Rotary valve engines

About twelve years ago, I read an interesting article about a typical V8 that had been retrofitted to run using rotary valves instead of the usual poppet valve and camshaft arrangement found in just about all internal combustion engines. If memory serves, the engine was able to rev to around 15000 rpms, make much more power and run much more compression than it had in its previous configuration. It sounded great but then they kind of dropped out of the picture.

Fast forward about a decade... A year or two ago, that article came up in conversation with some friends and so I started looking up rotary valves again and stumbled across the site of Coates International Ltd. At the time, they appeared to be doing a bunch of R&D and had patented a very slick looking rotary valve setup, the Coates Spherical Rotary Valve Engine" (CSRV). I visited the site again today, and was delighted to see that they have received 10 million dollars in funding and have recieved many orders for their complete CSRV engines.

To summarize the benefits of the CSRV, here is an excerpt from their site:

The CSRV engine design eliminates the use of poppet valves, springs, rockers, camshafts, pushrods, etc. In fact, the CSRV system removes most moving parts from a standard industrial 855 CID engine, including the engine oil from the top part of the engine, replacing all these parts with only two moving sphere shafts, twelve floating seals and carriers that require no oil, no servicing or adjustment, producing higher volumetric efficiency, allowing higher compression ratios to be utilized. This results in an engine possessing higher thermal efficiency, lower emissions, and higher M.P.G.s.

In a video interview with CEO George Coates posted on their site, he states that the engines will have close to twice the volumetric efficiency of a conventional poppet-valve motor, be able to run much more compression, make more power, have almost no emissions and never need an oil change. He said once they have the orders filled for the entire engines, they will look into developing retrofit kits for popular V8s.

I'm excited about the possibilities!