Non Resistor Plugs

[Paul A.]

[Jimmy G.]

Re: Non Resistor Plugs

43 N are not that hard to find. 44 N run better as they are slightly hotter (in my opinion). In reality almost all serious drag racers prefer Autolites.

[Paul A.]

[Duke W.]

Re: Non Resistor Plugs

Also that non resistor plugs deliver a hotter spark. I’m guessing that’s why most are using a hotter plug?

I'm not sure what you mean by "hotter" spark, but the RFI resistor reduces spark energy, so a non-resistor plug delivers more per spark energy., usually measured in millijoules.

In the context of spark plugs "hotter" means a plug that transfers heat more slowly in order to keep the tip temperature above where fouling can rapidly occur. A 427 in a medium duty truck needs a colder plug than a 427 in a relatively light sports car that rarely sees high load for more than a few seconds at a time in normal road driving.

I don't know why GM installed such cold plugs in Corvettes. AC heat range 5 is more suitable than 3. If one insists on AC plugs resistor type are about all they offer now, and they're manufactured by an outside contractor, not GM. If you're willing to use other brands like Denso or NGK, go to their Web sites and cross the out-of-production AC 45XLS to a Denso or NGK non-resistor equivalent.

Duke

[Paul A.]

Re: Non Resistor Plugs

I'm not sure what you mean by "hotter" spark, but the RFI resistor reduces spark energy, so a non-resistor plug delivers more per spark energy., usually measured in millijoules.

In the context of spark plugs "hotter" means a plug that transfers heat more slowly in order to keep the tip temperature above where fouling can rapidly occur.

Duke

[Jeffrey S.]

Re: Non Resistor Plugs

Paul,
R45 plugs will NOT work in your BB car!!!! You need a 3/4" reach plug ("N" suffix or "XL") The plain R45 is a 3/8" reach and is designed for a small block car.
Jeff

[Duke W.]

Re: Non Resistor Plugs

AC R45 is a 3/8" reach plug okay for small blocks, but big blocks plugs have a longer reach. If you want to stick with AC plugs the R45XLS is the best choice since the non-resistor 45XLS is not longer produced.

Duke

[Paul A.]

Re: Non Resistor Plugs

55F3F0B9-1D01-44E0-A9AA-9C9A5EDE52E1.jpgDuke, Correct again. I did not include the entire plug #, AC R45XLS. Thank you!

[Paul A.]

Re: Non Resistor Plugs

Paul,
R45 plugs will NOT work in your BB car!!!! You need a 3/4" reach plug ("N" suffix or "XL") The plain R45 is a 3/8" reach and is designed for a small block car.
Jeff

Thanks Jeff.