Work on the cylinder head rebuild. Drakes of Bradford refaced the head and manifold faces and fitted hardened exhaust valve seats (Exhaust on the left, for those not mechanically minded, the inlets are always larger than the exhaust valves)
Below is the tool for cutting the inlet valve seats. They were in good condition, so this is just a light cut before "lapping in"
Below, John cutting a seat, The mandrel must be a perfect fit in the valve guide to ensure a straight cut. The drive "spring" between the drill and the mandrel ensures no side load from the drill is put on the stone / valve guide.
Below you can see John "lapping in" a valve, using an air tool that oscillates the valve head. This used to belong to my Grandfather, who was using it when my father was a little boy and he is 85!
All valves done, not quite, the two with a X on needed a third grind. To check the seal, valve springs were fitted and ports filled with brake cleaner, very very searching. No leaks mean an air tight seal.