Question

Knurling is:

O reaming the guide oversize and using a valve with an oversized valve stem.
O when a bit with a spiral groove is threaded through or run through the valve guide.
O installing a thin-walled aluminum liner.
O installing a thick-walled guide that is made of aluminum.

Answer 1

Knurling is:

O when a bit with a spiral groove is threaded through or run through the valve guide.

In engine building and machining, knurling is a process used to create a pattern of diamond-shaped or straight-line ridges on the inner surface of a valve guide or other cylindrical parts. This pattern provides a rough texture that can help retain oil and improve lubrication in certain applications, such as valve guides.