28-07-2018, 09:48 PM
These are handy devices but dangerous in the hands of amateurs. Once gone metal cannot be put back. Ideally confined to narrowing seats and cutting for oversize valves.
For decades I ran a Javelin which cars for various reasons are prone to recession, so had to regularly recut for oversize valves etc. I made a simple single cutter version which is operated against a stop.
Valve grinding is now questioned. Any attempt to correct the seat leaves a groove in the valve. I made up a set of shafts with mild steel heads attached. These are selected to close fit in guide and used as laps and regularly set to run true and corrected in the lathe. As with new cars valves then not reground.
For decades I ran a Javelin which cars for various reasons are prone to recession, so had to regularly recut for oversize valves etc. I made a simple single cutter version which is operated against a stop.
Valve grinding is now questioned. Any attempt to correct the seat leaves a groove in the valve. I made up a set of shafts with mild steel heads attached. These are selected to close fit in guide and used as laps and regularly set to run true and corrected in the lathe. As with new cars valves then not reground.