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  #31  
Old 02-24-2006, 01:56 AM
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Matra et Alpine Matra et Alpine is offline
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Quote:
Originally Posted by stian1979
http://www.revetec.com/?q=taxonomy/term/20

read this and you see what I mean. They say they good more torque but it's a lie since it produce actually less torque per work cycle. The fuel should be the same since it's using engine comparison at same displacement and same cylinder pressure. It show better fuel efficiency at low rpm but this is due to bether flow in the valves since the engine has higher piston speed at same rpm than a convensional engine. so a convensional engine would have the same fuel efficensy at the same torque. Tehy only read out the data that make the engine look good.
Smaller lighter faster engines are generally MORE efficient as their are less losses. You conjecture has validity if the Revetec ends up with the linear mass movement of the "normal" engines, but it replaces some of that and most importantly increases the energy extracted from the piston movement by operating with no side force vectors from cranks. IF they can run the engine at optimum revs for efficiency BECAUSE it produces higher torque then it wins. That is their stated position and THEY DO claim BETTER fuel efficiency. I've not seen anything that backs up to the contrary. As I said I think you speculation uses "normal" limits and tries to apply them to REvetec. I dont agree they're comparable.
Quote:
The bearings I'm refering to is the ones transfering the power from the pistons to the big dishes I would call a crankshaft.
yep, and HOW is that different to a gudgeon pin in a "normal" engine ?
I'd also forgotten that they have alignment shafts that retain piston alignment so would suggest removal of "slap" allowing a much smaller skirt and possibly lower mass piston.
Quote:
Those shafts with those big cams and the mecanism to handle the contrarotating operation must be more heav than anny conrods.
How do you reach that conclusion ?
They are NOT subject to the needs of thinness of a conrod to be able move the piston. So they dont' need to be as substantially built. They are much shorter in throw too. The engine wins because it does NOT use a crankshaft -- which has counter weighted lobes -- and is more efficient in power extraction per combustion because there is no angular vector from a conrod.
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Boxers get oval more easy because the gravety pull the pistons down against he ground.
??? Who told you that ?
The effect of gravity is MINISCULE relative to the combustion forces in the engine
Quote:
Why is it only two brands in the worls using boxers? It has good balance and low center of gravety so why is it not more that use them?
PACKAGING. You get a WIDE engine hard to fit in.
Boxers are WIDELY used in light planes because then the packaging can actually be an advantage !! You dont' get many places where reliability and performance are any more important than a light aircraft
Boxers are a BIG win when you go air=cooled. But by the time you add a water jacket then a 4 isn't as efficient packaging as a straight.
Quote:
a inline will be lighter because it require less material since making only one bank conectet to the crankcase. A smal V will make the Banks share some material and big V vill make the engine more heavy because the banks no longer share anny material so it has to be conectd to the crankcase bye it's own. A boxer is practical a 180 degre V engine.
Boxer and V180 are different as boxer is opposed piston and naturally balanced in all configurations whereas a V180 isn't. But the packaging is similar. There is a small difference in weight in the block but it' s arguable that the bottem end is stronger in a boxer wieight-for-weight as you dont' need to build extra ribs to stop the crank twisting out the bottom of a "normal" block.
Quote:
Renult had a 110decre f1 engine but give it up because it become to heavy.
They went back to a more moderate angle.
NO, they coudln't control the VIBRATIONS that the unusual angle introduced.
Quote:
Know what I mean?
Some of what you say is valid but there is a counter argument for each of them that the Revetec design seems to have used. I have commented where I think you take the poor points that a crank based engine has and then assumed it applies to the Revetec esp with regard to the cylinders. With NO sideways forces during the cycle then theoretically the block requires less stiffening, less thickness less weight !!
THE big benefit the Revetec design goes for is the removal of the angular forces a crankshaft imparts. SO removing all the necessary design to cope with those stresses and wear.
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  #32  
Old 02-24-2006, 07:03 AM
stian1979 stian1979 is offline
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Quote:
Originally Posted by Matra et Alpine
Smaller lighter faster engines are generally MORE efficient as their are less losses. You conjecture has validity if the Revetec ends up with the linear mass movement of the "normal" engines, but it replaces some of that and most importantly increases the energy extracted from the piston movement by operating with no side force vectors from cranks. IF they can run the engine at optimum revs for efficiency BECAUSE it produces higher torque then it wins. That is their stated position and THEY DO claim BETTER fuel efficiency. I've not seen anything that backs up to the contrary. As I said I think you speculation uses "normal" limits and tries to apply them to REvetec. I dont agree they're comparable.

yep, and HOW is that different to a gudgeon pin in a "normal" engine ?
I'd also forgotten that they have alignment shafts that retain piston alignment so would suggest removal of "slap" allowing a much smaller skirt and possibly lower mass piston.

How do you reach that conclusion ?
They are NOT subject to the needs of thinness of a conrod to be able move the piston. So they dont' need to be as substantially built. They are much shorter in throw too. The engine wins because it does NOT use a crankshaft -- which has counter weighted lobes -- and is more efficient in power extraction per combustion because there is no angular vector from a conrod.

??? Who told you that ?
The effect of gravity is MINISCULE relative to the combustion forces in the engine

PACKAGING. You get a WIDE engine hard to fit in.
Boxers are WIDELY used in light planes because then the packaging can actually be an advantage !! You dont' get many places where reliability and performance are any more important than a light aircraft
Boxers are a BIG win when you go air=cooled. But by the time you add a water jacket then a 4 isn't as efficient packaging as a straight.

Boxer and V180 are different as boxer is opposed piston and naturally balanced in all configurations whereas a V180 isn't. But the packaging is similar. There is a small difference in weight in the block but it' s arguable that the bottem end is stronger in a boxer wieight-for-weight as you dont' need to build extra ribs to stop the crank twisting out the bottom of a "normal" block.

NO, they coudln't control the VIBRATIONS that the unusual angle introduced.

Some of what you say is valid but there is a counter argument for each of them that the Revetec design seems to have used. I have commented where I think you take the poor points that a crank based engine has and then assumed it applies to the Revetec esp with regard to the cylinders. With NO sideways forces during the cycle then theoretically the block requires less stiffening, less thickness less weight !!
THE big benefit the Revetec design goes for is the removal of the angular forces a crankshaft imparts. SO removing all the necessary design to cope with those stresses and wear.
If I got a normal crankshaft and get 100Nm at 1000rpm and a normal crankshaft that get 290Nm at 3000rpm would you then say it's a bether engine? You cant compare two engines with same stroke at diferent piston speed. If the revetec has only 1/3 of the revelution it stil have the same piston speed. At low speed it will show a bether fuel comsumption because it has a piston speed that alow it to fill the cylinder more efficiant, but average it will have the same fuel comsumtion as a normal engine.

The bearings on a normal piston and rod conection the movement is only 2cm per revelution since it only go back and forvard. The revetec has to roll all the way along the crankshaft rotation witch mean it has to travle 1/3 of the distance of the shaft per work cycle.

That delta shaped shaft has to be heavy! and don't tell me they wont nead a extra gear mecanism to runn those contra rotating.

Alfa tryed a 12cyl boxer in F1 and it did not win anny championship (it did not prove reabile)

I read about revetec a couple of week's ago and the more I think the less I like it. If I use a normal engine and runn it at 3 times the revelution and use a 3:1 gearbox I will have the same results as this guys did - I don't nead to waste time on all that engineering.

It's a funn project, but so was my steam engine
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  #33  
Old 02-24-2006, 10:26 AM
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Quote:
Originally Posted by stian1979
If I got a normal crankshaft and get 100Nm at 1000rpm and a normal crankshaft that get 290Nm at 3000rpm would you then say it's a bether engine?
Depends where the other one delivers 290Nm ?
By only takign one variable it creates a false impression.
I'm not sure what you are trying to say.
Quote:
You cant compare two engines with same stroke at diferent piston speed. If the revetec has only 1/3 of the revelution it stil have the same piston speed.
NO IIRC they run smaller displacement and use the swept volume to do comparisons.
Quote:
At low speed it will show a bether fuel comsumption because it has a piston speed that alow it to fill the cylinder more efficiant, but average it will have the same fuel comsumtion as a normal engine.
Where do you ahve the evidence for that ?
Quote:
The bearings on a normal piston and rod conection the movement is only 2cm per revelution since it only go back and forvard. The revetec has to roll all the way along the crankshaft rotation witch mean it has to travle 1/3 of the distance of the shaft per work cycle.
Their is rotation in the gudgeon pin and FULL rotation on the crankshaft AND the main journal.
Mating surfaces and materials are what makes for bearing resistance and wear.
Again, it's not clear what you are trying to say.
Quote:
That delta shaped shaft has to be heavy! and don't tell me they wont nead a extra gear mecanism to runn those contra rotating.
Why is it heavy ? There is no rationale for reaching that conclusion. You dont' knwo the materials or the tesile strenght requriements. The "extra" gear is there and as reported in many artciels the "bottom end" fo the Revetec is signifiacnlty lighter than it's coutnerparts. If you really need me to confirm that I'm sure I can find the original press releases -- in fact it's propbably up here on UCP
Quote:
Alfa tryed a 12cyl boxer in F1 and it did not win anny championship (it did not prove reabile)
So Alfa ( actually blame Subaru it never really had any chance to be developed to prove itself ) didn't make it work and so all flat 12s are bad ? hmm Ferrari WON CHAMPIONSHIPS with a flat 12 and the greatest sportscar of all time the Posrsche 917 used a flat 12
Quote:
I read about revetec a couple of week's ago and the more I think the less I like it. If I use a normal engine and runn it at 3 times the revelution and use a 3:1 gearbox I will have the same results as this guys did - I don't nead to waste time on all that engineering.
yeah right.
THe BIGGEST issue in engines is the piston crontrol and the crankshaft componetnry. The Revetec is one of many that are utilising modern methods and materials to provide different linkages not possible in the past. They've published numbers better than alternatives and have a deal with Honda to build in China.
Quote:
It's a funn project, but so was my steam engine
Whether it ends up a niche or mainstream it has some clear benefits ( which you've ignored/misunderstood )
AS said earlier, nobody is going to bring out an engine twice as powerful or efficient as any other competitor. Engine design isn't about that anymore that all happened 80 years ago But this does have definable engineering improvements and it woudl be nice to see it flourish and give options.
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  #34  
Old 02-24-2006, 08:26 PM
stian1979 stian1979 is offline
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Quote:
Originally Posted by Matra et Alpine
Depends where the other one delivers 290Nm ?
By only takign one variable it creates a false impression.
I'm not sure what you are trying to say.

NO IIRC they run smaller displacement and use the swept volume to do comparisons.

Where do you ahve the evidence for that ?

Their is rotation in the gudgeon pin and FULL rotation on the crankshaft AND the main journal.
Mating surfaces and materials are what makes for bearing resistance and wear.
Again, it's not clear what you are trying to say.

Why is it heavy ? There is no rationale for reaching that conclusion. You dont' knwo the materials or the tesile strenght requriements. The "extra" gear is there and as reported in many artciels the "bottom end" fo the Revetec is signifiacnlty lighter than it's coutnerparts. If you really need me to confirm that I'm sure I can find the original press releases -- in fact it's propbably up here on UCP

So Alfa ( actually blame Subaru it never really had any chance to be developed to prove itself ) didn't make it work and so all flat 12s are bad ? hmm Ferrari WON CHAMPIONSHIPS with a flat 12 and the greatest sportscar of all time the Posrsche 917 used a flat 12

yeah right.
THe BIGGEST issue in engines is the piston crontrol and the crankshaft componetnry. The Revetec is one of many that are utilising modern methods and materials to provide different linkages not possible in the past. They've published numbers better than alternatives and have a deal with Honda to build in China.

Whether it ends up a niche or mainstream it has some clear benefits ( which you've ignored/misunderstood )
AS said earlier, nobody is going to bring out an engine twice as powerful or efficient as any other competitor. Engine design isn't about that anymore that all happened 80 years ago But this does have definable engineering improvements and it woudl be nice to see it flourish and give options.
This revetec has same displasement as a normal engine. so at 1000RPM it's going to do the same work as a convensional engine at 3000RPM
But the average Nm output is only 2,9 of what a normal engine can do at the same RPM. Why? ask yourself this.

Evidence I find trough experience and reading betwen the lines.

how long is the distance around the camprofile on revetec's crank? the bearing on the pistion has to go this distance in case you did not notice.

Tradisjonal bearings only nead to travle a short distance and then back in the connection at the pistion and the distance round the crank that is short compared to the revetec.

This statement say it all.
Quote:
Originally Posted by revetec
The power output is similar to a conventional engine, but given that the significant improvement in torque output is almost three times that of a conventional engine
kW=Nm x RPM
Sorry but it's not posible.



I can at least tell you that it's more heavy than a normal crankshaft can be made.

Ferrari, meclaren and others make supercars with v engine. Why not the boxer? The disanvantage of space is gone when you have mid engine cars.
They get a lower center of gravety so why not use it? You can only refear to 1 race car doing good on the track with a boxer?

Why was this linkage not posible in the past?
So just because it's build in China it's good? Newer heard that one befour.

Otto and Diesel was engineer's so they knew what they where doing and they did it well.
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  #35  
Old 02-24-2006, 08:53 PM
stian1979 stian1979 is offline
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I found this on a other forum I'm a member of 3 week's ago that I think it's a good statement. It's from the FIA forum.

Quote:
Revetec is another example of a crap engine idea turned expensive development project. More victims of the torque uber alles mentality, and again fleecing large numbers of uniformed investors because of it.

They have a boxer engine with all the weight and bulk penalties associated with doubling up on cams, blocks, heads, manifolds etc. (There is a reason why boxers are not the standard engine format). To this they add a cam drive system for the pistons, with huge bearing issues. In essence all they are doing is replacing the crankshaft with a much trickier dual counterrotating three lobed camshaft.

So now they are crowing about getting three times the torque. Like that is some kind of miracle when you have three times as many piston strokes per crankshaft revolution! And they have only managed to get 150Nm out of a 1.4l engine (equivalent to about 35Nm per litre from a conventional engine or one third that of a good racecar engine (110Nm/litre) at a maximum speed of 2600 rpm (because of course the pistons are going at 7800 rpm at that speed).

But of course they haven't told the world that that is the limit in terms of their rpm. Or that a good inline four will produce three times the power they have achieved, or that high torque/low rpm is bad in that it means a much heavier and more expensive clutch and gearbox. Or that the piston driving bearings are spinning at huge speeds and are likely to pound themselves and the cam to pieces in short order.

There should be a website created to debunk idiot ideas like these. Or maybe I should loosen my morals and become the one parting the stupid people from their money.

End of rant
I think it neads bether explenation than this.
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  #36  
Old 02-25-2006, 06:47 AM
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Quote:
Originally Posted by stian1979
This revetec has same displasement as a normal engine. so at 1000RPM it's going to do the same work as a convensional engine at 3000RPM
That ignores the problem that the angular conrod has in losses in a"normal engine". The Revetec is one of a number of "new" ideas being explored just now that address that significant loss. It's THAT that makes oval cylinders BTW
Quote:
But the average Nm output is only 2,9 of what a normal engine can do at the same RPM. Why? ask yourself this....Evidence I find trough experience and reading betwen the lines.
That's the issue "evidence" is from everyone reading between lines and applying "normal" engine layout issues to IT.
Quote:
how long is the distance around the camprofile on revetec's crank? the bearing on the pistion has to go this distance in case you did not notice.
Wrong. The important point about a bearing is it's "contact" surface area. The actual points that has force applied to it. THAT has to either be on rollers or on pressurised lubricant. The issue the Revetec has is that you cant' build up an oil surface the way a rotating journal does. Bu we have new materials It's "pseduo science" like that that raises the question marks over the comments
Quote:
Traditional bearings only nead to travle a short distance and then back in the connection at the pistion and the distance round the crank that is short compared to the revetec.
IRRELEVANT.
You need to learn a bit more about bearings See comment above.
Quote:
This statement say it all.
kW=Nm x RPM
Sorry but it's not posible.
aha, the "ideal" engine>?
And why do engines NOT achieve the "perfect" numbers ?
Why are some engines more "efficient" and get closer than others ?
Yep. Think it out. As I have said the thing the Revetec is trying to deliver is the recovery of the loss in power from the operation of a crank. A significant loss and wear factor in an engine.
Quote:
I can at least tell you that it's more heavy than a normal crankshaft can be made.
Seriously, You WEIGHED a crank ?
Look at the lobes opposite to the pistons for balance !!
It clearly have to find you the quote rather than taking my word that I'd read an early press release saying the bottom end was lighter Did you search the previous UCP posts ??
Quote:
Ferrari, meclaren and others make supercars with v engine. Why not the boxer? The disanvantage of space is gone when you have mid engine cars.
Well done --- PACKAGING
NOT the engine per-se --- as I said.
Quote:
They get a lower center of gravety so why not use it? You can only refear to 1 race car doing good on the track with a boxer?
Reading ? ....... PACKAGING ... the boxer engine prevents a race car from using ground effects and body venturis because it's in the way. It works reasonably well in a WRC rally car but does give problems in locating other things -- and hence the Subarus propensity for tearing intercoolers off being limited on placement
Quote:
Why was this linkage not posible in the past?
Materials. Computing power to innovators to do EAD and stress analysis.
( See the Polish moving piston valves engine that the guy built in his garage L) )
There are many innovators out there trying the new ideas that in theory address limitation of our current designs.
It goes on all the time. The difference is that thanks to the internet we can see, explore and critique these solutions in a way not possible in the past.
Quote:
So just because it's build in China it's good? Newer heard that one befour.
Now THAT is just a stupid response, isn't it.
HONDA is the company reputedly in the deal.
Tells a lot on your thinking process that you ignored that it might be a MAJOR PLAYER and instead tried to make it sound negative because it was China
All it did was remove respect for your comments.
Quote:
Otto and Diesel was engineer's so they knew what they where doing and they did it well.
And modern engineers ARENT for what reason ?
And what about all those hundreds of engineers who were developing engines at the same time ? How much do you know about engine development and history ? Watt, Moorland, Brown, Matteucci, Stirling, the list is HUGE.
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  #37  
Old 02-25-2006, 07:02 AM
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Quote:
Originally Posted by stian1979
I found this on a other forum I'm a member of 3 week's ago that I think it's a good statement. It's from the FIA forum.



I think it neads bether explenation than this.
Sorry but "doubling up on cams" is one of theose STUPID responses I read so many times from folks who have never built anything

Lets take an engine that needs 2 valves per cylinder so we need 8 cam lobes on a 4potter.

If you used a pushrod then it's a no brainer, no difference If hte engine doesn't rev hard that's a distinc possibility

If we assume worst cases -- ie over head cam then you need a drive pulley - which is VERY light and then the 4 lobes and the 4 connecting shaft sections in each head. SO the only difference is the pulley and once shaft connecting section. NOT A LOT

If you go twin cam to get optimum valve angles then it's 2 extra pulleys and 2 extra connecting shaft piece ( ie abtou 1" long, 1/2" diameter. )

SO sorry, it's RUBBISH to harp on about all this "extra weight"

As someone who has spent too many hours in garages and workshops trying to minimise weight in race/rally engines it's a NONSENSE to make multipel cams out to be a disadvatage. the decision to go multile VALVES carries the penalty not signifactnly where you put them

THe writer also confuses efficiency and power.
IF you can make an engine 5% more efficient then revs etc are irrelvant as you then use gearing to make that engien operate in that optimum area. It's. I suspect, why they went for pumps initially as they are run at their optimum efficiency for long times, same with aircraft engines. Cars with proper CVTs are the same.
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  #38  
Old 02-25-2006, 10:17 AM
stian1979 stian1979 is offline
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Are you the designer of this pice of crap?
You try to defend something that annyone can see is a hopeless idea.
Do you know how mutch is lost in a engine because of friction?
It's nothing compared to what you loss in heat radiation, coolong water and heat trough exhaust. It's a none exsisting problem.
If someone want's seriosly to make some diferense they would put there intention to experiments with materials that don't nead cooling and ways of heat rescovering.
Same HP and 3 times the torque is inposible.
kW=Nm x RPM
This is the same for sterling, steam, diesel, otto, wankel, 1 shaft gasturbine, 2 shaft gasturbine, 3 shaft gas turbine and ac/dc motors. This formula is the same for anny engine design. kW=kNm/s=kJ/s You can argue this all you want, but it's a fact that will not go away. Go to a tecnical high school and ask about the realationship betwen RPM,kW and Nm, but you will probartly say the guys there have no clue what they are talking about.
You don't acept the conserns I have about boxers, but you make up your own as a exhuse for it not to be the leading design(do you think revetec is going to remove those conserns you came up with yourself?)
The gas turbine is advanced and the first one was buildt in 1906. The Napier deltic was advanced and build in the 40's. What is so special with the revetec that made it inpoible until now when computers show up?
Otto and Rudolf was good enginers and so was sterling. He's engine is one of the moust efficiant, but it are to slow to speed up so sadly enough it can't be used for mutch.
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  #39  
Old 02-25-2006, 10:30 AM
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Quote:
Originally Posted by stian1979
Are you the designer of this pice of crap?
No, but I'm a realistic engineer who can see what they are trying to make better.
And a designer who can recognise others ideals and efforts.
Quote:
You try to defend something that annyone can see is a hopeless idea.
No I try to defend someones idea from people who havent' thought it through and seem to know little about the engineering
Quote:
Do you know how mutch is lost in a engine because of friction?
yes. do you ?
Quote:
It's nothing compared to what you loss in heat radiation, coolong water and heat trough exhaust. It's a none exsisting problem.
oops, clearly NOT
Quote:
If someone want's seriosly to make some diferense they would put there intention to experiments with materials that don't nead cooling and ways of heat rescovering.
Correct and there are other engineers out there doing that too.
Is an improvement only to be considered if it makes EVERYTHING better ?

As I have pointed out what they are mainly concerning themselves with are the losses that offset crank in a normal engine causes. It's IS significant and when you tune an engine up becomes THE most common cause of engine failure
Quote:
Same HP and 3 times the torque is inposible.
It all depends where the HP is measured. Peak or at the same point on the torque curve.
Quote:
kW=Nm x RPM
This is the same for sterling, steam, diesel, otto, wankel, 1 shaft gasturbine, 2 shaft gasturbine, 3 shaft gas turbine and ac/dc motors. This formula is the same for anny engine design. kW=kNm/s=kJ/s You can argue this all you want, but it's a fact that will not go away. Go to a tecnical high school and ask about the realationship betwen RPM,kW and Nm, but you will probartly say the guys there have no clue what they are talking about.
wow, I and WHAT happened to LOSSES in your ideal model of the world ?
THAT is what was pointed out to you> You've got 1/10th of the information about an engine and implying far too much from it
Quote:
You don't acept the conserns I have about boxers, but you make up your own as a exhuse for it not to be the leading design
Sorry, I have responded to every one of your concerns with Boxer and refuted some of them> Liek the F1 nonsense and the "they all fail" rubbish. Don't confuse that with not also recognising their REAL problems ( and it's NOT oval cylinders because of gravity : ! ROFL )
[quote](do you think revetec is going to remove those conserns you came up with yourself?)[/quote}
I doubt Revetec will remove the problems a boxer inherently has.
BUT that doens't mean they can't make a more efficient "boxer" and where boxer engines HAVE proven themselves that they may be better !!
Do I think as Revetec could ever be a racing engine ? No I doubt it, but that's not what they're setting out to do
Quote:
The gas turbine is advanced and the first one was buildt in 1906. The Napier deltic was advanced and build in the 40's. What is so special with the revetec that made it inpoible until now when computers show up?
The abacus was the first hand held computer and designed thousands of years ago ... does that mean laptops and PDAs arne't "special" ? You're argument is non-sensical.
"advanced" for their day is the key terms. You'er getting all mixed up now
Quote:
Otto and Rudolf was good enginers and so was sterling. He's engine is one of the moust efficiant, but it are to slow to speed up so sadly enough it can't be used for mutch.
So what ? ( btw it's StIrling - A fellow Scot )
At least you NOW recognise that there are many designers and who knows in 10 years someone may hold the Revetec up as an important evolution and maybe they'll say that it can't be used for much> Does that remove from the engine objectives ? No. But you seem to be working hard selecting information shared to try to avoid that the Revetec is offering something different and MAY be better and has at least got ONE MAJOR company interested enough to think about production. ( That's more than Da Vinci managed with HIS engine )
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Old 02-25-2006, 10:43 AM
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I've moved all this here to save the annoyance of those interested in F1
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Old 02-25-2006, 01:23 PM
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unlike matra i do not feel a moral obligation to help the stuborn and stupid people of this world ...
so here's my reply ... " You sir are an idiot."
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Old 02-25-2006, 02:11 PM
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I actually like the Revetec concept as it is a new way of getting work out of the reciprocating piston. It certainly has some advantages going for it but well...

It didn't take me long to figure out a way for the revetec engine to work in a inline configuration. The solution I found also meant that they could run an even number of firings per revolution and I would suggest 2 (as in a 2 lobed cam) as this would allow better output speeds and slightly better effciency over a wider range of speeds.

Also it strikes me as odd that nobody has mentioned the most novel part of this system. The fact that the crank assembly translates the linier motion of the piston into rotary motion of the output at peak efficiency faster than a normal crankshaft, making better use of the higher pressure gasses in the chamber. To some of the critics: the 2.9x more torque you keep quoting is actually taken from a comparision between a single firing in a revetec versus a normal engine! the graph for the results is on the website somewhere...


oh and there are engines (mostly rotary) that show pretty large gains in efficiency over the humble piston engine (which has many fundamental flaws) I believe the Quasiturbine a proud canadian invention shows much better innovation and promise.
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Last edited by hightower99; 02-25-2006 at 02:30 PM.
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Old 02-25-2006, 03:05 PM
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Matra et Alpine Matra et Alpine is offline
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I had tried to point it out to him "ht", but as you see failed
Yeah the Q is another one of the interesting ones around.
I was concerned that it would suffer as the Wankel does of trying to maintain a good cylinder seal. Not seen any protoypes yet.
Btw "French-Canadian" --- so there will be HALF of a flaw in it
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Old 02-25-2006, 03:15 PM
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First sealing is no longer an issue for rotary engine like the wankel or Q they figured out what to make them of (aluminium-carbon alloy) and second check out the site (it is in english too!) and you can see a few prototypes...

And I know that it is French canadian and unfortunately I do not fit the stereotypical "I hate Quebec" mindset. I see Quebec as having some of the brightest minds on the planet...
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Old 02-25-2006, 03:50 PM
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Matra et Alpine Matra et Alpine is offline
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Quote:
Originally Posted by hightower99
First sealing is no longer an issue for rotary engine like the wankel or Q they figured out what to make them of (aluminium-carbon alloy)
Not sufficient to prevetn some bypass and limiting it's anti-pollution capability.
Quote:
and second check out the site (it is in english too!) and you can see a few prototypes...
From what I can see the only working ones they are showing are still teh air powered ones. It's takign AGES to try to go throught the numerous vids they seem to have in the hope of one having a detonation engine. Do you have a link to IT ?
PS: j'ai les voitures francaises. J'ai du apprendre comment lire et parler le francais
Quote:
And I know that it is French canadian and unfortunately I do not fit the stereotypical "I hate Quebec" mindset. I see Quebec as having some of the brightest minds on the planet...
I flew from Ottowa to Calgary once when the in-flight attendant started to repeat in French a guy three rows back shouted out we didnt' need that kind of talk now that we were in Alberta !! The ONLY time I ever saw it surface
( Sorry long-standing joke, the French will always have some fatal flaw that undermines the pure perfection )
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Last edited by Matra et Alpine; 02-25-2006 at 03:53 PM.
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