A friend of mine had two carburetors damaged when his plane went into the ground nose first, while using a small spinner nut. My plane hit the ground nose first from a height of forty feet. I had to pull the engine out of the ground where it was embedded four inches deep. No damage to the engine or carb as the large plastic spinner displaced the dirt around the carb rather than through it. I am guessing that the plastic spinner absorbed most of impact before being destroyed, thus limiting the amount of damage.