The Cult of Cars, Racing and Everything That Moves You.
We may earn a commission from links on this page

Scuderi Split-Cycle Engine Could Make 140 HP Per Liter

We may earn a commission from links on this page.

We've heard of the Scuderi Split-Cycle engine before, and we even spotted a plastic mock-up at SAE World Congress last year. This year the design is complete, and they project 140 HP per liter!


The Split-Cycle engine is a new type of compression cycle, so named for it's use of a pre-charge piston feeding an ignition piston which fires well after top dead center is reached. We spoke with company President Sal Scuderi about his engine.

According to Mr. Scuderi, the design is now complete on their first prototype engine, which is designed to run on virtually any liquid fuel with much higher efficiency than a traditional internal combustion engine. It does this with very high combustion pressures, generated from the built in compressor, driven by the same crankshaft as the combustion piston. The system relies on several vigorously designed elements like the pre-intake-valve mixing chamber, the lifting rocker arm which pulls the intake valve out of the compression chamber rather than pushing it in, the 2900 PSI fuel pump, and the compressed air transfer passages.


The novel post-top-dead-center ignition is made possible by incredibly high pressures and air cooled by the transfer passage with something similar to an in-block intercooler system, to adopt common lingo. The fuel is injected in to a carefully designed chamber ahead of the intake valve and the swirl effect creates a stratified charge injection, leaving a very controlled flame front and avoiding knock from high pressures.

What we see here is the bench display of the first finished prototype, and the engine currently resides at the company testing facilities in Texas, where it's about to undergo it's initial firing and tuning (the current configuration is even turbocharged to force even more air into the compression cylinder). Should the simulations and calculations prove accurate, engineers are expecting 140 HP per liter out this thing with significantly reduced weight and greatly improved efficiency compared to a traditional engine.

First Scuderi Engine Prototype Unveiled

Scuderi Split-Cycle Engine Technology Gives Automakers New Internal Combustion Process

DETROIT – April 20, 2009 – The Scuderi Group today unveiled a cutaway model of the first proof-of-concept prototype for its Scuderi Split-Cycle Engine, fulfilling a family dream and passing another milestone in developing a more fuel efficient, powerful and green technology for internal combustion engines.

The engine prototype was introduced to news media, automotive engineers, OEMs and the general public this morning at a news conference at the Society of Automotive Engineers (SAE) 2009 World Congress in Detroit. The engine cutaway is an exact duplicate of the proof-of-concept prototype undergoing testing and analysis by an independent laboratory in San Antonio, Texas.

(A podcast about the Scuderi Engine prototype and model is available at

The one-liter, naturally aspirated gasoline prototype is expected to produce up to 80 percent fewer toxins than a typical internal combustion engine. When fully developed with its turbocharged and Air-Hybrid components, the engine is expected to achieve significant gains in fuel efficiency – the most since the inception of the Otto cycle over 130 years ago. The original Scuderi Engine was designed and invented by Carmelo Scuderi (1925-2002).

The Scuderi Engine is a split-cycle design that divides the four strokes of a conventional combustion cycle over two paired cylinders: one intake/compression cylinder and one power/exhaust cylinder. By firing after top-dead center, it produces highly efficient, cleaner combustion with one cylinder and compressed air in the other. Unlike conventional engines that require two crankshaft revolutions to complete a single combustion cycle, the Scuderi Engine requires just one. Besides the improvements in efficiency and emissions, studies show that the Scuderi Engine is capable of producing more torque than conventional gasoline and diesel engines.

Scuderi split-cycle technology is significant because it gives automotive OEMs an immediate solution for complying with higher emissions and efficiency standards going into effect around the world - without having to make large investments to modify current production processes. The Scuderi Group expects further advancement of the technology once the greater engineering community begins working with the engine, making their own modifications that will most likely take the efficiency to even higher levels.

"This is a very proud moment for our company as well as the Scuderi family," said Sal Scuderi, president of the Scuderi Group. "After over seven years of hard work, this unveiling marks the realization of our father's dream and his vision of the full potential this technology holds. We strongly encourage automakers to take advantage of the opportunity that the Scuderi Engine presents to make more fuel-efficient engines."

With the assembly of the naturally aspirated Scuderi Engine now complete, the Scuderi Group and its independent laboratory continue to work on the next prototypes. Completion of the turbocharged Scuderi Engine and the Scuderi Air-Hybrid are expected in 2010.

About The Scuderi Group
Based in West Springfield, Mass., USA, with offices in Frankfurt, Germany, the Scuderi Group is a research and development company focused on proliferating its technology through R&D and licensing. Its revolutionary Scuderi Engine technology, when fully developed, is expected to be the most significant improvement in engine efficiency in over 130 years. The Scuderi Group's global patent portfolio contains more than 200 patents including 72 issued in more than 50 countries. For more information call 1-413-439-0343 or visit