AC 45B spark plugs

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Can anyone here tell me what a "series gap" spark plug is?  Found these old AC 45B plugs at an old parts place, and they cross reference to a Champion J8C, so they should work in the AC tractors that use a 45 plug.  These are really old plugs, I'd say from the 50's or earlier.  Might be worth looking for at old automotive job shops, but the "series gap" puzzles me.

	This site is not affiliated with AGCO Inc., Duluth GA., Allis-Chalmers Co., Milwaukee, WI., or any surviving or related corporate entity. All trademarks remain the property of their respective owners. All information presented herein should be considered the result of an un-moderated public forum with no responsibility for its accuracy or usability assumed by the users and sponsors of this site or any corporate entity.
	The Forum	Parts and Services	Unofficial Allis Store	Tractor Shows	Serial Numbers	History

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
TedBuiskerN.IL. Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Davis, IL. Points: 1959	Post Options Post Reply Quote TedBuiskerN.IL. Report Post Thanks(0) Quote Reply Topic: AC 45B spark plugs Posted: 11 Jan 2011 at 11:09pm
	Can anyone here tell me what a "series gap" spark plug is? Found these old AC 45B plugs at an old parts place, and they cross reference to a Champion J8C, so they should work in the AC tractors that use a 45 plug. These are really old plugs, I'd say from the 50's or earlier. Might be worth looking for at old automotive job shops, but the "series gap" puzzles me.
	Most problems can be solved with the proper application of high explosives.

Sponsored Links

JC-WI Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 11 Sep 2009 Location: wisconsin Points: 33652	Post Options Post Reply Quote JC-WI Report Post Thanks(0) Quote Reply Posted: 11 Jan 2011 at 11:39pm
	Some plug manufactors had a set gap for certain plugs... Yes, one is suppose to check the gaps and set according to engine manufactors specs. AC plugs had lots of definitions but the 45 is the heat range. Check to see if these plugs are 14mm or not. Did not find anything on a 45B. 45C was a commercial plug..which they had a threaded top to tight the spark plug wires under..used in old tractors, industrial engines etc., 45 S had a length that wa not threaded at end of plug past the threads, XL means extended reach, There are other definitions that were used over the years but lot of those plugs are considered obsolete now so are not supplied by manufactors anymore...specially the ones that one to china to have them made. Don't know if its true or not but somebody said that AC plugs are now bought from champion that has a facility across the waters. If the base does not have the old AC knurled ring around the base, its foriegn made. (I can't prove that statement but the last AC plugs I bought were smooth and did not say made in USA on them)