code means a resistor is integrated to reduce RF noise interference. My plugs measure ~ 4.5kohms of resistance.
Old vs. Newest (latest and greatest)
On the right is the newer "V-Groove" NGK ZFR6F-11 copper plug whose tip projects further into the cylinder than a BPR and promotes a better burn: "[The ZFR6F-11] is a 'V-Power' plug with a projected tip which extends out into the center of the chamber. Projected tips provide a more complete burn through the rev range, creating "free horsepower" and improving throttle response. They also simulate advancing the timing slightly by firing the mixture faster."
normal center conductor vs. v-groove center conductor
NGK Product Code Chart:
NGK Iridium IX Plugs
If the old and new are not good enough then get the latest NGK "Top of Line" Iridium plugs that substitute for the above. The part numbers are BPR6EIX-11 and ZFR6FIX-11.
The iridium plug has a finer center conductor that is made out of the tougher metal. They last longer and spark is different due to the finer "pin". Here is the blurb:
Iridium is a silver-white precious metal that is among the densest materials on earth. Since it’s so dense, it will outlast Platinum and Copper plugs. Plus this ultra- hard material also enables the plug center electrode to be 25% narrower than Platinum, and 75% narrower than conventional nickel electrodes, which requires less voltage to spark, and delivers increased burn efficiency, sparks at leaner air/fuel mixtures, and produces better gas mileage and higher horsepower. Iridium plugs are a must for turbocharged and high compression or high revving NA motors.
WARNING: Do not gap Iridium plugs, stress to the tip may cause it to break off during use!!
Historical Z Plugs
-1970-1974 240 and 260Z's came with BP6ES
-1975-76 280Z's came with B6ES
-1977-'79 280Z and 280ZX's came with B6ES-11
-1980 280ZX's came with BP6ES-11
-1981-82 280ZX's came with BPR6ES-11
Z Plug Gap
1.0 to 1.1mm
0.039 to 0.043in
Z Plug Torque
10 to 12ft-lbs
WARNING: Always try to remove plugs with engine cold.
NGK Plug Wires
Early Zcar's use NGK part NE-61 (not shown but similar)
-NGK are a stainless steel variable pitch. The variation in winding
(loose-tight) is good for noise suppression thus preventing noise on
the car radio or interference with the in car computer.
