Thinking of Platinum+2 spark plugs Options

[Porschef]

They're supposed to burn a little better. Also considering jumping up one heat range.

Any suggestions welcome, thanks.

Joe

[Jeffs9146]

I tend to drive mostly around town, and seem to get fouling.

This indicates you should step up to a hotter plug maybe a BP6ES! This is what I ended up doing on my 67 911 and it ran MUCH better!

Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.

[Cap'n Krusty]

I tend to drive mostly around town, and seem to get fouling.

This indicates you should step up to a hotter plug maybe a BP6ES! This is what I ended up doing on my 67 911 and it ran MUCH better!

Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.

A B6 is a bit hot, 2 heat ranges hotter than the original specs. And early 911s don't use extended reach plugs. What you really need to do is install a CDI like the factory did ..................

Edit: Lemme rethink that. With "modern" fuels and Weber or Zenith Solex carbs, an NGK 6 is probably necessary, even with a CDI setup. Extended reach plugs are still questionable. The original plugs are of a design that's NLA, and they were sort of half way between a standard reach and an extended reach design.

The Cap'n