grinding in new valves

[jonn]

anyone know much about grinding, lapping in new valves?

how long should you spend on each valve and what should the finish look like smooth or lines on the valve?

[Steve0011]

the finish should be a dull grey finish about 2 or 3mm wide, i assume you mean grinding in with paste? use course paste followed by fine. using the sucker on a stick method can take 10-20 minutes per valve, i use a rechargable drill on a lowish speed putting the chuck on the valve stem, this method speeds up the process but you HAVE to make sure the hold the drill straight and true or you can bend the stem.

hope this helps :)

[swedge]

the finish should be a dull grey finish about 2 or 3mm wide, i assume you mean grinding in with paste? use course paste followed by fine. using the sucker on a stick method can take 10-20 minutes per valve, i use a rechargable drill on a lowish speed putting the chuck on the valve stem, this method speeds up the process but you HAVE to make sure the hold the drill straight and true or you can bend the stem.

hope this helps :)

exactly what i do :)

[jonn]

ya i have the paste coarse and fine, i have the stick with the sucker so i will try that and see how i get on. thanks

[philip]

just look for an even smooth grey line but you need to rotate back and forth not just one direction and also move the valve around too. i prefer lapping valves in by hand compared to an machine tool as you get a better feel...also listen out for note change too...you will probably find that you only need fine pate for inlets as the seats are usually very good anyway, its the ex valves that tend to pit slightly, sometimes it may be worth getting the valves or seats or both refaced for the exhaust side depending on the wear on them