A Riley engine Mystery?

Many years ago in the very early 90s I was working with Barrie Gillies in Reading, Barry as most Riley people will know had probably the World's largest collection of Riley parts and a massive knowledge of Rileys.
While organizing the second hand parts stores that Barry had I came across a very similar engine but a 6, and there were two of them. Partly dismantled and talking to Barry about these he informed me that he had bought them from the late John Treen, A profound and very famous Riley special builder, Apparently these two engines were built by him as a development project and the idea was once tested as seperate 6 cylinder engines, was to bolt them both together on the sump flange and make some form of flat 12. (I think this would have been rather cumbersome but at that stage the 12 was only an idea) Barry had picked up all of John's spares when he closed his business.
I think by the looks and similarity of this 12/4 that it is the work of John Treen, unfortunately I have no pics of the 6 cyl engines but I have a very good technical memory and the similarities are large.
Fun project, good luck.
Julian

too much original left in the job for anything to do with Bugatti owners these days.

I think this engine has been converted to overhead camshaft from the original high cam with push rods, although it seems a lot of unnecessary work just to achieve this. I wonder perhaps if rotary valves were being tried. I hope you give us some photos when dismantled.

It does have 2 distributors but they each have only 2 plug wires. Must have been motorcycle units.

I remember Barry Peerless showing me that engine. As we understood it, the Riley Nine valvegear was quite capable of running to any speed required of it, hence we agreed was a rather pointless exercise.
As the photos show, it is a twin overhead camshaft conversion and although it does have two distributors, the standard Riley Nine cylinder head that's beneath it all only has one plug per cylinder.

wonderful piece of kit.Just my sort of thing.I bet a Bugatti owner made this.