i used to do this a long time ago ,but i also dressed the stones of the seat grinder by running the diamond on them ,using an arbor in the lathe chuck .Using blue on the seats showed a new perfect fit ,with no lapping required.
Very nice setup, just a different way of doing things but a trick I learned from an old engine builder is on a 45 degree seat cut the valve face to 44.5 degrees which works as an interference fit improving valve seal in extreme high stress engines. Just thought I'd share
I've cut valves with a cutter and it works close enough that you can lap them in and get away with it on something like a briggs. I cut one on my lathe once just to see how close it would get and then stuck it in my friends valve grinder and according to that it only took a little over a quarter thou to clean up.
Beware worn valve stems that make the valve rotate off center, if you place the stone next to the valve head and turn the chuck by hand you may be able to chuck the valve in or out, or rotate the valve in the chuck until you get the chuck jaws off the worn spot. Check to see if the unworn machined surfaces are concentric with the valve stem as an additional check. You can also mike the valve stem all over checking for wear. On the other hand, everything may work just fine first try with no fiddling, LOL.
Thats good, how the end result is. So a dedicated valve grinder/resurfacer is not really necessary for a hobby home mechanic, as long as you have a lathe???
Thanks for all the great vids. I have learned a lot. How do you repair the seat? cutter or grind? Also have you ever tried to boar a small engine cylinder on your lathe? I have some old Gravelys and a South Bend heavy 10 Thanks Rob.
I know I'm a bit late to the party Mrpete being that this was posted over 10 years ago, but why were you unable to use coolant? I understand flood coolant being a problem, but a mister or even KoolMist in a spray bottle would have been better than nothing. Just a curiosity. I found your channel about a month ago and have since started watching all your videos from the beginning......when you first started posting. Do you have an email I can send you some pics of a strange tool? Thanks.