Assertion: valve's stem | /r/HasProperty | small
Facets:
value: very
type: DEGREE
Source sentences:
text: Because the valve stem extends into lubrication in the cam chamber, it must be sealed against blow-by to prevent cylinder gases from escaping into the crankcase, even though the stem to valve clearance is very small, typically 0.04-0.06 mm, so a rubber lip-type seal is used to ensure that excessive oil is not drawn in from the crankcase on the induction stroke, and that exhaust gas does not enter the crankcase on the exhaust stroke.