came across this today, just wondering what people think.....



its a motor developed in Australia, has no crank or connecting rods, puts no load on cylinder walls and claims to have more efficiency then the average gasoline motor.......heres a link to their web site.....id like to know peoples thoughts.

http://www.revetec.com/

 

Runs an A/F of 15.2~14.5??? Pretty wild!

 

There are tons and tons of "experimental" engines out there with similar setups. Detroit/Japan, however, will take some time to step away from engines theyve had 90-100 years developing now.

 

looks sick

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Combustion Contraption &raquo;</TD></TR><TR><TD CLASS="quote">There are tons and tons of "experimental" engines out there with similar setups. Detroit/Japan, however, will take some time to step away from engines theyve had 90-100 years developing now.

</TD></TR></TABLE>


well with current gas prices, i think the market is ripe for the picking........but i agree. I think its all a political thing to. I heard a long time ago that someone developed an extremely efficient motor and ford or gm, i don't remember who, bought the rights to it and shelved it.......i think technology is there for a better motor. Still the concept of this one is pretty neat, with the majority of the power being realized at a lower rpm. The thing acts like a diesel on pump gas.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Godspeed07 &raquo;</TD></TR><TR><TD CLASS="quote">a motor developed in Australia, has no crank or connecting rods, puts no load on cylinder walls and claims to have more efficiency then the average gasoline motor.......heres a link to their web site.....id like to know peoples thoughts.

http://www.revetec.com/</TD></TR></TABLE>

I'll still boost that ****

 

Hi I like to study alternative engine designs, I've had some discussions with this inventor. Sorry for the long post.

There is a lot of BS on that site, just read this document properly...
http://www.revetec.com/pdf/X4v...7.pdf

To be honest I'm not sure there is anything to get excited about, sure it's different but so what:
No. of Cylinders 4
Engine Capacity 2382cc
Bore 108mm
Stroke 65mm
Over/Under Square Ratio 1.66:1
Compression Ratio 9.5:1 (but on the BSFC page it is stated at 10:1)
Max Power 69kW(92hp)@3,600rpm
Max Torque 202Nm(149lbft)@3,000rpm (on that PDF, on the BSFC PDF one it maxed at 176Nm)
Induction Normally Aspirated
No. of Valves 8
Valve Arrangement OHV 2 per Cylinder
Valve Size In:44mm Ex:39mm
Valve Lift 10mm
Camshaft Type 2 x Single Hydraulic
Camshaft Profile Aircraft (3,000rpm)
Engine Management Haltech E8
Fuel Injection Type Sequential Multipoint
Fuel Injector Type Subaru EJ20
Ignition Type Dual Waste Spark
Ignition Coil Type EC Custom
Spark Plugs Type NGK - DCPR8E
Spark Plug Gap 1.1mm
Engine Proto. Dry Weight (dressed) 131kg
Estimated Prod. Weight (dressed) 105kg
Engine Width (dressed) 740mm
Engine Height (dressed) 550mm
Engine Depth (dressed) 460mm

BMEP is another figure they like to throw around, on one PDF they claim 10.5, on the BSFC it is 9.29, clever to seperate the figures into different reports all on the same engine.

Here is the BSFC pdf:
http://www.revetec.com/pdf/REV...l.pdf
Notice the exhaust gas temps, I dunno thats a little hot for only 3500rpm, who knows maybe those pistons inside are screaming along at 3 times that speed since the trilobe design pushes them up and down 3 times for every revolution?

There are many funny bits in the first PDF, if you don't pick them up just read it again. Massive width of 740mm for the 65mm stroke motor and that is with pushrods and an X design, if it is a boxer it will be even wider, the X-design is not great for handling since it will lift the center of gravity quite a bit, a boxer with a typical DOHC system could be near 1000mm! and longer because you need two cam/crank setups. Brad might believe in his engine but he is certainly not a real automotive engineer, someone with an idea that got some government money and investors, and is pushing a product that won't ever take off, because it simply isn't any good...

Check their share price history: http://www.nsxa.com.au/prices_...e=RVC

I want to see this engine explode at 7000rpm


Modified by The Poisoned Apple at 11:10 AM 7/15/2008

 

some great points there.......however you have to hand it to the guy for innovative design. If nothing else is "better" per say, then a conventional motor, the fact that there is little to no load on the cylinder walls which could potentially result in a much longer lasting motor is pretty cool in my eyes. Im not an engineer so in all honesty what do i know right??? I just like discussion about these types of things. From what i gather, hes making 92hp and 149ftlbs of torque on an 8 valve 9:5.1 compression N/A motor. Thats comparable to any other 2.4 liter motor on the market as far as torque goes. Well up the compression, add a few more valves, develop the head to flow more efficiently, add vvti, or vtec to the mix and i think you have the makings of a great motor........you could be right, those pistons could be screaming........but maybe they aren't. In addition the motor is running much leaner which may explain the hotter exhaust temps. I dunno i kinda like it personally

 

Hi guys.

Hehehhehe! It's funny to see people making performance comparisons between our aviation engine which is using limited top end and industry used technology for that market, against what you guys know of your engines in your vehicles that have very highly technical features.

The testing we performed recently was our aircraft engine, with two valves and pushrods (reason being this is mostly a standard for aircraft, as they don't like to use belts or chains etc.) we achieved a BSFC of 207g/(kW-h). This testing was designed for the exact operational speed of an aircraft engine at which the tweaks of the engine were carried out for that operational speed.

We are working on a V4 automotive engine at the moment which will hopefully provide all you are wanting to see in size, weight, performance and efficiency.

Here's a sneak preview of the kind of engine we are working on.




Cheers
Brad



Modified by revetec at 3:35 PM 7/16/2008

 

wasn't that picture made using a siemens program?? By the way im excited to see what this thing can do......of course we are all looking to find out power figures as well as other things such as efficiency etc.

 

Yes, I use Solid Edge V20 from Siemens/UGS, and the render was done within Solid Edge V20 (VS+)

Well at the moment we are producing more kW per gram of fuel than any other internal combustion petrol engine.

Cheers




Modified by revetec at 6:54 PM 7/16/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Godspeed07 &raquo;</TD></TR><TR><TD CLASS="quote">


well with current gas prices, i think the market is ripe for the picking........but i agree. I think its all a political thing to. I heard a long time ago that someone developed an extremely efficient motor and ford or gm, i don't remember who, bought the rights to it and shelved it.......i think technology is there for a better motor. Still the concept of this one is pretty neat, with the majority of the power being realized at a lower rpm. The thing acts like a diesel on pump gas. </TD></TR></TABLE>

A professor Yule Brown ( Browns Gas ) invented a conventional engine running on hydrogen back in the 60's that only used water, had a safe conversion unit, made more power then petrol and the only bi product was water. The technology exists and has done for near 40 years, but none of us will see it till the governments can figure out how to charge us to run our vehicles on water

Everytime i hear pollution this environment that i think what a load of crap.

The RevTech is a very nice peice and its good to see you guys are still devoloping the engine and its efficency.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slaz &raquo;</TD></TR><TR><TD CLASS="quote">

A professor Yule Brown ( Browns Gas ) invented a conventional engine running on hydrogen back in the 60's that only used water, had a safe conversion unit, made more power then petrol and the only bi product was water. The technology exists and has done for near 40 years, but none of us will see it till the governments can figure out how to charge us to run our vehicles on water

Everytime i hear pollution this environment that i think what a load of crap.

The RevTech is a very nice peice and its good to see you guys are still devoloping the engine and its efficency. </TD></TR></TABLE>

thats probably what i was thinking about.....its funny theres a "that 70's show" episode where hyde was like....."this guy, made a car that runs on water mannnnn"........they of course were sitting around the doobie table, but i guess it was all true....and the "man" (government) is trying to keep progress down......its all a conspiracy...

 

Heheheh! It's not that simple. Firstly you have around 80% losses converting water to hydrogen. Secondly, the amount of hydrogen you can practibly store on a vehicle can give up to 120 miles of driving only (same as fuel cells) Thirdly, with 40% losses in hydrogen production and 70% losses from existing engine technology, it makes it overall very inefficient, and you cannot produce enough hydrogen on board to run an engine continually as the engine cannot produce enough power to sustain hydrogen production, or it would be greater than perpetual motion, which is just silly. Do some acurate and thorough research on what you say before making comments please.

There is no doubt that engines can run on Hydrogen although over about 8% supplement to petrol causes dry heat so much it causes embrittlement into all metal components exposed to combustion over time causing very bad engine failure. It is possible to increase efficiency of petrol and diesel engines by supplimenting hydrogen but only about 4-6% hydrogen without much trouble, which can give real benifits to engine efficiency. Remember, water doesn't burn and it takes energy to convert it, which must be factored in.

Cheers
Brad

BTW. The engineer that took over Yule Brown's development after his death contacted me many years ago for a lengthy discussion, and I know all about his project, actually probably more than most people know.

Quote from Wikipedia:
OxyHydrogen: Automotive
See also: water-fuelled car and hydrogen fuel enhancement
Oxyhydrogen is often mentioned in conjunction with devices that claim to increase automotive engine efficiency or to operate a car using water as a fuel.

Many of these claims, prima facie, violate the Laws of thermodynamics. See Conservation of energy and Electrolysis of water:Efficiency.


Modified by revetec at 7:34 PM 7/16/2008

 

Fan of the Subaru are we? I bet a I have a few of those valve-cover gaskets in my toolbox...hehehe.
I've been following your progress for the past year or so. Kepp up the good work!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by revetec &raquo;</TD></TR><TR><TD CLASS="quote">Heheheh! It's not that simple. Firstly you have around 80% losses converting water to hydrogen. Secondly, the amount of hydrogen you can practibly store on a vehicle can give up to 120 miles of driving only (same as fuel cells) Thirdly, with 40% losses in hydrogen production and 70% losses from existing engine technology, it makes it overall very inefficient, and you cannot produce enough hydrogen on board to run an engine continually as the engine cannot produce enough power to sustain hydrogen production, or it would be greater than perpetual motion, which is just silly. Do some acurate and thorough research on what you say before making comments please.

There is no doubt that engines can run on Hydrogen although over about 8% supplement to petrol causes dry heat so much it causes embrittlement into all metal components exposed to combustion over time causing very bad engine failure. It is possible to increase efficiency of petrol and diesel engines by supplimenting hydrogen but only about 4-6% hydrogen without much trouble, which can give real benifits to engine efficiency. Remember, water doesn't burn and it takes energy to convert it, which must be factored in.

Cheers
Brad

BTW. The engineer that took over Yule Brown's development after his death contacted me many years ago for a lengthy discussion, and I know all about his project, actually probably more than most people know.[/i]</TD></TR></TABLE>

Your right about all those factors Brad, and whilst you might know more then most, doesnt mean you know more then all, ever meet the man?

I have and did and was fortunate enough after being generally interested in it to get a good understanding of what it was all about and its potential with devolopment, attemps on his life were not for nothing and only stopped once all information was made public on the net for all to see, therefore the need was no longer there.

More efficent petrol engines are always going to be devoloped as fuel stores dry up as do the costs of petrol but you dont see or hear of manufactures doing what u are or better with their unlimited resources and or buying you or your principals do you, yet their playing with hydrogen and fuel cell's, funny that so the technology cant be as useless as it seems can it?

So dont assume the shortcomings of it, will they be there in the future as you never know what ideas and materials are around the corner or already exist.

Im not going to get into a tech debate with you and even after praising your efforts and product in the previous posts and meeting you once in Sydney, cant help but think less of you now, but maybe your thing is coming on forums and putting people down.........whilst blowing your own.




Modified by Slaz at 3:00 PM 7/17/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slaz &raquo;</TD></TR><TR><TD CLASS="quote">

A professor Yule Brown ( Browns Gas ) invented a conventional engine running on hydrogen back in the 60's that only used water, had a safe conversion unit, made more power then petrol and the only bi product was water. The technology exists and has done for near 40 years, but none of us will see it till the governments can figure out how to charge us to run our vehicles on water

Everytime i hear pollution this environment that i think what a load of crap.

The RevTech is a very nice peice and its good to see you guys are still devoloping the engine and its efficency. </TD></TR></TABLE>


right on

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slaz &raquo;</TD></TR><TR><TD CLASS="quote">Im not going to get into a tech debate with you and even after praising your efforts and product in the previous posts and meeting you once in Sydney, cant help but think less of you now, but maybe your thing is coming on forums and putting people down.........whilst blowing your own.
</TD></TR></TABLE>

I'm not putting anyone down. I said that hydrogen can increase efficiency as a supplement with diesel and gasoline fuels. I actually like hydrogen and Brown Gas. But on its own it has short comings which I identified. I am able to technically debate it further if you want.

Anyway I'm not here to promote my technology, just popped in for a look and a comment. I'm not selling anything to anyone on this forum and I only visit forums to listen, learn and sometimes educate. If the forum members don't want me to comment or post I wont. Some other forums has invited me to contribute which I have and in doing so I've tried not to breach forum rules.

I only posted the images to show to members that we are designing engines to fit better suited motor vehicle requirements in power and performance.

Cheers
Brad

 

Brad are there any harmonic or gear whine issues with the gear to gear application?

 

I have gear analysis software that I use so I can keep the gearset speed below the point of audible whine. Saying this, in previous engines we always used helical gears previously to reduce this risk further. In the last 3 engines we used straight cut spur gears and we have not experienced any audible gear noise, although the analysis software said we would not have any, I really expected to hear something, but no gear noise.

The gears we use are hardened and ground.

 

glad to hear I always hated hearing those timing gear drive sets on SBC's.

 

Have you and your colleagues considered making a modern sleeve-valve aviation engine? In terms of mechanical efficiency it definitely has the upper hand by not having any valve motion. Since it is purely crank and gear driven, you do not have any chain or belts to fashion. Some argue that they can achieve a greater volumetric efficiency (although I haven't seen any data that suggests this to be definitely true when compared to the best piston engines). The Napier versions in the 1930's had BMEP values in the ~2500+ kPa range, which is greater than modern day Diesel's. More reliable at sustained power as well!

Just a curious thought.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Godspeed07 &raquo;</TD></TR><TR><TD CLASS="quote">some great points there.......however you have to hand it to the guy for innovative design. If nothing else is "better" per say, then a conventional motor, the fact that there is little to no load on the cylinder walls which could potentially result in a much longer lasting motor is pretty cool in my eyes. Im not an engineer so in all honesty what do i know right??? I just like discussion about these types of things. From what i gather, hes making 92hp and 149ftlbs of torque on an 8 valve 9:5.1 compression N/A motor. Thats comparable to any other 2.4 liter motor on the market as far as torque goes. Well up the compression, add a few more valves, develop the head to flow more efficiently, add vvti, or vtec to the mix and i think you have the makings of a great motor........you could be right, those pistons could be screaming........but maybe they aren't. In addition the motor is running much leaner which may explain the hotter exhaust temps. I dunno i kinda like it personally </TD></TR></TABLE>

Yup i certainly agree it is a lot of good work and it is very cool that it runs so well, is piston skirt wear really an issue? I think modern motors last pretty long and are cheap to rebuild, anyway the miniscule improvement in piston wear and friction reduction isn't anything worth getting excited about, of course one can see benefits as well, short rigid motor, no cam in theory that means high rpm and a motor that can handle a lot of power, more efficient power transmission from piston to lobes but too many drawbacks. I looked in the gallery and the X4v2 seems to be geared correctly, so the motor seems to be running extremely lean(altho im not a tuner), it also seems like it would "handle" detonation better than a normal engine(not sure what those bearings inside the trilobe "followers" look like after though) but how long before you start melting stuff?

Common Brad you are the one comparing this motor to automotive engines, in your PDF's published on your website you compared the X4 to car engines.
http://gas2.org/2008/06/26/low...onomy/
You can read all about your comparisons and claims with car engines there too... Double your mileage, "The X4v2 has a huge amount of torque over a much larger range of rpm’s than a conventional internal combustion engine." How is a range of 1000-3000rpm bigger than 1500-5500rpm for a normal engine?

It surely can't be that much more effort to put in "automotive cams" and spin it to 6000rpm and see what it does, just on the dyno for fun. In the V4 design you are going to lose efficiency, and a lot of it because you double the weight of your conrods and trilobes. Furthermore the weight of the engine itself will increase as well reducing your HP/Kg, getting close to or perhaps more than a normal engine. One of the big problems for manufacturers would be tolerance, the trilobe and conrods and followers need to be extremely exact (or do you have a way to compensate for this?) to follow the lobes perfectly without losing contact, if it does it is going to start hammering.

Brad how much does the rotating cam lobes and required gearing weigh?
How much does the "conrods", "followers" and pistons weigh?

Have a good weekend, oooh it's a F1 weekend!

 

You seriously need to stop calling it the "world's most efficient internal comubstion engine" if you're only getting 39.5% efficiency. You do realize diesels can get over 48% efficiency don't you? Or is it you don't realize they're internal combustion engines?

 

In so I can learn more.