Valves

                  Inlet valve, very small amount carbon.                           Exhaust valve, 1 to 1.5mm thick carbon.

           Hold valve in drill, use cup wire brush mounted in angle grinder to remove carbon deposits quickly an easily. Be sure to wear safety glasses or its hospital experience. The wire in the finger could have been an eye.

                                                           Before and after inlet / exhaust

Valve grinding should never be rushed and with 24 of them I was expecting to spend literally days doing this job. Previous valve grinding that I've done were on cast iron heads where the seats were in pretty bad shape, I never managed to remove all the pitting before the seat width became too big.

The valve seats on the 24v are hardened inserts ( as are most unleaded vehicles ), these have stood up to the wear much better than I would have expected. I started with the exhaust valves as these are normally the worst ones.

Using only fine grit paste and a wooden valve grinding stick each inlet valve took an average of  2 applications of paste. A single drop of WD40 helped make things easy as the paste can be a little thick. Next were the inlet valves, most of these needed just one application of paste. There was just one valve where the seat was very slightly oval, this took just a little longer than the rest, otherwise everything was text book stuff. I managed to removed 100% of the pitting without making the seat widths oversize. The whole process took about 5 hours, after which time I could hardly feel the palms of my hands, the next day the bruising on my palms was quite visible and painful, I don't want to do anymore grinding for a while !