Ford Experimental Aluminum V8 Cylinder Head Gasket Design - O-Ring Seal, Fig 23-24

This is page 15 of a Ford engineering/technical publication describing an experimental engine's cylinder head gasket design. The large illustration (Figure 23) shows a cutaway of the head-to-block sealing arrangement, with callouts identifying a section through the metal "O" ring that seals each cylinder bore, rubber "O" rings at the water transfer holes, and a .012-inch air gap between the head and block faces. The accompanying text explains that sealing allowance was made for two oil drain-back holes and one oil pressure hole at the front, plus two water transfer holes and one oil drain-back hole at the rear, all sealed with conventional rubber "O" rings. The metal "O" ring around each cylinder carries the full concentrated load from the cylinder head studs, creating a 0.010 to 0.015-inch air gap between the block and head faces. The text further notes that the cylinder heads (shown in the Figure 24 photographs) were sand-cast aluminum made from reworked experimental 260-engine patterns, featuring aluminum bronze valve guides, hardened steel valve seat inserts, and steel valve spring seats. Readers learn how this experimental gasketless O-ring sealing system worked and the construction details of the aluminum cylinder heads.