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Dan Gurney's
"Moment Cancelling" 4-Stroke Engine
Moment Cancelling Engine
Dan Gurney
Message From Dan Gurney

August 17, 2015

Why is the following on our website?

Because we have embarked on another substantial journey…

We are designing and building a brand new motorcycle engine. (It should be able to be used in other vehicles also, automobiles, aircraft, boats and so forth).

The first of five prototypes has not run yet. We plan to have it running on our test rig by the end of 2015.

I want potentially interested people or organizations to be aware of what we are attempting to demonstrate. So far, we only have simulation data which we are working with, but it all looks very good.

We have also managed to obtain a Patent on it, U.S. 9,103,277 B1. It is called the “Moment-Cancelling 4-stroke engine.” 110 cubic inch – 1800 cc.

Why this engine configuration?

Answer: Turbine Smoothness, simplicity and compactness.

Long before I obtained my license to drive a car, I realized how lucky I was to be born in America in 1931 when the automobile was really hitting its stride. Gasoline cost close to .10 cents a gallon and flat tires were becoming fewer and fewer. The dreams and activities of Henry Ford and others made automobiles affordable. I remember in about 1946, the first time a Ford cost over $1,000.

The automobile and the infrastructure which it helped create (roads and gas stations, etc.) meant that we were living in a country that was free and many of us could afford the equivalent of a magic carpet out of the Arabian Knights. You sit on it and it will take you anywhere you want to go. “The automobile.”

I’m not anti-electric automobiles. The fact is that there are global and U.S. oil and gas fields available which should last for many, many decades, I want to have a go at making the internal combustion engine even more competitive with (compared to) electric power for some of those decades.

Without special balancing systems, vibration and reciprocating engines go together. My experience is that things vibrate for a while, then fatigue and fall off or fall apart (like wires and lights and ignitions and exhaust systems).

I also have learned that there are many “rules of design” that cause compromises. Generally if you make a very high power for a certain size reciprocating engine, then you compromise the endurance and or the trouble free performance.

High RPM or high average piston speeds causes shorter life expectation for components.

Because of my own personal experience in life (I’m 84 right now) plus reading and a lot of talking with people I admire very much, it has dawned on me that I probably have had a whole bunch of experience. I had many troubles, many attempts that came up short and some successes that I’m proud of. Also, I have been inspired by many men and women who did outstanding things. Many I’ve met and some I’ve only read about. I started to write down a list of names and had posted a few on this website but the more I got into it the more I realized there was no way to cover all of them and do justice to the impact so many more people had on my thinking. One day I’ll make a definitive list.

Now back to the engine.

After modifying and trying to improve Ford V-8 flat heads, Ford 289 rocker arm engines, push rod 427 Fords, Chevy small blocks and big blocks of all sizes, Coventry Climax 4 bangers, Indy Ford 4-cammers, turbo Offy Indy engines, turbo Cosworth Indy engines, Triumph, BSA, Harley, Kawasaki, Suzuki, Yamaha, Honda, Montesa for motorcycles, S & S V-twins for motorcycles; also some Gurney Weslake cylinder heads for small block Fords and our own 3-valve per cylinder V-8 Ford conversion. Indy and NASCAR 355 cubic inch engines, (middle of the front row at Indy 500 in 1981) and quite a few others, 3-liter V-12 F1 engine plus experience with Ferrari, BRM, Porsche, Brabham, Lotus, etc. it finally dawned on me that AAR could design and build a whole engine from scratch if we had the desire.

My close collaborator Chuck Palmgren has had much experience with internal combustion engines during his career as an AMA Grand National Flat Track and Road Race motorcycle racer. He was his own mechanic and machinist on his competition bikes and he learned mostly the hard way just as I did. Together we should know a lot by now! Being competitors, we agreed that we should pool all of our knowledge gained through years of being immersed in the industry globally from many different angles. We sat down and drew up a list of attributes which we hoped to achieve with the design.

We agreed that the list should be arranged in the order of importance:

  1. Trouble free operation for long time endurance
  2. Reliability
  3. Robustness under harsh conditions
  4. Outstanding efficiency
  5. Outstanding emission reduction
  6. Outstanding mpg
  7. California 91 Octane fuel not a problem
  8. Low parts count
  9. Low manufacturing costs
  10. Simplicity
  11. User friendly power “flywheel”
  12. Very good power, naturally aspirated with 9.5 compression ratio
  13. Two buttons, two modes: (1) For best miles per gallon (2) another for best power
  14. Light weight

As you can see by the list of important targets influencing our design process, “power” is about 12th on the list.

Linked below are several stabs at a “sim” dyno run. We realize that detonation often limits power output. We shall do our best to avoid the limit.

We didn’t expect it to be as good as it is on the simulation. The simulation numbers are so good that we don’t want to “crow” about them before we actually see them on the dyno or in a vehicle. We want to wait until we are sure before we start bragging.

We hope the sim is right. It has always been very close on the other good engines that we have worked on.

Click here for simulation data.