What ARE the best spark plugs for the Datsun 280z?
ClassicZCars forum, Haynes service manual, and many others swear by only one: NGK’s copper core spark plug.
During this smog-crisis I’m having, I did a switch up to help pass smog (more on that later), and after a bit of research, sometimes the plain, simple and cheap solutions work best. This is certainly the case.
But why? Why not platinum? iridium? Hell, if kryptonian-nuclear-nitrous-laced-ium spark plug was real and can wallup Superman, I’d think it would have been the best for that straight L6 engine, right? Nope. Save the precious metals for wedding rings. Platinum et al. may fire hotter, but you’ll notice right away that the contact point is much much smaller. Our 70’s era engines aren’t perfect, so there’s certainly going to be carbon build up over time – so less surface area, easier for carbon to build up and over.
NGK BR5ES (7734) / BR5ES-11 (7634)
B – Thread Size / Hex Size: 14 mm / 13/16″ (20.8 mm)
R – Resistor
Heat Rating Numbers : 5
ES – Firing End Construction: Standard 3/4″ Thread Reach (2.5 mm) Center Electrode
11 – Spark GAP: 1.1 mm (.044″)
The Nissan / Datsun factory service manual says the spark gap should be between .039″ – .043″ (.028″ – .031″ for Canada). So though they’re somewhat pre-gapped at the factory, you should still buy a gap gauge to measure and adjust, checking for variability.
Here’s what the plugs looked like, taking them out of the 280z after 2 years…
Ooo not good. So I replaced each one, and let her rip.
Woohoo! More power, instantly. From the moment I pressed the throttle (and i’m usually kind of a turtle), I notice the difference right away!
Now on to that cat…