Ilmor Engineering touts new fuel efficient five-stroke engine design
Well-known British tuning and racing company Ilmor Engineering has announced an intriguing new test engine that's reportedly capable of returning diesel-like power and efficiency figures while running on standard gasoline and lowering emissions. Displacing just 700cc and yet putting out 130 horsepower and 122 lb-ft of torque, the turbocharged engine's secret weapon is in its fifth stroke.
Fifth stroke? Here's how it works: two of the engine's cylinders, running with a conventional four-stroke design, fire and expend their exhaust gases into a third low-pressure expansion cylinder. A fifth stroke then allows those gases to expand, boosting thermodynamic efficiency. Due to this clever design, Ilmor estimates a five-percent improvment in overall efficiency versus a conventional direct injected engine of similar displacement.
Future plans call for a second generation of the technology offering up 150 horsepower and weiging 20-percent less than current engines. Interestingly, Ilmor engineering manager Steve O'Connor says, "We're looking for a manufacturer to back the idea, and the interest centres on its use in a hybrid application, as they tend to need sudden bursts of energy, and that is what this engine does well."
[Source: Ilmore Engineering via Autocar]
Reader Comments (Page 1 of 1)
wincros 12:55PM (8/09/2009)
A five percent increase in efficiency over a conventional gasoline engine does not sound too exciting to me. You can do much, much better than that with just a properly set up turbocharger, a VW style turbocharger/supercharger combo, or a diesel engine. What we talking about with 5 percent is 31.5 mpg instead of 30 mpg. Whoop de doo.
I would be willing to bet that with the usual best case scenario hucksterism of people developing new technology that no one in the real world would be able to tell if it was more efficient. Kind of like cold fusion.
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Throwback 3:28PM (8/09/2009)
I doubt Ilmor would be involved with "hucksterism". They have a stellar reputation in racing circles. 122lb-ft of torque out of 700cc is amazing.
Jon 3:40PM (8/09/2009)
I'm more excited about it being 20% lighter. This would be great in a car like the Volt where the battery pack contributes significantly to the weight of the car - you want to save weight elsewhere as much as you can.
And if it was 20% smaller as well (which they don't specify), that'd be even better.
why not the LS2LS7? 1:01PM (8/09/2009)
An internal combustion equivalent to the old steam engine double expansion idea?
http://en.wikipedia.org/wiki/Compound_engine
'reportedly capable of returning diesel-like power' - Diesels are not powerful! Power is measured in HP, and Diesels are very low on HP for engine size. Even with complex turbochargers added they struggle to match the same power output of an advanced (especially turbocharged) gas engine. Diesels have a lot of torque, but not a lot of power for their engine sizes.
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Rain 3:55PM (8/09/2009)
"Diesels are not powerful"? Really?
Interesting that You bring up Steam engines and Diesels in the context of torque,since that is where these engines are productive at relatively low speeds.
High horsepower numbers allow high ground speeds,thats the distinction.
A broad flat torque is far more preferable than a narrow peak horsepower point,volumetric efficiency is the problem to the solution that engine designers have been hammering out for a hundred years in the quest for balance between power and driveability.
Either way,be it HP or torque N/M the RPM peak band is narrow,Turbo's and Superchargers expand on the desired bandwidth while increasing VE(Volumetric Efficiency)Superchargers fortify low end while Turbo's favor high RPMs.
What makes Electric motors promising is the fact that they make usable torque from one RPM to max RPM,moving the vehicle from stopped with a constant acceleration to the top speed.
The higher the Voltage,the more horsepower is possible while increasing Amperage means more torque is possible.
As Batteries improve in Energy density then so too will the range and
performance and mass production will bring down the price for the masses.
http://www.dieselpowermag.com/features/dodge/0905dp_1998_dodge_ram_2500/index.html
why not the LS2LS7? 6:13PM (8/09/2009)
Don't confuse broad and narrow torque with lack and presence of power.
Power is a specific measure, it is the ability to do work. It is measured in HP or kW. And Diesels are deficient on power. You say a Diesel is productive at low speeds? Fine, but if it makes half the HP, that means for work it needs to do, it does it half as fast as a higher HP motor. You see people saying "this heavy roof (or door) is closed with only two 14HP electric motors!" (see centre court at Wimbledon for the latest example). Yeah, but it takes 20 minutes to do so. This is a great example of torque (a measure of the ability to exert a force) compared to power, which is also includes the rate at which you can do so.
Volumetric efficiency is only useful for avoiding road taxes. An engine can have a very small displacement and be very large and heavy. Compare a pushrod gas motor to a turbo Diesel for example. The turbo Diesel is lower displacement but is far larger and heavier.
Your statement about superchargers and turbochargers is so broad as to be incorrect. A centrifugal supercharger only works properly at high revs, making your supercharger statement incorrect. And turbos can be tuned to be most powerful at either lower or higher revs, or, with variable geometry technology, good across a broad range. If you tune your turbo for low revs, you sacrifice peak power, but the full in of torque at low revs means the power output is far less peaky than an NA engine.
In an electric motor, voltage and current are proportional. As the voltage goes up, the current goes up linearly, and the power goes up with the square.
Electric motors do not produce a flat torque curve as you might imply. The torque is highest at zero (in the kind of electric motors we talk about on here), but it drops off as revs go up, partially because energy is wasted in centrifugal force.
I have no idea why people think batteries are somehow a nascent technology. There are a billion cell phones each year and each one has a battery. LIon batteries are well into the mature part of their lifecycle (they have been around 15 years after all!), we won't see huge advances in density, just incremental ones.
Rain 8:53PM (8/09/2009)
Perhaps when the roof over the centre courte at Wimbledon needs to shut faster,They'll put a Keith Black Mountain Engine up there.
Eight thousand horsepower at 5500 RPM should do the trick and such a lovely note!
DC Motors that are bandied about on ABG(as if it is the only kind)have an implied ratio expressed:
HP = T x N / C
where:
T = output torque in ft-lb
N = speed in rpm
C = the constant(not camper)5252
Speed is a by-product of power,but not everything needs to be fast.
In Our context:Haste makes waste.
Ian 3:57PM (8/09/2009)
I just want to make sure of something. The Ilmor Engineering Ltd is the jointly owned (Roger Penske and Mario Illien) company which helps Honda develop Indycar engines and works in Nascar development etc?
It should also be noted that RP presently imports the Smart car into the USA and has bought out Saturn and is looking for new cars to replace current Saturns.Perhaps his idea is to use such a power unit in new Saturns?
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NeilBlanchard 2:35PM (8/09/2009)
Hi,
If they mean increasing the thermal efficiency from 20% to 25%, then that *is* a BIG deal!
Sincerely, Neil
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Nick 2:52PM (8/09/2009)
What happened to the idea where water is injected in the cylinder after the combustion cycle?
A 5% increase really isn't much..............and besides, isn't this increasing backpressure in the exhaust?
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sitruc1ofa 4:06PM (8/09/2009)
This engine seems to do the same thing as a turbo compounding engine. Using a turbine or an extra cylinder both act as a means to extract work from the exhaust and return it to the driveline.
I'm not sure what they mean by 5% efficiency gain. does that mean that they go from say 30% to 35% (gain of 5% total) or 30% to 31.5% (5% increase over baseline). depending on how you look at it, 5% could be a huge increase in efficiency
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JeremiahBWhite 8:25PM (8/09/2009)
Interesting.... I think I like this one better: http://www.autoblog.com/2006/11/15/fiat-500-to-come-with-two-cylinder-turbo-engine/
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