Concept Engine
- http://conceptengine.tripod.com/
- Describes different engine design concepts, sorted by nation, as well as some support systems. Addresses efficiency and performance, insights, characteristics, with pictures and animations.
Kruse Limited Temperature Cycle
- http://www.kruse-ltc.com
- Describes an innovative thermodynamic engine cycle which limits peak combustion temperature in direct injection petrol, gasoline and diesel engines. Includes engine cycle overview and description, references, diagrams and patents.