How To: Ford CMP "Blitz" miscellany

[Jacques Reed]

Originally Posted by Tony Smith

I made some of these up a few years back: http://www.mapleleafup.net/forums/showthread.php?t=4818

I noted at the time that there is a variation in spark plug gap .025 and .030 on different plates. Never got a response on why the difference.

Tony,

I found in the attached pages from the British War Department "Special Pattern Vehicles" Two types of spark plugs are specified. Champion J-9 and Champion H-10 both with different 0.025" and 0.030" gaps respectively.

It also appears that at some time the plug type was changed in the parts lists.
Both a 1940 parts list and a 1943 parts list show part No. 52-12405 C as the earlier part and 01T 12405 a later part to be supplied when 52-12405 C is depleted. 01T 12405 is also specified in the 1943 parts list as a Champion #H-9.

"J" plugs have a 3/8" reach with the 0.025" gap
"H" plugs have a 7/16" reach with the 0.030" gap

Not sure why but for some reason they changed the type of spark plug to be used.

Cheers,