SAE 2009: Scuderi unveils cut-away of split cycle engine
by Sam Abuelsamid on Apr 20th 2009 at 4:29PM 
The Scuderi group unveiled a cutaway version of its first prototype of a new split cycle engine at the SAE World Congress this week. We first heard about this engine three years ago and got more details at the 2007 SAE WC, but this is the first time we have seen something physical rather than just CG animations. The first actual running prototype used to prove out the combustion process is being assembled right now and expected to start running by mid-May. It will be a normally aspirated variant with a displacement of 1.0-liter.
The engine uses pairs of pistons operating in parallel to split the typical 4-stroke cycle into pairs of two strokes. The first piston handles the intake and compression strokes with only air coming in. As a result, the air is compressed at a ratio of 100:1 before a crossover valve is opened allowing the compressed air to pass over to the power side. What happens next? Find out after the jump.
Gallery: Scuderi split cycle engine
A pair of poppet valves manage the flow of compressed air to flow from the compression to the power cylinder. However, because of the high pressures being generated, approximately 50 BAR, Scuderi set the crossover valves to be outward opening (that is, they open away from the cylinder rather than into it). As the compressed air passes through the crossover, the shape of the passage and high pressure combine to induce more swirl. A Bosch-supplied injector of the same type used for direct injection systems sprays fuel into the cross over passage and the high pressure air causes it to mix more thoroughly than a conventional engine.
Scuderi believes that they can make this design work with the fuel being ignited after the power piston passes top dead center. Firing the spark plug after TDC prevents any re-compression of the expanding gases, raising the thermal efficiency compared to earlier split cycle engine designs. The cylinder pressure rises to about 65 BAR during ignition but drops as the piston moves down the cylinder. The result is that the combustion temperature actually drops at the same time, eliminating about 80 percent of NOx production.
Scuderi claims the split cycle process will work with spark ignition as well as compression ignition diesel engines. The first prototype is normally aspirated and Scuderi expects it to get about same fuel efficiency as a similarly powerful conventional Otto cycle engine. The big advantage will be in emissions with dramatic reductions in NOx and HC.
Future variants will include turbocharged and air hybrid designs that will allow increased efficiency in addition to the lower emissions. The turbo version could produce up to 135 hp/liter allowing for a much smaller engine without compromising power output. Scuderi is also developing an air hybrid variant that adds a high pressure air accumulator to improve the efficiency of the engine to a level the company claims will be comparable to current gas-electric hybrids at much lower cost.
Speaking of cost, Scuderi claims that in spite of the new architecture, the split cycle engine will cost about the same as a conventional engine of similar output. A diesel version could conceivably significantly less expensive because the complex after-treatment systems could be scaled back or eliminated while still meeting emissions requirements. Scuderi claims to be talking to a number of automakers about licensing the technology and hopes to have a deal within a year to 18 months. Hopefully, a production engine based on this design will be on the road within 3-5 years.
Reader Comments (Page 1 of 1)
Swede 4:40PM (4/20/2009)
Zzzzzzzzzzzzzzzzzzz
Wake me up when one makes it into a production vehicle
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contact 4:41PM (4/20/2009)
Wow, very interesting. I'm always excited to see new technology and new ways of thinking. This type of innovation is what separates us from the monkeys.
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Tohe 2:01AM (4/21/2009)
Yeah the monkeys are leap and bounds ahead of us in terms to their carbon footprint. Damn monkeys.
contact 6:35PM (4/21/2009)
I can't tell if you're trying to be funny or argumentative. This whole "carbon footprint" thing is a stupid measuring stick anyway. There HAS to be some sort of impact on the world for everything we do. For every action there is an equal and opposite reaction.
I'd like to a see monkey perfect space travel.
DasBoese 9:05AM (4/22/2009)
This isn't "new technology".
It's a two-stroke engine with a piston scavenging pump/supercharger, these things have been around since the 1920s.
They just added some modern technology like fuel injection and gave it a fancy new name.
Nateb123 2:39AM (4/23/2009)
@DasBoese
Agreed. It's nothing particularly fantastic or new or beneficial.
Note they don't even say that anyone important has expressed interest, just that they're talking to them. Basically someone at Scuderi gets paid to play the automotive door-to-door snake oil salesman.
I'm betting it can't rev, it overheats and seizes like a mofo. (It's got about twice the moving parts of a similar sized Otto-cycle engine so you know it will be fighting a TON of friction). All that and it probably won't be able to maintain a proper seal between chambers making it terribly inefficient.
UH2L 6:31PM (4/20/2009)
I know the company wants to get the best deal for licensing the product, but this is the kind of technology that somehow needs to get fast-tracked for the benefit of society and the environment. Wouldn't it be great if the U.S. government, military, or NASA bought exclusive rights and sub-licensed it to only our US-based companies? Or they could license it to any international company and make money to fund other green projects. I don't know the legality of such an arrangement, but some outside-of-the box thinking could work well in this case.
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gorr 8:00PM (4/20/2009)
Why there is't a real prototype running ? These images are computer made. It's the 200th time i see a theoric ' new' internal combustion engine.
It's full of flaws in the theoric domain like the pr campaing of gm with their green volt that move forward with toxic gasoline and coal electricity. It's one example out of a tousand exemples.
This engine may be good for one type of application or may be plague by some unpredicted problems like; slow rpm; over-heating; pre-ignition; difficulty of lubrication; parts stress; timing problems.
It can maybe very good but i'll prefer to see a working prototype running for 1000 continuous hours.
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Randolph Toom 7:10AM (4/21/2009)
Congratulations to the Scuderi Team for making this progress. I hope you will succeed in getting your engine to the market and I am looking forward to see you again at Engine Expo in Stuttgart.
Best Regards,
Randolph Toom
Managing drector of heat2power
www.heat2power.net
mapoftazifosho 9:28AM (4/21/2009)
So what would you prefer? Nuclear power across the US and we just toss the waste in Yucca mountain and hope for the best?
Every power source has it's downfalls.
Solar won't work for much of the country and wind power creates horrible noise pollution. I'm not against either of these technologies, but the Volt is a step in the right direction. The EV1 was a big step too, but that was powered by evil coal...
mike 3 9:22AM (4/21/2009)
sounds to me like they want to keep us hooked on oil! yes this may make vehicles lower cost for the next 10 years or so, but when demand exceeds supply again we are right back to where we started! personally I am a fan of the Bruce Crower’s Six-Stroke Engine, put that in a Prius or Volt. Anything we do from here on out should be paving the way to eliminate any nations dependency on foreign energy supply.
also I agree with the comments by "gorr"
"This engine may be good for one type of application or may be plague by some unpredicted problems like; slow rpm; over-heating; pre-ignition; difficulty of lubrication; parts stress; timing problems."
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mapoftazifosho 9:34AM (4/21/2009)
No, I think they simply want the most realistic way to reduce our use on oil...the idea that we are just going to drop oil without interim technologies to reduce our use is a joke and pipe dream that uneducated hippies seem to believe.
The consumer is used to the I.C.E....not to mention the normalcy of pumping fuel and the safety net of having refueling stations everywhere. Cutting our consumption of oil with cheap technology such as this and the VOLT is a good step. You can't expect a crack addict to just stop using altogether...
PFB 3:07PM (4/28/2009)
To Nateb123,
If you read the Wall Street journal April 21st 2009 it confirmed with
Daimler and Fiat exexcutives they have interest in the Scuderi Engine. Also note
Honda's comment which was we do not comment "on future projects" On future projects sounds like they are very interested and Honda has signed an nda along with at least 10 other major OEM'S. Things are looking good for the Scuderi Engine.
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Peter Hill 5:17PM (5/09/2009)
It can't ever achieve the claimed efficiency.
They make claims to having 100:1 compression ratio for compression cylinder but this just proves they are stupid. The compression ratio is (swept volume + chamber volume) / chamber volume. For the compression cylinder the chamber is the transfer port or receiver vessel between the 2 cylinders. They don't actually have any more than 5:1 CR with the port and once they put a receiver vessel on it will less than 1:1.
Then they open the inlet to the power chamber and reduce it still more.
Only way to fix this is to make the compressor 10x the size and then they will find they have 4% or maybe 5% overall efficiency - about 1/10 of current best such as Rolls-Royce Bergen K series.
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CVR7 10:24PM (10/23/2009)
You're very obviously mistaking geometric compression ratio for effective compression ratio. This is such a newbie mistake that I question your motive, maturity, and intelligence.
The effective compression ratio can be controlled by varying the timing of the valves. If you don't even understand this much then there's no hope for you.
You have it backwards. Your analysis only proves you are at least one of stupid, ignorant, and malicious.
Peter Hill 5:57AM (10/24/2009)
Newbie? I have CEI Pt2 passes in Mech Dynamics, Thermo, Fluids, Maths and Stress. This a MSc by current standards.
For your information effective compression ratio is always less than geometric.
CVR7 9:16PM (10/24/2009)
Wow, thanks for the insightful comment. I suppose I couldn't have figured out that effective compression ratio is always less than geometric given that my graduate degree isn't in fluid dynamics. Unbelievable.
Scuderi is obviously measuring the geometric compression ratio without including the chamber. You probably knew this.
Your calculation of the effective compression ratio is absolutely dead wrong. The compressor is pumping into a chamber full of compressed air, not ambient. A mass of air is pumped from the compressor to the chamber and an equal mass leaves the chamber to fuel the expander. This is a simple concept that you do not need a graduate degree to understand.
Scuderi is claiming 40 to 50 bar pressure in the chamber for a naturally aspirated engine (Source: Scuderi spokesperson at SAE). If my memory serves me correctly this means a 15:1 to 20:1 effective compression ratio.
Your knee-jerk reaction of accusing Scuderi of being "stupid" is totally baseless and absurd. Do some homework next time.
Peter Hill 7:17AM (10/25/2009)
How does the transfer chamber get full of air?
Starting from cold and empty with 1 bar in the transfer/reservoir how many revs does it take to get the thing started? What size starter motor and battery will be needed to crank it up? Bear in mind a normal engine is started at part throttle, cranking at 300rpm and fires up in about 5 revs, this thing will have to be cranked at wide open throttle. Even Diesels that run WOT don't pump to 30bar when cranking.
It's got a transfer port/reservoir that needs to pump up/down, how long does it take to respond to throttle?
Due to throttle response, it's not fit for use as a normal automotive power source. Maybe as a stationary generator engine or in series hybrid - which would allow for the number of revs and power demand to pump up to working pressure.
Whats the volumetric efficiency of the compressor at 30bar delivery pressure? All the air in dead space just re-expands and never gets transferred to the power cylinder.
Bear in mind that the cycle they had analyzed and are still touting [1] with a claimed 40%+ efficiency was the one in their grandfather's patent that had "instant transfer" of ALL the induced air with NO dead space volumes (the first and original BIG JOKE). They can't achieve that instant transfer and transfer process involves high loss flow though 2 valves. The dead space of compressor clearance, transfer ports and residual volume of exhaust gas in power chamber compression space also eat into the efficiency. It's easy to claim a high efficiency when an impossible to achieve cycle has been analyzed.
Take a look at some more of the early patents, they feature such mechanical wonders as BENT connecting rods!! Wonder who had to tell them that bent con rods were a big joke too?
[1] Even though they MUST know the truth by now - or are they really that stupid they can't see that the original analysis is worthless junk. If they know then they are running a SCAM, if they don't they are utter idiots. The frantic attempts to extend the transfer phase duration by means of such devices as the cam guided big end appears to indicate both!
CVR7 1:04PM (10/25/2009)
You have a clear grudge and nonobjective viewpoint. You could have admitted that your original analysis was dead wrong, knee-jerk, and nonobjective. Anyone with any degree of integrity would then have taken the time to actually figure out what they're talking about.
Instead you resort to yet another knee-jerk nonobjective analysis - making up further lies and citing any possible problem you can think of, as if such problems cannot be solved and are not already solved. For this reason I'm not going waste any further time responding beyond this response.
There are no bent connecting rods in the product, and patent diagrams obviously (to everyone but you) do not need to be perfect. I cannot find that instant, zero-loss transfer was originally claimed or claimed now (you're probably reading some text through your tainted viewpoint). These just mere examples of blatant and obvious flaws in your crackpot, knee-jerk, do-anything-to-discredit Scuderi reasoning. Others (e.g., dead space - we already went over this) are so silly that they do not even merit explanation. Use your "MSc" expertise (which I do not believe) to figure them out.
There is no evidence at all of a scam and your comments probably constitute libel. The only "stupid" one here is you. You should really get some help.
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