Hi Paul,

I enjoyed your site very much.

I am fascinated very much by the wankel concept. I am looking to buy a cheap 1st airplane running almost out of engine hours with the plan to replace the engine by a Mistral.  But I talked a lot to RX7-8 owners all saying that you need a new engine every 100.000 km because of wear and tear. Why do you claim then this robustness and longevity in a wankel?

thx!

Rudy Berkvens
Wuustwezel
Belgium
Europe.

I can't explain it. Perhaps they are talking about the NSU RO80. Here in the states the Mazda's last 300,000 to 400,000 miles (not Km) if the cooling system and oil supply is taken care of. Thousands of 20 year old RX7s are still on the road. They dominated 24 hour endurance racing in the 1980's and won the 24 hour Le Mans outright in 1991. They are still winning here in the United States in the Rolex GT class despite severe penalties on max RPM and minimum car weight.  Many Mazda Wankels installed in aircraft running at 75% full power are lasting hundreds of hours and in some cases over 2000 hours. To my knowledge nobody has worn one out in an aircraft yet.

Yes they burn 5% more gas but that is more than made up for by the ability to burn car gas instead of more costly aviation fuel. When somebody builds a turbo compound version they will become the most efficient internal combustion engine of all time.

Paul Lamar