Scuderi Split Cycle Engine

The Scuderi Split Cycle Engine design is a rethink of the conventional four-stroke Otto cycle internal combustion engine conceived by Carmelo J. Scuderi (1925-2002). While as of this writing no working prototype of the engine exists, computer simulations carried out by the Scuderi Group and the Southwest Research Institute showed promising gains in efficiency and toxic emissions. It also has the innate capacity to power an air hybrid system.

n a conventional Otto-cycle engine, each cylinder performs four strokes per cycle: intake, compression, power, and exhaust. This means that two revolutions of the crankshaft are required for each power stroke. The Scuderi split-cycle engine divides these four strokes between two paired cylinders: one for intake/compression and another for power/exhaust. Compressed air is transfered from the compression cylinder to the power cylinder through a crossover passage. Fuel is then injected and fired to produce the power stroke. Because the engine produces one power stroke per crankshaft rotation, a Scuderi-cycle engine has the same total engine size (number of cylinders and displacement) as a comparable Otto-cycle engine.

The power cylinder fires just after the piston has begun its downward motion (after top dead center, or ATC). This is in contrast to engine design convention, which calls for combustion just before top dead center (BTC) in order to allow combustion pressure to build. The Scuderi-cycle engine can get away with firing ATC because its burn rate is faster, and so is able to build pressure more quickly. This property of firing ATC is a key feature of the design, as it enables the engine's higher efficiency and lower emissions.

Scuderi has been hard at work refining its split-cycle engine technology for the last few years, and the company believes that it's close to another milestone. Though still far from production, testing has recently validated an important aspect of the design involving the valvetrain, so vice president Stephen Scuderi believes that he is close to licensing the technology to other manufacturers.

The split-cycle engine is intended to be an improvement on the traditional Otto cycle and acts a bit like the Miller cycle. Instead of using a mechanical supercharger, though, the Scuderi design uses paired cylinders to compress air, which is then used to prevent reversion of the exhaust gases into the intake tract. It is also possible to store some of this compressed air to power the vehicle as part of a hybrid drivetrain. If this seems to make little sense (don't worry, you're not alone), click past the break for a computer rendering of the engine running.

This is the Scuderi Split Cycle engine. I noticed this in Cycle World magazine and thought I would check it out. It uses two cylinders, one for intake and compression and the other for power and exhaust. After compression, the charge is rapidly transferred to cylinder two where the turbulent mixture is burned more rapidly than usual meaning it’s cleaner than a standard engine, hence the name split cycle.

It’s a great idea, just like many of the other engines that pop up, but the news now is hybrid, hydrogen, biodiesel, electric and all of the really new technologies. These guys have a steep hill to climb, convincing investors to get behind an improvement in century old liquid fuel technology. Of course, diesel isn’t exactly new, but there’s been a leap in mileage and power and no new tooling is necessary for biodiesel. Anyway, it is interesting.

WEST SPRINGFIELD, Mass. - JAN. 23, 2008 - Reaching a significant milestone in its advancement of the world's most fuel efficient internal combustion engine, the Scuderi Group today announced the completion of the first independent laboratory study that predicts the Scuderi Split-Cycle Engine - under full-load conditions - will have higher power, torque and efficiency ratings than the current state-of-the-art turbocharged engines on the road today.

Completed, published and patented by an internationally renowned independent test laboratory, the long-awaited Full Load (FL) Study predicts the characteristic of a single stage turbocharged Scuderi Split-Cycle Engine under full load conditions (the maximum attainable torque at any speed). The FL Study is the first of three reports to be published by the laboratory prior to the assembly of the first prototype, which is scheduled for completion in 2008. A Part Load Study and an Air-Hybrid Study will be published in early and mid-2008 respectively.

The FL Study shows that the core Scuderi Split-Cycle Engine not only achieves higher efficiency than the best gasoline engines on the market, but it also shows that the Scuderi gasoline engine also has a higher torque than most of the conventional diesel engines in use today. Additionally, the predicted NOx emissions are 50% to 80% less than that of a conventional engine, which will mean an even greater advantage in diesel applications.

Since introducing preliminary designs of the Scuderi Air-Hybrid Engine to the automotive community two years ago, OEMs around the world have been eager to see these particular findings. The engine is expected to achieve significantly greater gas mileage than today's conventional and hybrid vehicles while emitting 80 percent less harmful emissions. With fuel prices soaring and unprecedented emissions standards looming across the globe, consumers and automakers alike are eager to see a viable alternative to the engines in use today.

"The results so far have exceeded our expectations. What we've known all along through our initial modeling is finally validated," said Sal Scuderi, president of the Scuderi Group. "This report shows that the Scuderi Split-Cycle Engine is poised to take the automotive industry into a greener, more fuel-efficient era."

Conceived by a team of fluid and thermodynamic experts, the Scuderi Split-Cycle and Air-Hybrid Engine technology is designed to deliver a significant increase in performance, efficiency and environmental impact over today's internal combustion engines. It accomplished these advances by focusing on the heart of the engine, challenging conventional approaches to engine design in place for over 120 years. Scuderi Engine Technology is adaptable to all fuel types, including diesel and gasoline automobiles, commercial vehicles and any other applications powered by internal combustion engines.