Valve job on os valves

What people don't realize it that when machine shops talk about "three angle" valve jobs, they're not talking about anything special. Every single automotive and light truck engine from our era came with a three angle valve job. That's a stock factory valve job. Machine shops have cut that corner for DECADES acting like when they grind or cut a three angle valve job, you're gettin somethin special, when you're not. They grind or cut a simple single angle for the speed of gettin it done and out the door and lower total cost. You can verify this easily in most any factory service manual that details a factory valve job and gives an explanation of those angles. Most shops refer to it as a "competition" valve job, but there's nothing competition about it, although certainly it takes more labor to do.