kwisor
Senior Member
What is in your Model A Ford? How are your Plugs Burning?
Submitted by rlawson on Fri, 2011-07-15 22:04
The above picture shows a comparison of the replacement plugs with the Original 3X and a NOS C-4 porcelain (just for more reference). The BEST match for the Original 3X turns out to be the W18. The second is the TT10/3076, which appears to be a little better match with the C-4 and then the W16Y, which is the COLDEST of the plugs. Also note the hair crack in the above C-4 porcelain. This could cause a misfire plug.
The above picture shows a comparison of the W18, and the Original 3X with the 3077/TT11. As can be seen, the porcelain cone is significantly longer than the W18 which means it is a hot-hot plug which may be used for an oil burner or a rich runner. If you have a bad running car, the first thing to check is what plugs you have AND does it run a little rich (probably not very good mileage either). Try the W18’s.
Now the question is… How are YOUR plugs burning?
If your porcelain is…
WHITE…Too hot a plug
TAN/LIGHT BROWN…Just Right
BLACK…Too cold a plug
Recommended spark plugs for the Model A:
Reproduction. Champion 3X - $27
Champion W18 (Equal to Champion 3X - $13
Autolite 3076 (Hotter than W16Y) - $2.50
Motorcraft TT10 (Same as 3076) - $4
NOT Recommended for the Model A:
Champion C-4 (Ref. Ford S/B Aug. 1932)\
Champion W16Y (Equivalent to C-4) (Too cold) - $9
900 – 1500 deg. F. is the optimum heat range for plugs.
A 10 deg. spark advance from a particular advanced position will raise plug temperatures by 150 – 200 deg. F. For example assume that you have advanced the lever to a 20 degree advanced position and the engine is running at a certain plug temperature, then further advance the spark 10 degrees to a 30 degree advanced position (about full advance), then the plug temperature will go up an additional 150 to 200 degrees.
Spark plug gap for a standard compression Model A is .035". Reduce plug gap to .030” with 5.5 of higher compression ratio.
The insulator nose length of a Champion 3X is 0.875” - just right for the “A”.
Note: The reproduction 3X plugs have a terminal nut that is smaller than original; however, all the “A” supply houses carry the correct nuts for a few cents each.
Submitted by rlawson on Fri, 2011-07-15 22:04
The above picture shows a comparison of the replacement plugs with the Original 3X and a NOS C-4 porcelain (just for more reference). The BEST match for the Original 3X turns out to be the W18. The second is the TT10/3076, which appears to be a little better match with the C-4 and then the W16Y, which is the COLDEST of the plugs. Also note the hair crack in the above C-4 porcelain. This could cause a misfire plug.
The above picture shows a comparison of the W18, and the Original 3X with the 3077/TT11. As can be seen, the porcelain cone is significantly longer than the W18 which means it is a hot-hot plug which may be used for an oil burner or a rich runner. If you have a bad running car, the first thing to check is what plugs you have AND does it run a little rich (probably not very good mileage either). Try the W18’s.
Now the question is… How are YOUR plugs burning?
If your porcelain is…
WHITE…Too hot a plug
TAN/LIGHT BROWN…Just Right
BLACK…Too cold a plug
Recommended spark plugs for the Model A:
Reproduction. Champion 3X - $27
Champion W18 (Equal to Champion 3X - $13
Autolite 3076 (Hotter than W16Y) - $2.50
Motorcraft TT10 (Same as 3076) - $4
NOT Recommended for the Model A:
Champion C-4 (Ref. Ford S/B Aug. 1932)\
Champion W16Y (Equivalent to C-4) (Too cold) - $9
900 – 1500 deg. F. is the optimum heat range for plugs.
A 10 deg. spark advance from a particular advanced position will raise plug temperatures by 150 – 200 deg. F. For example assume that you have advanced the lever to a 20 degree advanced position and the engine is running at a certain plug temperature, then further advance the spark 10 degrees to a 30 degree advanced position (about full advance), then the plug temperature will go up an additional 150 to 200 degrees.
Spark plug gap for a standard compression Model A is .035". Reduce plug gap to .030” with 5.5 of higher compression ratio.
The insulator nose length of a Champion 3X is 0.875” - just right for the “A”.
Note: The reproduction 3X plugs have a terminal nut that is smaller than original; however, all the “A” supply houses carry the correct nuts for a few cents each.
But anyhow I've tried all sorts of plug types and I have the best luck with the Champion 3x