An observation I forgot to post earlier. When I removed the Bosch Platinum
plugs I had in my car I found the gap had narrowed from 35 to 30 thou!
All my previous plug experience has shown the gap will increase with wear.
I found no deposit buildup to account for this narrowing of the gap. It
almost appears that the outer electrode had "sprung back" from heat fatigue.
Possible? I'm pretty fanatic about setting and checking gaps at tuneups, so
I really doubt i neglegted to set it in the first place. Also, the plugs out
of the box are gapped to .030 and they appear to be perfectly parallel to
the center electrode surface (I know it's a cone in the platinum's)with the
outer electrode making a perfect right angle bend. When gapping I had to bend
the side of the outer electrode-outwards, and then the top-down, to get a
parallel .035 gap. When examining the plugs after removal the top electrode
appeared to have drooped (@.030 gap).
just an observation,
-Bob T.
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