Champion X plug gap for high altitude?? I bought some N.O.S. plugs and was wondering what the proper gap should be for high altitude, stock engine.
Same as any other altitude. I don't have a great photo of the wrapper, but if you read one carefully you will see that Champion recommends .025" gap for the X plugs. That's always worked fine for me, anywhere, any temperature and at any altitude.
a worn dime's worth
A dime hasn't been a good plug gap gauge since 1965. Got to be a worn out silver dime !
Rich is right, I shoulda been more spec specific: a worn MERCURY dime!
Paper clip is the standard for plugs and coils and easy to carry on your key ring.
The A-15 type X plugs you have should be fine at high altitude. Having said that, some suggest it's a good idea switching to a hotter plug (Champion 30 or 31) for high altitude conditions.
Love the "Two Piece Heavy Stone" ad on the wax paper. They did come in 1/2" pipe but were double the price of the X.
A great plug gapper
In 1921 the "Heavy Stone" Model T plugs were a dollar. The regular Champion X plugs were 75 cents.
The "Heavy Stone" plugs say Champion Toledo on them in black letters, and had a brass top several years before the X plugs did.
Not all Heavy Stone plugs had "Toledo" on them.
Neat pages ! I always wanted a set of those green insulator Splitdorf plugs to run on my T. Even the name is super kewl !!
So this is not a very hot plug and may not perform very well at high altitude?
That is a great plug for any altitude.