There is much wear to the club exhaust valve stems if placed in iron guids, they have strange lines and are battered after only 5000km even in a side valve.
Who has the same experiëns?
If an exhaust valve is placed in the inlet, the same wear is seen.
As an experiment I have welded a new valve disc to an old stem, result; no wear at all !!! (there are valves made this way, the stem magnetic, the disc not).
So are the new valves only fit for bronse guids?