Autolite AR3931 Racing Spark Plugs #3931
High Performance Racing Non-Resistor Spark Plug Thread Size 14mm X 1.25 Reach 3/4" Hex Size 5/8" (16mm) Seat Type Gasket Tip Configuration Short Projection Resistor Non Resistor Metal Type Copper Terminal Type No
- Copper-glass seal bonds insulator, terminal post center electrode together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
- Multi-rib insulator reduces danger of "flash-over"
- One-piece terminal post adds strength
- Resistor reduces radio frequency interference (RFI) and electrode erosion
- Cold-formed steel shell precision rolled threads
- Full copper core electrode provides better performance in all conditions