Quote:
Originally Posted by ds190
My tiny brain does not understand. If warming metal expands it, then wouldn't that increase the friction between the metals (either aluminum or iron or both), and make it more difficult to remove the glowplug? I would think it a glowplig would come out the easiest after the car was left outside overnight in 30 degree temps.
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Aluminum head expands faster and more than steel glow plug body does. so the aluminum hole gets larger than the Steel glow plug.
most materials have differing rates of expansion. aluminum is a fast expander to heat. steel is also... water *(in the form of ice) actually shrinks with heat... odd.