Low Cost Gas Engine Innovation Doubles Fuel Economy
Revetec, a little known company from the Gold Coast region of Australia, may be on to something huge: they’ve created an engine that is 50% smaller, 50% lighter, has 50% lower emissions and is cheaper to manufacture than a conventional internal combustion engine of the same horsepower. Oh yeah, did I mention that it doubles the fuel economy too.
What that means is a car like the 2007 Toyota Yaris, which is rated at 40 mpg on the highway, would get 80 mpg with a Revetec engine.
This isn’t some hoax… They have a prototype which has been attached to an actual vehicle and independently tested to substantiate their claims.
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In personal communication with Mr. Brad Howell-Smith, the Chairman, Inventor and CAD Designer for Revetec, he says “road tests have estimated that [the engine] uses around 50% less fuel than a conventional engine” and if it were converted to run on diesel, that performance gain could be much higher.
Also, because the engine delivers higher torque, and can perform and operate well at much lower rpm’s than a conventional one, the noise levels are lower.
To illustrate how serious he is, Mr. Howell-Smith said that since 2001 his company has been in touch with the US Military Head of R&D for the Southern Hemisphere on a “regular basis” for the purpose of developing one of their engines for light aircraft.
The current prototype engine, the X4v2, is what Revetec calls a “controlled combustion engine.” The meat of the engine comprises two counter rotating multilobate cams, which are acted upon by two pairs of diametrically opposed pistons which are rigidly interlinked by connecting rods.
If that sounds like complete gibberish to you, you’re not alone. Which is why I included an animation of the process to the left. A more simplified animation of the general motion of an engine of this sort is also included below.
Mr. Howell-Smith said that “if [the engine] uses 50% less fuel given that it has the same top end as a conventional engine, emissions would be reduced by 50% if the bottom end was utilized.”
What does all that stuff about “bottom end” and “top end” mean? The X4v2 has a huge amount of torque over a much larger range of rpm’s than a conventional internal combustion engine.
If a person were to drive a vehicle fitted with this engine in a non-aggressive fashion and keep the rpm’s at the “bottom end” (meaning no “jack-rabbit” starts) they could expect to see a 50% reduction in emissions.
Alternatively, according to Mr. Howell-Smith, a person could see a 30% reduction in fuel use and a 30% reduction in emissions if they used the full acceleration power of the X4v2 all the time. This would provide a 20% increase in acceleration capabilities.
We could debate about whether or not the internal combustion engine has a place in the future of transportation or whether it’s going to be all-electric or fuel cell or whatever… but in the meantime, Revetec has a product that could revolutionize the the transportation industry now, and provide a much needed large reduction in fuel consumption and emissions.
Just imagine a bunch of 80 mpg Toyota Yarises (Yarisi??) running around all over the place. A little scary, I know, but… an 80 mpg conventional automobile? I must be dreaming, wake me up before I get too excited.
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Image Credits: Revetec
How long does the engine last, as many miles or more than a conventional engine?
Philip, July 8th comment - page 7, has hit the nail on the head!! The engine has “spoken for itself” now that Orbital has made its report on 38-to-39% efficiencies without any high-tech top-end refinements to Brad’s engine.
It’s time to consider the business side of getting the REVETEC Engine to its next level:
Funding is required. So, who among us can help Brad get this modern marvel into a new high-milage factory-new car so that a real comparison to the best mass-marketed 2008&09 car can be used as a current market comparitor?
And, who among us can contribute funds and exertise for the top-end refinements that are required in order to complete a “whole package” for Brad to apply his talents on?
After all, even though the bottom end is spectacular, the market place (OEM car manufacurers) are undoubtedly wanting to wait so they can commit to a complete engine system which has been tested and demonstrated to out perform the new competion.
It’s time for us to “network” this challenge to any and all who are enthusiastic about REVETEC and might be or might know who could be substancially helpful to this promising innovation’s advancement to market.
“Enough said. Now let’s get with it.” Network this challenge and if you can actually help Brad “move this along” (as opposed to loading him with technical challenges, then email him.
Interesting design, would love to see this in my Excursion, which would mean I get a whopping 20-24mpg, I love it and won’t be getting rid of it for a while.
I agree with John; lets get it moving.
For those of us with funds.. invest! invest!
But there is no need to drop the discussion; technical challenges whatever, that doesnt stop anything and can bring useful ideas to the forefront. Its not “negative” thinking. Early problems can kill a project dead, a problem spotted early can save everything.
An example of a new idea, Devon wanting to see it in his Excursion.. can it ? - or the basic short engine - be retrofitted to an existing car? It seems to be compact enough and uses the same top end — the advantages would seem to make it worthwhile!
I mean private owners doing this via a garage — like aftermarket turbo chargers and propane conversions. It would be a start and would get market confidence
That idea would also provide an ‘in’ if the main manufacturers are slow on the take up.
The main manufacturers resistance to change and risk — or worse open hostility — I see as a real potential problem. I believe there are precedents in history; if nothing else the possibility would make investors wary. It also needs some goverment support, the goverments blessing as it were, since it would be sad if the development failed due to some regulatory problem (real or percieved)
And then there is racing — this isnt a race engine, but maybe it could be? Racing “improved the breed” in older times and a 24-hour le Mans win would be great publicity — and hey.. less pit stops !!! (now theres a thought)
[...] Obama will double fuel economy standards within 18 years. His plan will provide retooling tax credits and loan guarantees for domestic auto plants and parts manufacturers, so that they can build new fuel-efficient cars rather than overseas companies. Obama will also invest in advanced vehicle technology such as advanced lightweight materials and new engines. [...]
please tell me more about differential gearing used here to rotate the output shaft in the same direction.
The engine is very interesting. There are about 80 patented rotary engines of one sort or another that I have examined and this one has many similarities to a couple of them. The Revetec still hasn’t overcome the inherent problem of excessive heat loss, read energy loss of pretty much all combustion engines.
Like Mr. Howell-Smith, I have patented and built a prototype combustion engine which is highly asymmetric (the intake volume is far less than the expansion volume) which means that the engine is thermodynamically very efficient. The concept of asymmetry is not new but this engine (the DPATS for Double Piston Asymmetric Two Stroke) is simple and does not have all the accompanying cam shafts etc which complicates things so much. The aim of this engine is to run on CWS (coal water slurry) fuels as done in Detroit a year or two ago and drive rail, transport and electricity generators. Most people don’t realize that it is possible to combust coal without producing CO2 as shown by chemical thermodynamics. We just have to get the reaction fine tuned for combustion engines.
Congratulations to Mr. Howell-Smith for getting this far with his engine. I have found with my invention that the world is chockers with skeptics and nay sayers. Wish me luck!
Hi guys and gals,
Thank you for the comments on the article on our engine.
First I might mention Orbital. Orbital has a world class testing facility that test and optimise engines for clients such as: GM, Ford, Toyota, Mazda, Renault etc. They have very accurate test equipment and are highly respected in the engine testing field.
During testing, they checked and recalibrated their equipment 3 times during the testing, as they didn’t believe at first the fuel efficiency the X4v2 engine was delivering. In fact they were very careful in the testing, because if they didn’t have enough data and had the correct procedures performed to back up our results, they would come under attack from other companies who had tested at their facility.
The efficiency figures are correct, and are consistent with our in-house testing figures.
Moving on to crankshaft efficiency, peak combustion pressure occurs around 15deg ATDC. At this point the con-rod has a small amount of torque lever applied to the crankshaft. Maximum leverage from the con-rod to crankshaft occurs around 70-80deg (depending on the length of the con-rod) at which point the combustion pressure is around a half of the peak pressure. When I first designed this engine concept, I calculated cylinder pressure VS torque lever on our engine and a conventional engine. I calculated it every 1/3 of a degree of rotation. The calculation clearly shows a 35% loss in transfer (please calculate it for yourselves). We have reduced this to 15% losses.
I know some people won’t understand this fully, but if you provide higher leverage and maintain that lever longer, the pressure from combustion is converted to crank torque more efficiently.
Now let’s look at torque.
Torque is what accelerates your vehicle. I always tell ask people how much power does your car engine have. Let’s say 100kW@6,000rpm. If you drive your engine up to 5,500rpm slowly, then stamp 100% on the gas pedal, how hard does it accelerate? No too good. Now do the same test at 2,500rpm, the acceleration is far better. Look at a dyno graph of you engine, and you will notice you have around half the power at 2,500rpm than at 6,000rpm, yet the car accelerates at least twice as good. So power doesn’t give you the performance you think it’s giving. If you put an accelerometer in your vehicle, you will notice that the acceleration matches your torque curve. Peak torque is generally between 3,500rpm and 4,500rpm on a normally aspirated engine, and this is the rev range you feel the most acceleration. Higher torque in the lower rev ranges and maintaining it over the rev range provides a higher efficient engine. We have proven it.
Over the years there have been a lot of knockers, but we have independently tested and produced the figures to back up our claims. There has been a huge amount of engines been developed out there who claim huge gains in efficiency. We are the only company to my knowledge that has proven their claims.
Thanks again for your interest and comments… keep them coming.
Regards
Brad Howell-Smith
Chairman/Inventor
Revetec Holdings Limited
Oh yeah, I forgot to mention the fuel economy. Even though our engine provides incredible fuel efficiency of 207g/(kW-h) or 39%, the engine’s increased low down torque enables you to accelerate the same as a conventional engine, but at lower rpms. The lower the rpms, the less fuel being used (less volume swept per minute). In tests we proved this.
Regards
Brad Howell-Smith
Chairman/Inventor
Revetec Holdings Limited
The Revetec engine design doesn’t go far enough! Where is the variable compression, the electric motor/generator, the electromagnetic valve actuators and the turbo compounding? Seriously they could do much better!!!! I know I can.