All, Some food for thought.  Powersport has started replying to e-mail on another list, and was asked about the Renesis engine.  This is what Tim had to say.  I had thought that the Renesis would have been a great aircraft engine, but would have to lean towards more educated opinion.  The questions to powersport and their replies are copied in full below.

I would appreciate any feedback on what is said.

Thanks,  Greg Fuess

Thanks for the info. Some questions for you:

1. What is the status of Powersport? Is it currently shipping FWF
packages for RVs? Which model RVs?

Currently we have completely developed FWF packages for RV 6-7-8-9 (9 at your own
"not recommended by Vans" discretion.)

2. Is the Renesis engine interchangeable with the old 13B? Obviously
different exhaust, but are the engine mounts, etc. the same?

Simply put, the Renesis is not suited for installation in aircraft. There are many
reasons for this.

3. Is the Renesis engine better than the old 13B for aviation use? I
understand it has better economy and sealing due to the new port
arrangement. Is there anything else we should consider?

No, the Renesis is far worse for aviation use. It does not have better economy,
especially at the RPM range used in an aircraft. It is lower HP! It still needs a suitable
aircraft ECU added. It develops its HP at a higher RPM with will reduce its life cycle.
The changes made were for emissions and low end torque, which are not important
factors in aircraft. Mazda still uses P-Port system for their top racing application.

4. Is Powersport planning on switching to a Renesis-based FWF?

No, see above.

I am not saying the Renesis is not a good engine, it is a great engine... for a car.
The HP ratings are way overstated. Those who have run them on dynos have reported
outputs around 180HP.

Thanks,
Tim