Frank, I don't know if you
Frank,
I don't know if you already know about this, but it looks like GM will also have a patent on a split-cycle engine that has the compression and power cylinders on separate shafts. (If you search 'Google Patents' for '12/724461', you can view the patent application.). Their design also includes an 'expander' cylinder, presumably to extract energy out of the combusted gases before they go out the exhaust. (This is apparently the 'discrete-compression/discrete expansion' concept Alan Taub from GM mentioned last Ocotober.)
According to the US Patent and Trademark Office website, GM was mailed a 'Notice of Allowance' for this patent application on 5/29/12. (You can view the transactions for this patent application at the 'USPTO Public PAIR' site. When you get to the ‘Search for Application’ screen, enter the application number ’12/724461′. )
I don't know if GM has prototyped this engine, or whether it only exists on paper or in simulations. They showed at least some interest in the split-cycle concept in getting this patent, but I wonder how much they are going to pursue it?