Valve Lapping/Grinding

[Grahammf]

Hi guys,

I've dropped the engine out and taken off the head to change the head gasket, and while it's out i thought i may as well lap/grind the valves. Inlet's are all done fine, but exhaust valves are too small for the hand grinder (standard one from halfords) to get proper suction, so i was wondering if anyone had done this recently and had any tips on how to do them easily?

Thanks

Graham

[masterofinsanity]

Mori Man is the man in the know see his thread here

[cargo]

I put a bit of rubber pipe on the valve and do it sort of back to front

[Grahammf]

I put a bit of rubber pipe on the valve and do it sort of back to front

sounds promising...could you elaborate a bit please?

[cargo]

Well what I have is an old screw driver with a short peice of rubber pipe on the end of it with a couple of cable ties to secure it. The end of the pipe then fits over the end of the valve after I've put it in position with a little grinding paste on the seat. Then I lap the valve in using the screw driver in the same way you use a normal lapping rubber sucker thingy.
Except I need to maintain a light pull on the screwdriver rather than a light push.

The rubber pipe needs to be a tight fit on the valve and a cable tie can help keep it in place the pipe twists a little but it seems to work OK.................it's a little strange at first but it works for me.


A real lazy way to do it is use a drill and grab the end of the valve in the chuck.........................................but I'd not recommend it

[extonyg]

i have a little bar of metal that i put in a drill with a bit of rubber pipe and use that to lap valves in on cars so same priciple, but just dont go too mad with the drill.always go up and down so the valve lifts off the seat and back on again (if that makes sense) laps in better this way.hope this helps