I know that his is an old topic but I felt some things were missing.

I have had vast experience on both the R3350 a lovely engine but with its faults, and also the Centaurus and Hercules engines. They are complicated , for example there are 49 gears in the front gear housing to drive the sleeve mechanism in the Hercules..

A good read is By Jupiter and live story of Sir Roy Fedden and the delevopment of the first sleeve valve engines and the trials and tribulations of development.

as the JUpiter, Pegasus, Hercules and Centaurus engines evolved wear was a problem, this was taken up with Shell Aero division who formulated a hi spec Mineral oil for the engines. Aero shell 100 U. This was a winner and wear reduced and a longer engine life.
Any Engine if mishandled will fail somewhat, take a Bog Standard R3350 and exceed 3000RPM by a little and standard Articulating rods will get a .010″ bow. Centaurus engines will display faults I am sure.

Now back to the exchanging of the Centaurus with R3350 turbo compound engines , in my mind, is the shortage of the Bristol engine and a POSSIBLE nil availability of Aeroshell 100 U which is essential for smooth running of the sleeve valve engines.

SOme years ago I visited Oshkosh a had casual talks with some engineers/Mechanics working on ex RAN Sea Furies and asked them why the exchange. all answered , more engines and availability of spare parts. Nothing else came into the equation. I may have missed some things but have written to the best of my recollections.