This internal combustion engine did not need oil, at least on paper – Jalopnik

Ford once outlined a road where the pistons of an engine never saw oil and engines. In a patent application described and granted in Europe at the end of the 1980s, the company described an “untrooled oil -free” internal combustion engine. What it did was replace the liquid film that conventional oil -cooled cylinder walls in a piston motor with a gas lines cushion. The idea was simple in theory, but radical to implement. If you can keep a razor blade between the piston and the cylinder wall and use the movement of the piston to drag air through carefully shaped grooves, you can build a self -pumping “gas squeeze film” that separates the moving parts.

The patent even specifies the use of ceramic components (including the cylinder head, cylinder walls, pistons and valves) with a low thermal conductivity, so that the engine retains and works efficiently at high temperatures. In short, less parasitic losses, fewer liquids and a cleaner combustion, at least on paper. The archiving describes ringless pistons, cleansing at micron level around the ingredient of a centimeter and step -like characteristics that form air flow in a pressure put under pressure while the piston travels. If the parts are perfectly straight, they will retain that small opening, and the gas film will usually take off the working oil.

The catch is, as always, in the details. Modern engines use oil for more than lubrication. It also cools and cleans the engine. Motor oil additives such as Seafoam and Lucas help in some cases. All that replacing with air and ceramics would demand a new way to build engines from within.

The patent application requires high -roughness, low conductivity ceramics such as sintered silicon nitride, silicon carbide and partially stabilized zirconia for pistons and feedings. That recipe limits thermal expansion and keeps heat in the combustion chamber. Then comes the construction. Instead of the piston rings, the piston itself and the cylinder boring are hanging in front of having a radial tapered. While the piston travels, fishing choice drag air into the opening. The tapered shape compresses that local air, creating a uniform pressure field that supports the piston on an air cushion thousand centimeters thick.

The application also anticipates pressure differences. During the exhaust and intake strokes, the gas film is weak because the pressure food is low, so the design is ultra-smooth finishes, controlled clearance and hard, wear-resistant surfaces to survive short metal-metal contact periods, say during cold start. As soon as the engine reaches the business speed, the gas cushion bears the load and the blow -or drops to very low levels (less than 2% of the current above 1500 rpm).

Without piston rings and no oil control tasks, friction falls. With an uncooled block and head, the engine retains heat and puts it theoretically more in useful work. The net promise is less losses and simpler sanitary. On paper you end up with a heter, slimmer, cleaner machine that bypasses the messy use of oil and added the production complexity.

The reality a bit hard. Keeping a nice gap between a hot piston and hot cylinder is a nightmare with metrology. The small opening distance between the piston and cylinder wall is the key to keep the piston aligned, to reduce friction and prevent bladder, but it constantly shifts with heat, engine taxes and other forces that engineers must manage carefully. Ceramics is strong, corrosion-resistant and heat tolerant, but they are expensive for machine and reaching high-micron tolerances can be expensive. Ceramics can also be ruthless under impact tax and harmful to the environment during extraction and waste handling.

The gas film is engine-speed-dependent, so start-up and stationary are its danger zones when metal-to-metal contact is likely. The effect is comparable to changing motorbike pressure due to viscosity changes on colder and hot days. Dirt or carbon In that microscopic opening can score surfaces that are not easy to repair. And the rest of a modern engine still wants oil for cooling components, driving variable valve equipment, operating hydraulic tensioners and the removal of debris. Modern oils become thinner, but are still needed for the functioning of the engine.

There is also the heat problem. A non -cooled, low -the -abetermination engine runs very hot, up to 1600 degrees. The challenge lies in finding out how you can make the lubrication of the gas phase work reliably work while dealing with thermal expansion, changing tolerances and the absence of traditional oil. The production -challenging is on top: the required tolerances and finishes are feasible, but they are cheap to scale to scale is a different story.

That is why this concept remains a fascinating branch on the motor family tree instead of the trunk. The patent expired years ago and the fully Oillesess Auto Engine has never arrived. But the research still drives how engineers chase lower friction and higher efficiency.