I like this trio of videos because Smitty makes all the little details of valve design, maintenance, and performance modifications come together so simply.
The goal for engine valves is to be air tight.
Specs for Air Tight Valves
Smitty walks through the essential specs of poppet valves in most engine today, for both intake and exhaust: (1) contact angles, (2) sealing bandwidth ratios, (3) thick radius edges, and (4) surface finish.
8 Basic Steps of a VJ
The valve job process starts with how to diagnose a leaky valve using simple equipment, then how to examine the valve sealing contact area with a blue Sharpie. Smitty gives a high-level overview of the process to clean, repair, and then test a valve seal before throwing the engine all back together, again with simple equipment.
High-Performance VJs
One of my favorites! Smitty connects the details of high-performance valve jobs with the fundamentals of aerodynamics. Simply knocking off some corners to make a multi-angle valve seat and back-cutting the valve.
