Combination 2/4-stroke engine prototype tested

Posted Tue Mar 25 2008 3:33 PM by Nelson Ireson

Smaller, more powerful motors are the future of the auto industry. GM and Chrysler are focusing on smaller four- and six-cylinder motors for their Camaro and Challenger, while others are pushing the envelopes of forced-induction sub-2.0L powerplants. A new technology has appeared on the horizon, however, and it may steal all the glory if it proves cost-effective. Ricardo announced today it has completed initial testing of a dual two- and four-stroke engine which it claims can cut displacement in half without harming power output.

With an impressive specific output of 150Nm/L at 1,000rpm and 230Nm/L at 2,500rpm, Ricardo thinks the technology, called 2/4SIGHT, will allow a 2.1L V6 engine to keep pace with a naturally aspirated 3-4L V6 or V8 engine. Considering the 2.1L V6 would put out 460Nm torque at just 2,500rpm and have 300Nm torque available just off idle, the claim isn't just a pipe dream - if they can bring the technology to fruition.

Tests were run on a single bank of a 2.1L V6 motor, and computer simulations calibrated to reflect the load of a typical 1,800kg powered by a naturally aspirated 3.5L V6 driven through a five-speed automatic transmission. The tests showed a 2.0L 2/4SIGHT V6 could provide identical performance with a 27% fuel savings, reducing CO2 output from 260g/km to 190g/km.

The technology uses direct injection and forced induction combined with variable intake and exhaust valve timing, variable fuel injection timing and variable boost - all at an individual cylinder level, meaning each can be tuned for optimal performance instantaneously. Because the technology is so advanced, it will require a long development period before it can come to market, but Ricardo is currently seeking partners to bring the engine to life.

Gallery: Ricardo 2/4SIGHT Engine

Reader Comments

Tue Mar 25 2008 6:41 PM
Knight3058 says

Sounds promising.
Tue Mar 25 2008 6:51 PM
the gamper says

A 2.0 Liter 4 Cyl with Direct injection and turbo can already provide similar performance to a NA 3.5 V6. I believe with a fuel saving advantage as well, though maybe not 27%. I dont know about the emissions though. Anyway, it does sound promising and I am sure this is just the tip of the iceberg. Very intersting to see all the mpg automakers are able to squeeze out of a gallon of gasoline.
Tue Mar 25 2008 8:11 PM
Gus says

It does sound promising.
I've said it all along, though, the question of reliability comes up when you are squeezing THAT hard and using SO much technology.
I'm sure someday it will all be as reliable as ABS and airbags, which were once considered complex.
Tue Mar 25 2008 8:20 PM
shortroot says

@Knight3058: Sounds expensive (exorbitant)

Seriously though, it does look just a tad on the complicated side. I wouldn't like my chances of attemting to fix one that went wrong, and I am sure there is lots to go wrong.

It is good to be entering a time when people are attempting o push the boundaries of what is possible, but in a different direction. As I have said in the other thread, anything that helps save waste and maintains performance at the same time is alright in my book.
Tue Mar 25 2008 9:45 PM
Ivan says

I am sure if you would apply forced induction/injection for individual cylinder
on regular 4 stroke engine, it will be very efficient (yet complicated). That's where
engines are moving now anyway, not sure how 2-stroke helps here, more torque
at lower RPMs?
Thu Mar 27 2008 12:48 PM
aivi says

Patent of Ukraine â„– 41715A, 06.05.2001, author and patentee Andrey Ilchouk, at Ricardo plagiarism!!!
Thu Mar 27 2008 4:19 PM
peste says

This system is going to require a control system which will be an incredible pain in the ass to design and implement for durable operation
Fri Mar 28 2008 7:45 AM
aivi says

It is simple. But Ricardo does his difficult method. I know how to do it is better.

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