THE FOUR WAY SLIDE
We often times trust our senses. I trust my sense of touch in what I call, The Four Way Slide. The bounce test works, but this concentricity test tells you more. I slide the valve against the seat to the back, right, left, and back towards me. If the feel and movement is the same, the seat is very concentric to the valve guide. I manipulate the valve stem at the spring side with my other fingers and with practice its second nature. I always check each one when I’m cutting the seats. If it isn’t good, I influence the spindle on the Serdi or VGS20 toward the side with the biggest slide while floating to the center the spindle. If it starts cutting on what you found was the high side of the slide, it’ll be better.
Randy Torvinen
Torvinen’s Machine
Menahga, MN
FEBRUARY, 2024