Maybe lots of airflow people made the same discovery the late Jim Feuling did: In many, if not most, four-stroke engine designs, the exhaust valves and ports are oversized and under-streamlined.

I know at least one who made the same discovery, my friend, the late Kenny Augustine. When I asked him about the Honda 450cc twin, he replied, “You got the head on your flow bench?”


“So you’ve heard the roar the exhaust makes?”


“That roar is the flow, unable to decide whether to stick to the roof or the floor of the port. So it oscillates back and forth. Now push a pencil in along the floor of the port. The roar will go quiet. Now flow is just sticking to the roof because the pencil is in the way.

“That port is too big. Just start adding clay to the floor of the port and you’ll see the flow go right up. When you get to 15 percent more than stock, stop; that’s all you’ll get. Now start filling the back of the exhaust valve, giving it more of a tulip shape. That’ll give you another 15 percent, or 30 percent more total flow.”

Feuling must have had a parallel experience, but he didn’t stop there. He must have had some specific industry problems in mind because the idea that an engine’s stock exhaust valve and port were 30 percent oversized once they’d been properly streamlined led to a question: If I could make stock exhaust valves and ports smaller and yet make them flow just as much as before, what could I do with that?

Lots of smart, hard-working flow-bench artists have come up with ideas that were promptly adopted by engine manufacturers on new models. But very few have ever been paid for anything other than their labor.

He could move the existing exhaust valve away from the intake valve (in a two-valve-per-cylinder Detroit automobile engine), making room for the intake valve to be enlarged. He could substantially reduce the exhaust heat flowing into the head because a smaller port and valve would have less surface area through which the head could be heated.

The next question was, “Who will pay me what this is worth?”

That is the tough one. Lots of smart, hard-working flow-bench artists have come up with ideas that were promptly adopted by engine manufacturers on new models. But very few have ever been paid for anything other than their labor. One of the first rules of earning real money is, “Never sell your labor.” How does the shape of a port become protected intellectual property and then how do you sell it? I know two men who spent 10 years of their lives promoting a unique automotive technology. When their years in hotels and airliners finally landed them a solid buyer, negotiations broke down when they discovered that the buyer’s many delays were just cover for a legal team working to break their patents.

If motorcyclists have heard of Jim Feuling, it is as the man who created a W3 engine employing Harley-Davidson cylinders. Feuling put as much work into protection of intellectual property as he did into creating it.

In the 1930s, engineer Roland Chilton had a similar outlook, refusing to sign a standard assignment-of-patent-rights agreement: He was a consultant. His patented design for a pendulous crankshaft damper worked so well that it was widely adopted on radial piston aircraft engines, and for every example manufactured he was paid a royalty. He became wealthy. So did Jim Feuling. One of his indulgences was his interesting collection of tanks and armored vehicles. If you ask around, you will find that Feuling had both critics and enemies.

Feuling described to me being in dreary Detroit conference rooms, smelling of coffee makers boiled dry. At the head of the table were the managers who had contracted with him to solve a problem. They were flanked by a small group of other men—engineers.

The Big Cheese led. “Why should we pay serious money for your concept when our own engineers tell us it can’t work?” He motioned to the other group.

An engineer spoke. “We have evaluated your proposal and we advise against it because it does not lie along the line of best design practice.”

Feuling replied, “You wouldn’t have asked me here in the first place if best design practice could solve your problem. Who are you going to believe? Best design practice? Or the test results from your own labs that show that my proposal—built and tested by your own people—gets the job done?”

Feuling knew that the deciding point in such discussions comes when it costs less to buy the innovation and fix a costly problem today than to delay by fighting a patent through the courts. The key for the patent holder, Feuling, was to have the solution plus a strong legal position prepared by respected persons.

Years later, I was replacing the exhaust manifolds on my wife’s station wagon. Damn! Those ports are really small: Feuling was here.