Glossary “interference angle” Definition:
The difference between the valve face angle and the valve seat angle.

Glossary “interference engine” Definition:
An engine that will experience piston-to-valve interference if the timing chain or belt slips or breaks. Also called a non-freewheeling engine.

Glossary “interference fit” Definition:
When to parts have a pressed fit.

Glossary “interference valve angle” Definition:
The difference between the valve face angle and the valve seat angle, usually one or two degrees.