After reading Swoft’s post above I decided to e-mail Larry Brumfield to see what he had to say about his previous spark plug info concerning the Champion W-16Y. As a rebuilder of Model A engines to precise standards we are always interested in info from more than one source that we can pass along to our customers and also make comparisons to our own experiences.
Here’s what Larry said in his e-mail:
Hello Mr. Gulbankian, long time no hear:
Thanks for sending me a copy of the Ford Barn thread for my review.
The info that I provided in the past on message boards about the heat range of the W-16Y came DIRECTLY from the Champion Spark Plug catalog/manual provided to our local auto supply. I also went to 3 other auto supply stores and they all had the exact same book. This was Auto Zone, O’Reillys and Advanced Auto; 3 national big chains. Afterwards, even though I have had considerable experience in the past during my flat track days and also with Model A/B with projected nose plugs, I decided to see what the present day Champion people had to say about it concerning Model A’s. So I called the Champion Spark Plug company and finally got to speak with one of their spark plug engineers and he explained how a projected nose spark plug works.
According to the Champion engineer, whom I’m sure would have more insight than myself or Swoft, the W-16Y does not get hotter at 5500 RPM but gets cooler! ... which is the opposite of what Swoft is saying in his post.
According to the Champion engineer, a spark plug with a projected nose (like the W16Y, the Y stands for standard projected nose) has a broader heat range. The core nose is longer and projected into the chamber with open exposure which provides a "hotter" plug at low speed, as compared to an exact same plug with no projected nose, and helps to prevent fouling. As the engine speed increases, the incoming air/fuel mix flows across the exposed tip of the core nose, providing charge cooling which effectively reduces heat range at higher speeds.”
So I asked the Champion engineer at what higher speed? He replied, “Much higher, at say 5500 RPM or so.” So I said 5500 RPM is not foreign to my past with race engines, both auto and motorcycles, but that really does not apply to most Model A ers. He said, sorry, but that is the nature of a projected nose plug.
Apparently, Swoft does not realize that some Model A’s run leaner than others and people get different results with the same spark plugs and also some drive them faster, as a routine, than others which also affects the plugs. Moreover, some allow long periods of idle and others will turn their engines off to avoid it. Collectively, and as a result, some W-16Y’s will run cooler, a little too cool, while other W-16Y’s on other engines appear to be a normal heat range and a good color. Personally, I’m not a fan of the W-16Y but for Swoft to make a blanket statement and imply that a W-16Y is automatically going to foul out for everyone is just bogus and uninformed.
Best regards
Larry Brumfield