Stock Spark Plugs - heat range?

WarmAndSCSI

And BTW, stock plug gap spec seems to be 1.1 mm (0.043 in), which is actually pretty wide for a high compression engine. That said, you probably couldn't gain any power by opening that up at all. And I doubt you'd regain any power by closing it up (assuming any spark suppression is present at all with our COP system).

edit: oh, and on the oil temp idea: really, the oil temperature elevation on these engines is testament to how well the oiling system is carrying away extra heat from piston skirts, bearing surfaces, wrist pins, etc. under high load. The temperature in the combustion chamber is most directly related to coolant temperature, and I haven't heard of anybody reporting that ever spiking. Besides, 240-260 degrees isn't that hot as far as oil goes. Air-cooled Porsche engines were sustaining much higher oil temperatures back when automotive oil technology was relatively primitive.

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