Dar,

As you well know, there are many variables in running a model airplane engine. That's why the engines have needle valves and there are many different glow plug, fuel, and prop manufacturers.

Before anyone makes any quotations, it would be best for them to take these many variables into consideration.

You were not standing beside the engine with BLW and me the day that the OS #3 recomendation was given. If you were, then I'm sure you would have had the same recomendation as I did. Especially if that was the alternative you had in your flight box. Also considering that the engine then ran well with no pinging and it also ran well again yesterday when the temperature was 86 degrees...

There may be a time in BLW's future that he has to use a different plug than the #3? But the #8 was far too cold for his engine that day.

Enjoy,

Jim