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There is no doubt to the efficiency of gas turbine engines. The problem is that they dont suit automotive usage due to many reasons, initial cost, operation characterisitcs and the like, plus they do not like fuel delivery inconsistancies. They are very good and efficient for power generation and in many cases now are around 50% thermal efficient on modern units.
Cheers
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I have a question about the revetec design...
How does it make more power?
I mean I can see how it makes roughly 3X the amount of torque but it does so at 1/3 of the RPM making the same power.
How is it more efficient?
I mean normally running at lower RPM is more efficient but you pistons and connecting bars are moving at 3X the output shaft speed, that increases friction from moving the intake charge into and the exhaust out of the cylinder so quickly. Also accelerating the pistons, connecting rods, and valvetrain to the same high speeds as other engines doesn't gain anything.
I am having trouble seeing the advantages (or at least the reasons and proof of having certain advantages)
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this where the bike dudes hang out then
[IMG]http://www.costablancaexpats.net/pgal/albums/jokes/crap_scooter.jpeg[/IMG]
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Review previous Pages
Hightower99, for an explanation on teh technology, looks at their web site or read over teh previous 19 pages for an explanation, it is all there.
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[QUOTE=santostripoli]Hightower99, for an explanation on teh technology, looks at their web site or read over teh previous 19 pages for an explanation, it is all there.[/QUOTE]
I have read both and neither explain the technology in depth...
Neither offer satisfactory evidance of increased performance or even a reason for increased performance or efficiency.
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[QUOTE=santostripoli]
Is gas a viable alternative to petrol/diesel? No[/QUOTE]
Diesel and gasoline don't burn. The gas evaporating from it burn.
A gas turbine can runn on annything from LNG-heavy fuel oil. Jet engines is in theory the same as a gasturbines and they runn on something like diesel.
Study befour you post.
[QUOTE=santostripoli]
The Revetec engine appears to have [/QUOTE]
Apperars yes, but dos it? No.
[QUOTE=santostripoli](1) effeciency (power & torque)[/QUOTE]
Gasturbines has more torque and so dos steam engines and electric motors so what is your point?
[QUOTE=santostripoli](2) the flexibility to be integrated within existing engine platforms[/QUOTE]
after you changed the gear ratio yes.
[QUOTE=santostripoli](3) packaging effeciencies [/QUOTE]
Why? the stroke is only the radius off the crank and not the diameter like a traditional crank and boxers are not ideal for packaging unless you are making rear or mid engine cars.
[QUOTE=santostripoli](4) weight saving [/QUOTE]
minimal if anny
[QUOTE=santostripoli](5) fuel economy [/QUOTE]
profe?
[QUOTE=santostripoli]= a very exciting development in the development of the international combustion engine.[/QUOTE]
no
[QUOTE=santostripoli]Automotive companies get excited when there is a weight gain of 10kg; this engine will save more weight + improve effeciency + fuel economy.[/QUOTE]
maybe, no and no
[QUOTE=revetec]Dear stian1979, I think you should go back and read all previous postings before you just quote one part of a discussion.[/QUOTE]
I posted in this tread befour you did.
[QUOTE=revetec] we use the same. (ie. Two piston strokes per piston per RPM) [/QUOTE]
Don't insult my inteligense. I am a engineer.
you will have the same piston cycles as a convencial engine at 1/3 off the RPM.
why don't you post this engine off yours on the atlas forum? [url]http://forums.atlasf1.com/index.php[/url] and see it taken apart?
you don't dear do you?
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[quote=stian1979]why don't you post this engine off yours on the atlas forum? [URL="http://forums.atlasf1.com/index.php"]http://forums.atlasf1.com/index.php[/URL] and see it taken apart?
you don't dear do you?[/quote]
The revetec has come up many times in Atlas, along with many other alternatives for discussion.
Perhaps "dear" [B]you[/B] should adjust your attitude.
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[QUOTE=Matra et Alpine]The revetec has come up many times in Atlas, along with many other alternatives for discussion.
Perhaps "dear" [B]you[/B] should adjust your attitude.[/QUOTE]
OK I will.
Revetec will take over the market it aviation, travle in time and space to other solar systems and be the dominant powersource in the auto industry for the next 5000 years. Is that the attitude you want me to have?
And by the way it's done befour.
[IMG]http://www.prototype-design.com/images/caminez.jpg[/IMG]
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Have an open mind
[QUOTE=stian1979]Diesel and gasoline don't burn. The gas evaporating from it burn.
A gas turbine can runn on annything from LNG-heavy fuel oil. Jet engines is in theory the same as a gasturbines and they runn on something like diesel.
Study befour you post.
[COLOR="Red"][B]RESPONSE[/B][/COLOR]
We are talking about the commercial application of an engine for automotive, aviation & marine application here, not some niche application such as your beloved gas turbine. Perhaps you should take your engineering hat off and look at this proposition from a practical business application. You must view this subject from a hollistic perspective; you are too narrow minded. :D
[quote=stian1979]Gasturbines has more torque and so dos steam engines and electric motors so what is your point?
[COLOR="Red"][B]RESPONSE[/B][/COLOR]
How many cars out there run on gas turbines?
How many existing engine platforms can be retro-fitted with a gas turbine?
Think about the real world applications of this engine technology, not just from a single minded perpsective. Put your 'business mind' thinking cap on and review your comments, and then consider the world of possibilities with this Revetec technology.
We are all waiting for proof of concept data from the Revetec team; you are not the first to point this out. Lets wait for Brad and his team to release the data and then we can be as critical as we like. However, your argument about gas turbines mate is flawed. Gas turbines have no chance of any form of mass production for automotive/marine/aviation. The Revetec engine does (pending stats on the engine and the acceptability/viability of the technology).
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Stian,
Revetec have said they don't have the 3:1 gearing anymore (giving 3 times the torque at 1/3 the rpm, therefore the SAME power). They have said that was outdated information on their website. I have said their website is full of misleading information and should be corrected.
So what they are currrently saying is that their engine still has advantages and is better, but they have no test results to prove it yet.
So I am waiting for some conclusive test results before this topic can be discussed in a constructive manner.
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[QUOTE=santostripoli]Gas turbines have no chance of any form of mass production for automotive/marine/aviation.[/QUOTE]:rolleyes:
[url]http://www.rolls-royce.com/marine/products/diesel_gas_turbine/default.jsp[/url]
[url]http://www.rolls-royce.com/defence_aerospace/products/transport/t56/default.jsp[/url]
Again check befour you post.
[QUOTE=pneumatic]Stian,
Revetec have said they don't have the 3:1 gearing anymore (giving 3 times the torque at 1/3 the rpm, therefore the SAME power). They have said that was outdated information on their website. I have said their website is full of misleading information and should be corrected.
So what they are currrently saying is that their engine still has advantages and is better, but they have no test results to prove it yet.
So I am waiting for some conclusive test results before this topic can be discussed in a constructive manner.[/QUOTE]
they still have the gearing here. You can see the cams moving behind the flyweel [IMG]http://www.revetec.com/files/_images/RLX408-small.gif[/IMG]
dos it still have advantages? I gues yes and no.
If you turn a motorbike engine with your hand and a car engine with the same displasement the motorbike is a litle lighter to turn. It's calles ball bearing witch also the revetec has from what I has observed, but I could be wrong.
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[QUOTE=stian1979]:rolleyes:
[url]http://www.rolls-royce.com/marine/products/diesel_gas_turbine/default.jsp[/url]
[url]http://www.rolls-royce.com/defence_aerospace/products/transport/t56/default.jsp[/url]
Again check befour you post.
RESPONSE
What aspect of the phrase 'mass production' do you not understand? :confused:
Now you should check before you post and perhaps sit in the corner for 10 minutes and think about what you have said and when you are a good little boy you can come and join the rest of us in the playground :eek:
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1 Attachment(s)
[QUOTE=santostripoli][QUOTE=stian1979]:rolleyes:
[url]http://www.rolls-royce.com/marine/products/diesel_gas_turbine/default.jsp[/url]
[url]http://www.rolls-royce.com/defence_aerospace/products/transport/t56/default.jsp[/url]
Again check befour you post.
RESPONSE
What aspect of the phrase 'mass production' do you not understand? :confused:
Now you should check before you post and perhaps sit in the corner for 10 minutes and think about what you have said and when you are a good little boy you can come and join the rest of us in the playground :eek:[/QUOTE]
This forum software has gifted us with a 'Quote' feature. Makes posts a lot easier to read. Here is a picture showing where it is located:
[IMG]http://img266.imageshack.us/img266/283/quotetd2.jpg[/IMG]
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My response to stian1979
stian1979
As I have said before....Gas turbines are efficient but have a couple of characteristics not making it preferable for uses such as automotive. Firstly they are not too responsive down lower RPM ranges and are costly to produce due to the fine tolerances. Rover did use a gas turbine in one very short lived model but it was dropped due to the above reasons.
There is no doubt of their power/torque/rev range.
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On our website we have revealed our new X4 engine which will be completed and running soon. This engine is around 1/2 the size (Block is 160mm from front to back) and weight of the lightest 2.5 litre automotive engine on the market which is made by BMW.
The final drive ratio is the same as any other engine on the market. 2 strokes of the piston per 360 degrees rotation.
We have proven fuel efficiency in many tests (independently). The efficiency gain comes mainly from using the normal side thrust of the piston, and converting it to rotational force via the other cam. We also increase the length and amount of time the piston has good leverage to the output shaft. All this is basic mechanics. We then accelerate the piston at rates that suit combustion most efficiently, that a conventional engine can not achieve because of its design limitations. This has resulted in better combustion and far less fuel and emissions on cold starting. We have achieved a very flat torque curve without the need and expense of variable cam timing and variable intake runner lengths.
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The engine design you have posted looks good at first glance by any novice. Firstly can I say that on a cam engine, if you exceed around 30 degrees contact angle to the cams from a vertical plane that the side thrust becomes too great and the efficiency and reliability drops. 300 single cam engines have been patented and not one has been successful due to this inherent problem. Secondly the engine shown, the piston moves in a sine wave acceleration which has been discussed on this topic. This is can only be efficient in engines with very high operating rev ranges such as 15 to 20 thousand RPMs.
BTW. The engine you posted has a gearing of 2:1 in it. 4 strokes of the piston to 360 degrees rotation and requires gearing to suit any automotive application.
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Your quote:
Why? the stroke is only the radius off the crank and not the diameter like a traditional crank and boxers are not ideal for packaging unless you are making rear or mid engine cars.
How about the WRX or many other Subaru cars?
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Your comment about weight savings....Weight savings is important. It means fewer materials. You might not know this but GM saved $0.5 million dollars by deleting one bolt out of one of its car models. We have reduced the weight from the lightest 2.5 litre which is made by BMW (171kg) to around 95kg. Almost half the materials. Lighter engines mean better handling cars.
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We don’t change the gear ratios in our automotive engines. A higher and lower revving engine can be achieved by changing the equivalent to a crank engine's rod/stroke ratio. All this by only changing 2 components on a four cylinder engine.
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Your quote:
Don't insult my inteligense. I am a engineer.
you will have the same piston cycles as a convencial engine at 1/3 off the RPM.
why don't you post this engine off yours on the atlas forum? [url]http://forums.atlasf1.com/index.php[/url] and see it taken apart?
you don't dear do you?
My response: Again you obviously haven't read the forum posts correctly because if you did, as an engineer myself it is very easy to understand. We have 2 strokes per rev...Exactly the same as a conventional engine.
By the way...It's intelligence…conventional….and dare.
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X4
Our new compact 2.4 ltre aviation engine. Technology will flow through to automotive applications.
[IMG]http://i84.photobucket.com/albums/k6/revetec/X4_400.jpg[/IMG]
As you can see...the flywheel is on the bottom shaft, not the shaft where the cams are. This has 2 strokes of each piston per 360 degrees of rotation, the same a a conventional engine.