Page 815 - 2019-2020 Racecar Engineering Circle Track Parts and Accessories Catalog
P. 815
SPARK PLUG HEAT RANGE/CROSS REFERENCE
Thread Heat Standard Non-Resistor Spark Plugs Power/Projected Tip Non-Resistor Spark Plugs
Size/Reach Hex Range Autolite Champion NGK Accel Autolite Champion NGK
Chevrolet, Chrysler (Wedge), Oldsmobile, Pontiac - Standard Reach - Flat Seat With Gasket
Hot — — — — — — NGKR5670-5
— — NGKB6S — AUTAR73 — NGKR5670-6
14mm/3/8" 13/16" AUT353 CHPJ4C NGKB7S — AUTAR72 CHPJ63Y NGKR5670-7
— — NGKB8S — — — NGKR5670-8
Cold — — — — — — NGKR5670-9
Chevrolet (Big Block), Chrysler (Hemi) - Flat Seat With Gasket
Hot AUTAR3935 CHPC63CX NGKR5671A-7 — — CHPC63YC —
AUTAR3934 CHPC61CX NGKR5671A-8 — AUTAR3911 CHPC61YC NGKR5672A-8
14mm/3/4" 5/8" AUTAR3933 † CHPC59CX NGKR5671A-9 — AUTAR3910† CHPC59YC NGKR5672A-9
AUTAR3932 † CHPC57CX NGKR5671A-10 — — CHPC57YC NGKR5672A-10
Cold AUTAR3931 CHPC55CX NGKR5671A-11 — — — —
Chevrolet (Big Block), Chrysler (Hemi) - Flat Seat With Gasket
Hot — — — — - — NGKBP5ES
AUTAR2593 — — — - — NGKBP6ES
AUTAR2592 — — — AUTAR53 — NGKBP7ES
14mm/3/4" 13/16"
— CHPN59DR — — AUTAR52 CHPN59YDR —
— CHPN57DR — — AUTAR51 — —
Cold — — — — AUTAR50 — —
Chevrolet (Small Block), Ford (Small Block) - Conical/Tapered Seat
Hot — — — ACL0276S-4* — — —
— - NGKR5673-6 — — — NGKR5674-6
AUTAR135 CHPV63C NGKR5673-7 — AUTAR13 — NGKR5674-7
14mm/.460" 5/8" AUTAR134 — — — AUTAR12 — NGKR5674-8
AUTAR133 — NGKR5673-8 — — — NGKR5674-9
AUTAR132 CHPV59C NGKR5673-9 — — CHPV59YC NGKR5674-10
Cold — CHPV57C NGKR5673-10 — — CHPV57YC —
Chevrolet (Big Block), Ford - Conical/Tapered Seat
Hot — — — — — CHPRS9YC —
— — — — — — —
— — — — AUTAR94 — NGKR5724-8
14mm/.708" 5/8"
AUTAR474 CHPS59C — — AUTAR93 CHPS59YC NGKR5724-9
AUTAR473 CHPS57C — — AUTAR92 CHPS57YC NGKR5724-10
Cold - CHPS55C — — - — —
Ford (Windsor and Big Block) - Conical/Tapered Seat
Hot — — — — — — —
— — — — AUTAR33 — —
18mm/.460" 13/16"
— — — — AUTAR32 — NGKAP8FS
Cold — — — — — — —
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.
* Signifies “shorty” style spark plug.
† Special Autolite Racing “X” style electrode spark plug, which alleviates piston/spark plug clearance issues, is also available; add “X” to end of part number.
Spark Plug Diagnosis Pictures Courtesy Of Autolite
• 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.
• Inspect plugs and pistons for evidence of detonation, abnormal combustion, or
Normal Fuel Fouled Detonation Oil Fouled
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
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perative that the plug stay cool enough to prevent pre-ignition or electrode destruction, and still remain hot enough to burn off com-
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2019-20 CIRCLE TRACK PARTS AND ACCESSORIES 811
