Petrol Engine Info

This is a listing from the Champion Sparking Plug Co's handbook, published in 1956. There are also a couple of older charts which we hope to add on at a later stage to give a coverage from 1930 onwards. This is another long listing which will take a few weeks to input, so keep an eye open for the latest issue. This notice will be deleted when the listing is complete. The choice of listing order is taken from the handbook.

Heat ranges are illustrated by reference to the L-10 plug which is in the middle of the temperature range. Plugs are listed as above or below the L-10 or the next in the temperature sequence, with Hottest and Coldest being the extremities of the range.

Champion Plug Chart

Plug Type	Thread Diameter	Body Hexagon	Plug Reach	Gap Setting ***	Temp Range	Terminal
Type L-10	14mm	13/16"	1/2"	0.018" to 0.020"	Medium	A 548
Type L-10S	14mm	13/16"	1/2"	0.018" to 0.020"	Colder than L-10	A 548
Type L-11S	14mm	13/16"	1/2"	0.018" to 0.020"	Colder than L10S	A 548
Type N-8B	14mm	13/16"	3/4"	0.018" to 0.020"	Hotter than L-10	A 548
Type NA-8	14mm	13/16"	1/2"	0.018" to 0.020"	Same as L-10S	A 548
Type J-8	14mm	13/16"	3/8"	0.018" to 0.020"	Hotter than L-10	A 548
Type J-12	14mm	13/16"	3/8"	0.018" to 0.020"	Hottest	A 548
J-6 (Was J-10 Com)	14mm	13/16"	3/8"	0.018" to 0.020"	Same as L-10S	A 548
Type NA-10	14mm	13/16"	3/4"	0.018" to 0.020"	Colder than L-10S	A 548
Type L-8	14mm	13/16"	1/2"	0.018" to 0.020"	Hotter than L-10	A 548
Type N-7	14mm	13/16"	3/4"	0.018" to 0.020"	Hottest	A 548
Type H-10	14mm	13/16"	7/16"	0.018" to 0.020"	Same as L-10	A 548
Type Y-6	10mm	5/8"	1/4"	0.018" to 0.020"	Hotter than L-10	JA 548
Type 7	18mm	1"	1/2"	0.018" to 0.020"	Same as L-10	A 548
Type 15A	18mm	7/8"	1/2"	0.018" to 0.020"	Hotter than L-10	A 548
Type 16	18mm	7/8"	1/2"	0.018" to 0.020"	Same as L-10S	A 548
Type 17	18mm	7/8"	1/2"	0.018" to 0.020"	Colder than L-10	A 548
Type 11 Com	18mm	1"	1/2"	0.018" to 0.020"	Hottest	AB 146
Type 8 Com	18mm	1"	1/2"	0.018" to 0.020"	Hotter than L-10	A 146
Type 7 Com	18mm	1"	1/2"	0.018" to 0.020"	Same as L-10	A 146
Type 7 Com-L	18mm	1"	5/8"	0.018" to 0.020"	Hottest	AB 146
Type D-8	18mm	1"	11/16"	0.018" to 0.020"	Not Listed - Colder	A 146
Type 20 (Was 22)	7/8" SAE	15/16"	5/8"	0.018" to 0.020"	Hottest	A 146
Type I Com	7/8" SAE	15/16"	5/8"	0.018" to 0.020"	Hotter than L-10	A 146
Type C-5	7/8" SAE	1- 1/8"	5/8"	0.018" to 0.020"	Hottest	A 446
Type XL-10	14mm	13/16"	1/2"	0.018" to 0.020"	Same as L-10	A 548
Type XN-8B	14mm	13/16"	3/4"	0.018" to 0.020"	Hotter than L-10	A 548
Type XJ-8	14mm	13/16"	1/2"	0.018" to 0.020"	Hotter than L-10	A 548
Type X-7	18mm	1"	1/2"	0.018" to 0.020"	Same as L-10	A 548

NOTES: Terminal TypeA548 is the standard push-on modern type. Terminals A146, A446 and AB146 are the knurled type for holding on an ignition HT lead with spade end. Plugs prefixed with X are suppressor types. *** Plug gaps quoted are for Magneto ignition systems.

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