"C J Campbell" wrote
I merely point out that his theories are controversial -- they are hardly
universally accepted, as even this thread amply demonstrates.

A thread on usenet demonstrates no such thing. Evolution is hardly
controversial within the scientific community, yet it is debated ad
nauseam on usenet. Deakin's theories (which are really not his at
all, and not really theories) are really no more controversial - in
fact, they formed the basis of normal operating practice for piston
fighter and airliners for as long as there were piston fighters and
airliners.

As I said, I
think he has a point, but I have to consider that the engine manufacturers
and aircraft manufacturers might know at least as much about their products
as GAMI does.

That was true once, but is true no longer. For all practical
purposes, there hasn't been any progress made in piston aircraft
engines for decades. Neither Lycoming nor Continental have a design
engineering staff anymore. Most of the knowledge has been lost.

It's actually fairly common for knowledge to be lost that way. Doing
development is fun; documenting it isn't. When the people who did the
development move on, a lot is lost. Corporate-mandated processes
generally don't help much - they just cause the brightest people to
move on sooner.

Michael