colder plugs

[Aussi440]

Guys,

I'm running the Champion RJ12YC plugs in my 68 Charger, bone stock 440, it pings a little, I'd like to try some colder plugs.  Has anyone had experience going to Advance Auto Parts and asking for them?  Does anyone have reccomendations for a colder plug I would be able to find?

Ryan

[skip68]

Hey Ryan, NGK XR5 is I think the best plug for these 440's.   I run them and they are the choice plug for most.   chuck. 

[Aussi440]

Thanks Chuck, are these colder than the ones I'm using, or have you just had good experience with them?

Thanks Ryan

[skip68]

I'm not sure, but I have tried tons of plugs and these work the best.  Go to the performance section and ask.   You will get a better resonce.   Firefighhter (Ron) is our engine brains here and he told me to run the XR5 plug.  Good luck. 

[elacruze]

It's unlikely that colder plugs will solve your problem. Pinging that comes and goes with throttle is detonation, not pre-ignition. If you don't have a pre-ignition problem, colder plugs will achieve nothing except fouling a little easier. You need less timing and perhaps a richer mixture in your detonation zone.

[BSB67]

Guys,

I'm running the Champion RJ12YC plugs in my 68 Charger, bone stock 440, it pings a little, I'd like to try some colder plugs.  Has anyone had experience going to Advance Auto Parts and asking for them?  Does anyone have reccomendations for a colder plug I would be able to find?

Ryan

My experience is that the plug can makes a big difference especially if the one you are using is too hot.  A J12Y is a little to hot for a stock compression ratio 440.  A NGK R5670-6 or an Accel 134 would be equivalent to a J11Y.  An NGK R5670-7 would be like a J10Y, and a R5670-8 and Accel 132 would be like a J61Y.

I would recommend the R5670-7.   They will foul a little sooner but if your a gear head, you'll probably changethem before you need to anyways.  Make sure that your cooling system is perfect and run a 160 degree thermostat.  If these don't work, slow the timing curve down before you pull total timing out.