Nickolas Otto got it right.

                                                                       Rudolph Diesel got it right

                                                                                  Felix Wankel got it right.

                                                                                 Robert Sterling got it right.

                                                                                 See who else might have gotten it right?

This website is devoted to amazing engines, unique mechanisms, and other attention getting machines that are not widely known. The site features my book(s) and some of the ammaging attempts at competing against the front runners. Innovation is paramount!

The book series will start with “Power Pioneers, The Art of the Engine, Pre 1956". Volume 1 will cover the years from the first combustion engines up to and including 1955.  The second volume series will cover the years 1956 to 1999 with the third volume series covering 2000 and on. There is also a distinct possibility that additional sub volumes, ie. Volume 1.2, could be added as I currently know of over 800 distinct and noteworthy engine patents from each of these time periods.

 The Art of the Engine’s mandate is to bring some of the lesser known alternative prime movers that have been hidden from the masses into plain view. This site is not about how well different arrangements work or even if they work at all, it’s about heat engine divergent ideas and their concepts. As both material and manufacturing processes improve, ideas that wouldn’t work previously become more viable with improved metallurgy and technologies or even just fresh thinking. 

This site and my book(s) use the convention that all heat engines will fit into one or more of five basic classes which I define as:

 Axial – have cylinders that are usually parallel to the output shaft. The most common type in this class are revolver types in which the cylinders are arranged around the output shaft like a revolver type of pistol. Cylinders are either opposed piston or opposed cylinder configurations and sometimes the block rotates about a fixed output shaft or the cylinder block is stationary and the output shaft rotates.

Inline – usually have the cylinders at an angle to the output shaft. This angle is usually 90 degrees for convention engines but there are variants that are 180 degrees. Included in this grouping are "V", "W", "U", "E", box, and similar configurations

Opposed – have either cylinders or pistons that are mated or mirrored against each other. The two major sub classes are either opposed piston in which the space between the pistons is the combustion chamber while opposed cylinder engines have separate combustion chambers. One of the major benefits of the opposed piston configuration is the reduce heat loss from non working surfaces.

Radial – have cylinders that radiate out from the center of rotation. These cylinders can also be of the opposed piston configuration at the expense of the crankshaft configuration complexities.

Rotary – have their cylinder block or its piston(s), which are sometimes commonly called a roton or a rotor, rotating concentrically or eccentrically  around the output shafts' center of rotation. 

ABOUT Ron Cairns


Ron Cairns REALLY likes engines. He grew up with engines, tinkering with lawnmowers and outboard motors. He especially likes all of the divergent thoughts on how to get more work from just expanding air. In the 70’s, he saw his first hyper expansion stroke barrel engine and his world was irreversibly changed. He started researching atypical engine configurations and soon realized most of the details were shrouded in secrets, misinformation, and misdirection. He started documenting many of these great designs and the facts surrounding them. In the 90’s he decided to write a book about them and hopes that you will share his enchantment with this easy to read and liberally illustrated book series. Through great parents, fantastic friends and dedicated professionals, the first volume has finally begun its journey.

He hopes these inspired engine designs help to inspire great thoughts for