This is a interesting valve seating video.. My thoughts on valve lapping - YouTube

I have done the grinding with paste method many times but this guy shows how it is done with his own grinding past formula.

The old timers used to use a lead pencil and mark a vertical line on the seat face every 90 degrees, insert the valve and rotate it slightly , pull out the valve and look for the pencil marks to be broken.

You only want to remove the minimal amount of seat , if the seat becomes too deep and wide you have to install inserts or buy or make oversize valves.

I had a 1946 Dodge ute years ago and somebody had messed up the seats, widened/deepened the valve seats far too deep , the standard valves were useless , they would not seal at all.

Somebody mentioned to me it would be possible to weld a new face onto a worn out valve and re-grind the face back .

I have cleaned up Holden red motor valves in a lathe , the alloy is machinable.


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