valves lapped into head??????

[Paddy_g46]

what does this mean can any1 tell me?

 

[Fred@BTM]

i'm not an engine builder, but basically it means the valve is perfectly matched into the valve seat so a total seal is formed

simple process, but takes ages

BenR will no doubt give you the full "geek" description

 

[Paul C]

as fred said its just so the valve has a perfect seal onto the head.

 

[BenR]

lapping in the old sense of using coarse, medium then fine grades of paste is a bad idea, it leads to a fubar'ed seat.

Lapping now should only ever be a 5-10 second affair per valve to ensure valve seat from a fresh seat cut.

I would never lap an old seat, always get them recut.