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Open ForumsThe Open forum was created for people to discuss anything else Non-Moto related. Just about anything goes! Please remember this is a loosely moderated area. If you do not have thick skin. We suggest you stay out of here.
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.
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.
X4v2 SchematicThe 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.”
Revetec AnimationWhat 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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Repairing it, it looks like the whole thing would have to be taken apart to do anything. So when it breaks you pay twice as much to fix it if not more.
It doesn't actually look too dissimilar (in function) to any other internal combustion engine. Looks like the triangle system in the second picture would replace the cam chain and cams.
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Everyone seems normal until you get to know them.
Clever idea making power with both strokes of a piston ("up and down"). It doesn't look like it would really be all THAT MUCH more trouble to work on, at least for most common maintenance. The only trouble would be doing internal engine repairs, which is a bitch anyways and well beyond the scope of most home mechanics on modern cars as it is. If built to current standards its likely not an issue that an original owner would ever encounter.
Edit to add: In terms of more routine maintenance consider that it appears to be all gear driven. No timing belt. Also no connecting rods or crank shaft. The bearings that turn the "crank" appear to be external to the actual piston bore and combustion chamber, much easier to fix and much less likely to fail in that environment. It MAY (emphasis on MAY) prove to actually be less maintenance intensive than a traditional design. Only time will tell on that one.
Last edited by HighsideSV : 07-02-2008 at 02:49 PM.
after not too much thought, this is just an overly complicated boxer engine. i do not see any real benifit to the solid connecting rod and counter rotating lobe things to justify the additional complication over a standard crank and con rods.
although the piston would make power differently through its stroke. hmmm
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...Until we see each other once more on the path along the way
Low Cost engine doubles fuel Economey, Makes same power!
Reminds me of 1930's aircraft engines
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