Chris Kennedy wrote:

While much of it will eventually
come pouring out the air cleaner it's not hard to imagine getting
unlucky and having one cylinder with an intake valve open.

In any engine that has valves and at least four cylinders, at least one of the intake
valves will be open when the engine is not running. In a four-banger, there will be
one piston on the power stroke and another on the compression stroke, and these two
pistons will stop about halfway down the bore (where the compression in each is about
equal). One of the other pistons will be halfway down the intake stroke.

George Patterson
I childproofed my house, but they *still* get in.