Split cycle is back and could be here to stay

Split cycle engines are a bit different from our beloved, everyday, four-cylinder ICEs (in my case, beloved five-cylinders). Instead of having all the cylinders working in tandem, there’s two cylinders on either side, a bit like a V4 were there such a thing, but were the “suck-squeeze-bang-blow” four-step cycle is repeated by each pair of cylinders. The Scuderi engine was unveiled nearly two years ago, and was little more than a promise back then, with some haughty claims with nothing but Scuderi’s word to back it up.

But these crafty guys at Massachusetts-based Scuderi Group haven’t been sitting on their backsides all this time. They’ve been testing their engine in some American car, and have backed up their original claims, such as getting 135bhp from a single litre of displacement, high fuel mileage and drastically lower emissions.

This technology has been explored before without any meaningful success.

Other split cycle engines were hampered by low volumetric and thermal efficiencies that made them inferior to conventional engines. This new engine has pneumatic valves that open outward, pushing 100 percent of the compressed air out of the cylinder. This rectifies the problems of previous designs.

What does this mean for efficiency? Scuderi tested the engine in a 2004 Chevrolet Cavalier and claims the engine reduces NOx emissions by up to 80 percent and CO2 emissions by up to 50 percent. It also claims an increase in fuel efficiency of up to 36 percent over the Cavalier’s standard engine. (According to the feds, a 2004 Cavalier with a 2.2-liter four-banger and a slushbox was good for 21 mpg city, 31 highway.) You may be skeptical, and you may wonder how real this is. Scuderi says it had the Southwest Research Institute verify its findings.

The fuel economy is brilliant but what’s superb are the figures for the emissions. I imagine that as soon as they start mucking around with bigger engines, these could be an even more exciting figures!

Scuderi says the engine is built from conventional engine components and automakers could easily adopt it to suit their vehicles. It claims it could have the technology licensed and on the road within three years if all goes well.

How more fantastic could this news be? No big industrial shift, since current manufacturing processes and equipment can be used, no long wait… I can just imagine the future: driving along in a split-cycle, petrol-hybrid car, sipping tiny amounts of algae-derived fuel… aaah….