911 - 964 - 993 - Turbo - RS - Cup cylinder head revisions Porsche

911 - 964 - 993 - Turbo - RS - Cup cylinder head revisions Porsche.

An AMS cylinder head revision includes the following work:

• Check cylinder head for cracks
• Clean the cylinder head pore-deep using the shoot peening process and compact the surface
• Press out damaged intake and exhaust valves, drill them out if necessary
• Re-drill and fine-hone the valve guide bore
• Turn oversize valve guides to overhang dimension
• Heat the cylinder head in a convection oven
• Press the dry ice cooled valve guides under high pressure
• Valve guides at 90° to the valve plate - honing and fine-honing the contact surface
• Milling or fine turning the cylinder head flat surface.
• Milling existing valve seat rings at 3 angles with 3 different steps
• Compress valves using the shoot peening process on the plates
• Regrind valves in 3 stages on the valve plates
• Re-grind valves onto the valve seat(s)
• Measure and adjust the immersion depth of the valves
• Valve stem - Install seals on the valve guides and valves
• Check valve springs and adjust and install with required preload
• Install valve cones to fix the valve plates to the valves