This 1920 Napier has a B_^&T-built two-piece aluminum billet Water-Cooled Cyl. Head. This billet cylinder head is a complete B_^&T “in-house build.”

The two-piece billet Cyl. Hd. is a “Roberts Auto Design Consultants” creation. The original ports, head bolts, and cooling passages are asymmetric. Rick Roberts created new int. & ex. ports. He designed the entire water passage system.

We use the C.A.D. files to 3D-print a two-piece plastic model Cyl. I digitize this “model” to create C.N.C. tool path. I use this “tool path” to machine a complete two-piece Billet Cyl. Hd.

Rick Roberts redesigned the intake and exhaust ports. Rick made all the ports symmetrical. He made the new water cooling passages symmetrical. Think about that. Rick’s CAD model has the locations for the bolt holes, valve train ports, etc.

The original “intake manifold” and plenum are a poor design. The new two-Piece Billet Cyl. Hd. has a good intake plenum design. Rick sent a “complete single cyl.” C.A.D. file to Darren @ LS brackets. (Darren is XRV10 LS engines.) Darren made a blue plastic 3D print model of the new Napier Cyl. Head.“ This 3D plastic model is an exact copy of a single Napier cyl.

I digitized all sections of this plastic model. We used this C.N.C. machine “code” to machine the two billet halves. I assembled both halves.

The two-piece Billet Cyl. Head pressure tests to 125 P.S.I. Roberts Auto. Design Cslts. uses a C.F.D. program to provide valve job specs. Paul Tester did the valve seat and guide work.

I will post more 1920 Napier Billet Cyl. Head pics and videos.
I can build anything you want. What can I build for you?