Page 781 - 2022-23 Auto Performance Drag Racing

2022-23
Spark Plug Heat Range/Cross Reference
DRAG RACING
Thread Heat Standard Non-Resistor Spark Plugs Size/Reach Hex Range Autolite Champion E3 NGK
Chevrolet, Chrysler (Wedge), Oldsmobile, Pontiac - Standard Reach - Flat Seat With Gasket
Hot — — — —
Power/Projected Tip Non-Resistor Spark Plugs
—— 14mm/3/8" 13/16" AUT353 CHPJ4C
—— Cold — —
Chevrolet (Big Block), Chrysler (Hemi) - Flat Seat With Gasket
Accel Autolite
— —
— AUTAR73 — AUTAR72 — —
— —
— —
— AUTAR3911 — AUTAR3910† — —
— —
— —
— —
— AUTAR53 — AUTAR52 — AUTAR51 — AUTAR50 — —
Champion
— — — — —
CHPC63YC CHPC61YC CHPC59YC CHPC57YC —
— — — — — — —
E3 NGK
— NGKR5670-5 — NGKR5670-6 — NGKR5670-7 — NGKR5670-8 — NGKR5670-9
— —
— NGKR5672A-8 E3PE3.106‡ NGKR5672A-9 — NGKR5672A-10
— —
— NGKBPR5ES — NGKBPR6ES — NGKBPR7ES — —
— — — — — —
Hot 14mm/3/4" 5/8"
Cold
— NGKBR6S — NGKB7S — NGKB8S — —
AUTAR3935 —
AUTAR3934 — E3PE3.103‡ NGKR5671A-8
AUTAR3933† CHPC59CX E3PE3.102‡ NGKR5671A-9 AUTAR3932† CHPC57CX E3PE3.101‡ NGKR5671A-10
— NGKR5671A-7
Chevrolet (Big Block), Chrysler (Hemi) - Flat Seat With Gasket
AUTAR3931 —
— NGKR5671A-11
— — — — — — — — — — — — — —
14mm/3/4" 13/16"
Hot — — AUTAR2593 — AUTAR2592 — — — — — — — Cold — —
Chevrolet (Small Block), Ford (Small Block) - Conical/Tapered Seat
Hot — — ——
— — ACL0276S-4* — — NGKR5673-6 — —
—
—
—
—
—
—
— ——
14mm/.460" 5/8"
AUTAR135 AUTAR134 AUTAR133 AUTAR132
CHPV63C — CHPV59C CHPV57C
— NGKR5673-7 — E3PE3.105‡ — — E3PE3.104‡ NGKR5673-8 —
— NGKR5673-9 — — NGKR5673-10 —
AUTAR13 AUTAR12 —
—
—
— AUTAR94 AUTAR93 AUTAR92 —
— —
— NGKR5674-6 — NGKR5674-7
Cold — — Chevrolet (Big Block), Ford - Conical/Tapered Seat
Hot — —
— — —
14mm/.708" 5/8" AUTAR474 CHPS59C — AUTAR473 — E3PE3.108‡
Cold AUTAR472 CHPS55C — Ford (Windsor and Big Block) - Conical/Tapered Seat
Hot — — — 18mm/.460" 13/16" — — — Cold — — —
E3PE3.107‡ NGKR5674-8 — NGKR5674-9 — NGKR5674-10
—
— — — — — — — — — —
— — — — — —
CHPRS9YC ——
— — NGKR5724-8 CHPS59YC E3PE3.109‡ NGKR5724-9
— — NGKR5724-10 ———
— — —
— — NGKAP8FS — — — —
AUTAR33 AUTAR32
Important Note: Use cross reference chart as a guide only. Due to differences in design and material, plugs listed in cross reference are not exactly alike.
* “Shorty“ spark plug for added header clearance, sold in 4-pack. ‡ E3 DiamondFIRE fixed gap spark plugs cannot be adjusted.
† Special Autolite Racing "X" style electrode spark plug that alleviates piston/spark plug clearance issues is also available; simply add “X” to end of part number.
TECH TIP
• Determine the thread diameter, length (reach) and whether tapered or gasket (flat) seat. • Select gap style.
• Select heat range.
• Adjust fuel mixture and spark advance timing for maximum performance.
Spark Plug Diagnosis
Normal
Pictures Courtesy Of Autolite
• Inspect plugs and pistons for evidence of detonation, abnormal combustion or excessive temperatures.
• Stay with the same plug type after final heat range selection unless major modifications have been made (increasing the horsepower or operating range).
Spark Plug Heat Range Tech
A spark plug’s Heat Range, defined as the measure of how fast the tip of the plug dissipates combustion heat, can range from as low as 500°F to as high as 2,500°F. Manufacturers offer plugs in many heat ranges, from cold through medium hot, to very hot. It is impera- tive that the plug stay cool enough to prevent pre-ignition or electrode destruction, and still remain hot enough to burn off combustion deposits that form at the firing tip. A plug that is excessively cold or hot for the application in question will eventually cause the engine to misfire. When working with an engine that is stock or mildly modified, it is often best to use the plug recommended by the car manufac- turer. However, if the compression ratio has been altered, a different heat range plug may be required. Many racers rely upon their engine builder for plug heat range recommendations. If a racer is unsure of the correct heat range to use, it is always recommended to “stay on the safe side” and use a colder plug. A switch in heat range can change the temperature of the spark plug tip by 70-120°F. If the plug se- lected is too cold, it will eventually foul and misfire, but it will not damage the engine. A plug which is too hot can cause pre-ignition and detonation, often resulting in a severely damaged engine.
Fuel Fouled
Detonation
Oil Fouled
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