Summary

00:00 - Logan has asked, I've always lapped valves using a drill and a hose connected to the new valve with compound and brought the valve up and down to the valve mating surface in the cylinder head.
00:10 Is there any other at home methods that are recommended.
00:14 OK Logan I'm sorry to disappoint but lapping valves like that is actually a surefire way to actually get really poor valve seating.
00:24 Now what it's going to do is give you great valve seating when you are testing at room temperature.
00:31 But the problem with using a valve lapping technique like that is that what it does is it creates a convex and a concave surface, one on the valve, one on the valve seat which essentially ensures that the only time that valve is going to set properly is when it's cold.
00:46 As soon as the valve heats up when the engine is operating, it's going to move slightly or expand slightly and the convex and concave surfaces aren't going to line up properly.
00:56 So this is a technique that really isn't utilised anymore.
00:59 The process of cutting new valve seats is one that really is best to leave to your engine machinist, it requires some specialist equipment to do it properly.
01:07 Valve lapping still has its place but generally it's used with a very fine valve lapping or grinding paste and just a few light turns with the valve lapping equipment and instead of trying to get the valve seating correct or correct errors or problems with the valve seating, we're using it more just to visualise the valve seating, making sure that our valve seats are in good condition and we're getting good contact with those valve seats.
01:34 So something to be really careful of there.
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