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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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."
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.
[IMG]http://www.quasiturbine.com/QTImages/QTWiki180px.jpg[/IMG]
I had tried to point it out to him "ht", but as you see failed :D
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 :D
[IMG]http://quasiturbine.promci.qc.ca/QTImages/QTSCExc578AnimNet.gif[/IMG]
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...
[quote=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) [/quote]
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...[/quote]
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...[/quote]
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 :D
( Sorry long-standing joke, the French will always have some fatal flaw that undermines the pure perfection :( )
The rigid reciprocating piston assembly is not balanced. Sure, the cams are balanced (they would be even if they weren't counter-rotating), but so is a crankshaft. The pistons in a conventional horizontally opposed engine move opposite each other to balance themselves. There are still third order movements, but they are minor. This Revetec engine design is a vibrating mess. Just watch the videos. Anything not rigidly connected to the stand buzzes like crazy whenever the engine is revved.
The rigid reciprocating piston assembly is heavy. All the reciprocating weight from a conventional engine (pistons & connecting rods) are maintained, but in place of lightweight pins we have heavy roller wheels and bearings. At least, they must be pretty heavy in order to transfer combustive force from the piston assembly to the cams. Also, roller wheels, even with strong bearings are subjected to metal-to-metal contact, and will wear accordingly. In comparison, conventional oilled bearing races are lightweight and extremely durable.
The twin counter-rotating cams push back on the pistons just as much as the pistons push on them (according to basic highschool Newtonian physics). This means that the cam follower on one side is pushed hard in the up direction as it follows the top of one cam lobe, while the follower on the opposite side (at the same piston end) is being pressed downward by the other cam lobe. This must result in some significant torque loading on the piston assembly. What's worse is that the direction of the torque load reverses for each and every stroke. I'm curious to know what provides the resistance to the torque loads.
They claim that a conventional engine doesn't acheive crank efficiency until 60deg ATDC. Maximum crank efficiency is where the crank is being pushed by the connecting rod at a tangent to it's travel. They provide some graphs:
.. but provide no information regarding how their device, which never pushes at a tangent to the travel of the cams, is any better. The graphs have no units and I don't see where the obvious mechanical disadvantage of the follower moving towards the axis (shorter lever arm = reduction in torque) is adequately portrayed by the vague green curve on their graph. At the time during the stroke when the piston pressure is the greatest, the piston has the most mechanical advantage, while it has the lowest mechanical advantage when it has the least piston pressure.
As in most engines, the ultimate limit to the rotational speed is the speed that the pistons travel. The folks at Revetec would like to remind you that by altering the cam profile, the maximum speed of the piston can be customized. What they don't tell you is that by altering the rod:stroke ratio and the stroke of a conventional engine will yeild the same changes in engine speed.
If you watch the video where they claim high revs, you can clearly see and hear that the engine is not revving very high. Why is this? Well, in order to get 3 strokes within one revolution, the engine will need to turn at about 1/3rd the speed of a similarly sized conventional engine (assuming both are limited by the maximum piston speed). You may get 3 times the amount of torque out of the Revetec, but you're only doing it with 1/3rd of the powerband... which brings me up to my last niggle:
I hope you're still reading, because this is a riot...
Revetec lists a portion of the articleTorque and Horsepower - A Primer on their website (CCE Design>>Let's Torque) which reads as follows:
Quote:
The Case For Torque
Now, what does all this mean in carland?
First of all, from a driver's perspective, torque, to use the vernacular, RULES :-). Any given car, in any given gear, will accelerate at a rate that *exactly* matches its torque curve (allowing for increased air and rolling resistance as speeds climb). Another way of saying this is that a car will accelerate hardest at its torque peak in any given gear, and will not accelerate as hard below that peak, or above it. Torque is the only thing that a driver feels, and horsepower is just sort of an esoteric measurement in that context. 300 foot pounds of torque will accelerate you just as hard at 2000 rpm as it would if you were making that torque at 4000 rpm in the same gear, yet, per the formula, the horsepower would be *double* at 4000 rpm. Therefore, horsepower isn't particularly meaningful from a driver's perspective, and the two numbers only get friendly at 5252 rpm, where horsepower and torque always come out the same.
In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm, especially when torque values are also climbing. Horsepower will continue to climb, however, until well past the torque peak, and will continue to rise as engine speed climbs, until the torque curve really begins to plummet, faster than engine rpm is rising. However, as I said, horsepower has nothing to do with what a driver *feels*.
You don't believe all this?
Fine. Take your non turbo car (turbo lag muddles the results) to its torque peak in first gear, and punch it. Notice the belt in the back? Now take it to the power peak, and punch it. Notice that the belt in the back is a bit weaker? Fine.
Wow, great! Torque is king! Power is meaningless!
Well, not really. If you read the article in full, you'll see that just the opposite is true.. only that Revetec would like you stop reading there. I wonder why Revetec doesn't want you know the entire story???
The next article (Why is Torque More Important than Horsepower?)refers to how engines with a lower state of tune are better for daily driving. This is true, we all like low end torque for leaving stoplights behind. What Revetec doesn't remind you is that their engine, spinning at 2000rpm is equivalent to your conventional engine spinning 6000rpm. Even though the output shaft is only spinning at 1/3rd the speed, the pistons are still screaming.
I don't see any real-life advantages to this Revetec engine over a conventional crank driven engine, and as long as Revetec isn't willing to provide any real life data they shouldn't be expecting me (or anyone else) to take stock in their company.
KnifeEdge_2K1 If you are so smart and I'm so stupid why am I the only one that ask questions about this SUPER design? It was something else once many years ago that was suposed to replace all engines in the world. What was the name again? hhmmmmmmmmmmmm think it started with a w and I think some asian car brand still use it in a model or two vx5 sa3 or rx7 some thing like that.
kW=kNm/s has nothing with no loss to do.
If the teoretical torque is 100Nm then the teoretical kW is 100Nm x RPM
If the real torque is 98Nm then the real kW is 98Nm x RPM
If you have 3 times the torque and the same hp it means you have mesured the engines under conditions that can not becompared or you runn designs of top and cylinder that can not be compared. If you runn same bore:stroke ratio and use same design of valves top and manifoil. Seams like you guys claim to be engineers and I am a engineer so I expect you to understand this mutch.
Well how mutch is the loss in bearings? annybody know?
[QUOTE=Matra et Alpine]Not sufficient to prevetn some bypass and limiting it's anti-pollution capability.[/QUOTE]
this is not true at all look at the results of the new RX 8 engine and you will see slightly less bypass then a comparable piston motor and that it is quite green. (low pollution without much more than a catalytic converter with an O2 sensor.)
[QUOTE=Matra et Alpine]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 ?[/QUOTE]
There is a movie on the website that is an episode from a french discovery channel and there you see Gilles the inventor starting a IC version of the Q he also cools it off in another seen by dumping some water over it while it is still running! unforunately I do not have a link.
[QUOTE=Matra et Alpine]j'ai les voitures francaises. J'ai du apprendre comment lire et parler le francais[/QUOTE] so you like renaults and Puegeots? and congradulations with being able to read and speak and write french!
Right on to the main attraction:
[QUOTE=stian1979]The rigid reciprocating piston assembly is not balanced.[/QUOTE] Yes it is balanced but the way it moves will create vibration.
[QUOTE=stian1979]Sure, the cams are balanced (they would be even if they weren't counter-rotating), but so is a crankshaft.[/QUOTE] first a normal crankshaft is not balanced when it is rotated by its self, it is considered close to being balanced when it has the whole weight of pistons and con-rods and all that. Second the counter rotating bit is not for balance it is to cancel Torqueing of the entire engine when reved! this alone is an improvement and worth about 3 points of overall drive train efficiency!
[QUOTE=stian1979]The pistons in a conventional horizontally opposed engine move opposite each other to balance themselves. There are still third order movements, but they are minor. This Revetec engine design is a vibrating mess.[/QUOTE] Boxer engines are one of the few configurations that can be perfectly balanced and the revetec does not gain this advantage due to both pistons being rigidly attached and moving as a whole in the same direction every stroke. However this issue is corrected in my design change!
[QUOTE=stian1979]The rigid reciprocating piston assembly is heavy. All the reciprocating weight from a conventional engine (pistons & connecting rods) are maintained, but in place of lightweight pins we have heavy roller wheels and bearings. At least, they must be pretty heavy in order to transfer combustive force from the piston assembly to the cams. Also, roller wheels, even with strong bearings are subjected to metal-to-metal contact, and will wear accordingly. In comparison, conventional oilled bearing races are lightweight and extremely durable.[/QUOTE] first their is a weight saving if you compare a set of pistons with a set of revetec ones. The weight is saved in the connecting rods that hold the two pistons together because they do not have to be as robust as normal connecting rods. also the pistons can be lighter because they don't need such large skirts to deal with side loading and since when did the bearings have to be "heavy" from your information you can only put forth that they most be tough and solid not heavy! with the roller contact the metal to metal contact occures between two surfaces the are moving in the same direction constantly they will not wera down any faster than any other bearing surface in an engine.
[QUOTE=stian1979]The twin counter-rotating cams push back on the pistons just as much as the pistons push on them (according to basic highschool Newtonian physics). This means that the cam follower on one side is pushed hard in the up direction as it follows the top of one cam lobe, while the follower on the opposite side (at the same piston end) is being pressed downward by the other cam lobe. This must result in some significant torque loading on the piston assembly. What's worse is that the direction of the torque load reverses for each and every stroke. I'm curious to know what provides the resistance to the torque loads.[/QUOTE] well just look at the engine the pistons are tied together and they are torqued in opposite directions therefore cancelling any vibration. This is also fixed in my design which has 3 lighter 2 lobe counter rotating cams instead of 2 heavier 3 lobed cams.
[QUOTE=stian1979]They claim that a conventional engine doesn't acheive crank efficiency until 60deg ATDC. Maximum crank efficiency is where the crank is being pushed by the connecting rod at a tangent to it's travel. They provide some graphs:[/QUOTE] Actually they claim that a normal piston makes peak torque (a combination of high cylinder pressure and high coversion) at 60deg ATDC this is generally true.
[QUOTE=stian1979].. but provide no information regarding how their device, which [B]never pushes at a tangent to the travel of the cams[/B], is any better. The graphs have no units and I don't see where the obvious mechanical disadvantage of the follower moving towards the axis (shorter lever arm = reduction in torque) is adequately portrayed by the vague green curve on their graph. At the time during the stroke when the piston pressure is the greatest, the piston has the most mechanical advantage, while it has the lowest mechanical advantage when it has the least piston pressure.
As in most engines, the ultimate limit to the rotational speed is the speed that the pistons travel.[/QUOTE]
You obviously haven't looked at this engine have you. The whole advantage of the revetec is that it almost immediately after combustion starts the piston is pushing the cams at a tangent making much more torque. You are however correct in pointing out that the point at which the piston pushes the cam has less and less of a lever as the power stroke goes on. Pressure in the cylinder is greatest close at TDC and alittle after that it starts dropping very quickly, in normal piston engines the high mechanical efficiency is achieved when there is very low cylinder pressure and when there is high cylinder pressure the normal crankshaft is pathetic at making anything of it! well has anybody noticed that the novelty in the revetec engine is that you only need 1/3 the stroke and can therefore attain higher output speeds! The bore:stroke ratio in a revetec shoud be something close to F1 (large bore, short stroke) this allows more area for the valves for better breathing and higher output speeds.
[QUOTE=stian1979]If you watch the video where they claim high revs, you can clearly see and hear that the engine is not revving very high. Why is this? Well, in order to get 3 strokes within one revolution, the engine will need to turn at about 1/3rd the speed of a similarly sized conventional engine (assuming both are limited by the maximum piston speed). You may get 3 times the amount of torque out of the Revetec, but you're only doing it with 1/3rd of the powerband... which brings me up to my last niggle:[/QUOTE] hmm this is an odd statement. You can hear that the engine is running slowly? (if both the revetec and a normal engine have the same max piston speed then the only thing running at a different speed is the crankshaft, and I don't think you are claiming that you can hear if the crankshaft is turning faster or slower are you?) You are misunderstanding something here I think you meant to say that the revetec gets 3 times more torque but at 1/3 the output speed. this is not true the revetec only claimed that they get 2.9 times more toque per firing not per engine speed!
Hmm that artical you posted was made not by revetec but by someone else trying to market it or something. I agree that it is full of Shite but don't let one misguided soul ruin everything!
BTW has nobody figured out that HP is TorqueXRPM where as Torque is a stationary measure of force? HP is what moves the car!
[QUOTE=stian1979]KnifeEdge_2K1 If you are so smart and I'm so stupid why am I the only one that ask questions about this SUPER design? It was something else once many years ago that was suposed to replace all engines in the world. What was the name again? hhmmmmmmmmmmmm think it started with a w and I think some asian car brand still use it in a model or two vx5 sa3 or rx7 some thing like that.[/QUOTE] hmmm do you mean the sublime wankel motor in the new RX8? well you shouldn't make fun it has the highest HP/cc of any production naturally aspirated engine it isn't the designs fault that only Mazda had the balls to see the R&D through!
[quote=hightower99]this is not true at all look at the results of the new RX 8 engine and you will see slightly less bypass then a comparable piston motor and that it is quite green. (low pollution without much more than a catalytic converter with an O2 sensor.)[/quote]
In the UK the Renesis engine is producing 20% MORE emissions and 10% LESS mileage than say the Honda S2000.
it also uses oil, so it would suggest that PART of the improvement in the tip is sacrificial oiling, but the owner at Knockhilll didnt' know much technical stuff :(
[quote]There is a movie on the website that is an episode from a french discovery channe[/quote]
damn, every time I tried to get that one it was freezing half way through :(
Further evidence of Murphy's law.
Cheers I'll try anotehr route to get it.
[quote]so you like renaults and Puegeots? and congradulations with being able to read and speak and write french![/quote]
Alpines and Matras really :) ( Hence the nic ) My French isnt' good enough when trying to explain a problem in a 25 year old Matra to a French garage owner who is expert on the car but speaks no English !!!! THe A610 is even better(!) as the German tuner speaks no Egnlish, but one of his mechanics speaks French, so we have had some 3-way conversations in a mixture of German ( I understand a little ) and French !!!!!
[quote]hmmm do you mean the sublime wankel motor in the new RX8? well you shouldn't make fun it has the highest HP/cc of any production naturally aspirated engine it isn't the designs fault that only Mazda had the balls to see the R&D through![/quote]
Definately. Maybe, it was always doomed because of the "equivalence formula" applied to it. After the successes of the Le Mans cars it would have been nice to see it entered in different formulas. So it is those who like "quirky" and "different" who will look at it and enjoy it's smooth revving. When the RX-8 race series was running it was like listening to a bike grid :D
[QUOTE=stian1979]The rigid reciprocating piston assembly is not balanced. Sure, the cams are balanced (they would be even if they weren't counter-rotating), but so is a crankshaft. The pistons in a conventional horizontally opposed engine move opposite each other to balance themselves. There are still third order movements, but they are minor. This Revetec engine design is a vibrating mess. Just watch the videos. Anything not rigidly connected to the stand buzzes like crazy whenever the engine is revved.
The rigid reciprocating piston assembly is heavy. All the reciprocating weight from a conventional engine (pistons & connecting rods) are maintained, but in place of lightweight pins we have heavy roller wheels and bearings. At least, they must be pretty heavy in order to transfer combustive force from the piston assembly to the cams. Also, roller wheels, even with strong bearings are subjected to metal-to-metal contact, and will wear accordingly. In comparison, conventional oilled bearing races are lightweight and extremely durable.
The twin counter-rotating cams push back on the pistons just as much as the pistons push on them (according to basic highschool Newtonian physics). This means that the cam follower on one side is pushed hard in the up direction as it follows the top of one cam lobe, while the follower on the opposite side (at the same piston end) is being pressed downward by the other cam lobe. This must result in some significant torque loading on the piston assembly. What's worse is that the direction of the torque load reverses for each and every stroke. I'm curious to know what provides the resistance to the torque loads.
They claim that a conventional engine doesn't acheive crank efficiency until 60deg ATDC. Maximum crank efficiency is where the crank is being pushed by the connecting rod at a tangent to it's travel. They provide some graphs:
.. but provide no information regarding how their device, which never pushes at a tangent to the travel of the cams, is any better. The graphs have no units and I don't see where the obvious mechanical disadvantage of the follower moving towards the axis (shorter lever arm = reduction in torque) is adequately portrayed by the vague green curve on their graph. At the time during the stroke when the piston pressure is the greatest, the piston has the most mechanical advantage, while it has the lowest mechanical advantage when it has the least piston pressure.
As in most engines, the ultimate limit to the rotational speed is the speed that the pistons travel. The folks at Revetec would like to remind you that by altering the cam profile, the maximum speed of the piston can be customized. What they don't tell you is that by altering the rod:stroke ratio and the stroke of a conventional engine will yeild the same changes in engine speed.
If you watch the video where they claim high revs, you can clearly see and hear that the engine is not revving very high. Why is this? Well, in order to get 3 strokes within one revolution, the engine will need to turn at about 1/3rd the speed of a similarly sized conventional engine (assuming both are limited by the maximum piston speed). You may get 3 times the amount of torque out of the Revetec, but you're only doing it with 1/3rd of the powerband... which brings me up to my last niggle:
I hope you're still reading, because this is a riot...
Revetec lists a portion of the articleTorque and Horsepower - A Primer on their website (CCE Design>>Let's Torque) which reads as follows:
Quote:
The Case For Torque
Now, what does all this mean in carland?
First of all, from a driver's perspective, torque, to use the vernacular, RULES :-). Any given car, in any given gear, will accelerate at a rate that *exactly* matches its torque curve (allowing for increased air and rolling resistance as speeds climb). Another way of saying this is that a car will accelerate hardest at its torque peak in any given gear, and will not accelerate as hard below that peak, or above it. Torque is the only thing that a driver feels, and horsepower is just sort of an esoteric measurement in that context. 300 foot pounds of torque will accelerate you just as hard at 2000 rpm as it would if you were making that torque at 4000 rpm in the same gear, yet, per the formula, the horsepower would be *double* at 4000 rpm. Therefore, horsepower isn't particularly meaningful from a driver's perspective, and the two numbers only get friendly at 5252 rpm, where horsepower and torque always come out the same.
In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm, especially when torque values are also climbing. Horsepower will continue to climb, however, until well past the torque peak, and will continue to rise as engine speed climbs, until the torque curve really begins to plummet, faster than engine rpm is rising. However, as I said, horsepower has nothing to do with what a driver *feels*.
You don't believe all this?
Fine. Take your non turbo car (turbo lag muddles the results) to its torque peak in first gear, and punch it. Notice the belt in the back? Now take it to the power peak, and punch it. Notice that the belt in the back is a bit weaker? Fine.
Wow, great! Torque is king! Power is meaningless!
Well, not really. If you read the article in full, you'll see that just the opposite is true.. only that Revetec would like you stop reading there. I wonder why Revetec doesn't want you know the entire story???
The next article (Why is Torque More Important than Horsepower?)refers to how engines with a lower state of tune are better for daily driving. This is true, we all like low end torque for leaving stoplights behind. What Revetec doesn't remind you is that their engine, spinning at 2000rpm is equivalent to your conventional engine spinning 6000rpm. Even though the output shaft is only spinning at 1/3rd the speed, the pistons are still screaming.
I don't see any real-life advantages to this Revetec engine over a conventional crank driven engine, and as long as Revetec isn't willing to provide any real life data they shouldn't be expecting me (or anyone else) to take stock in their company.
KnifeEdge_2K1 If you are so smart and I'm so stupid why am I the only one that ask questions about this SUPER design? It was something else once many years ago that was suposed to replace all engines in the world. What was the name again? hhmmmmmmmmmmmm think it started with a w and I think some asian car brand still use it in a model or two vx5 sa3 or rx7 some thing like that.
kW=kNm/s has nothing with no loss to do.
If the teoretical torque is 100Nm then the teoretical kW is 100Nm x RPM
If the real torque is 98Nm then the real kW is 98Nm x RPM
If you have 3 times the torque and the same hp it means you have mesured the engines under conditions that can not becompared or you runn designs of top and cylinder that can not be compared. If you runn same bore:stroke ratio and use same design of valves top and manifoil. Seams like you guys claim to be engineers and I am a engineer so I expect you to understand this mutch.
Well how mutch is the loss in bearings? annybody know?[/QUOTE]
torque is what determines how fast u accelerate at any given point but ur also forgetting torque at the wheels is what matters and that changes with the gear ratios, power is what ultimately determines speed when all other factors are fixed
you can beef up the torque band and NOT significantly affect the max power
you cant really use the same formula for torque x rpm = power since the revtec engine fires 3 times per revolution of the crank and not 1 per 2 revolution of the crank like a regular piston engine (this is per cylinder)
the revtec is firing 6 times as much as a regular piston engine in the same amount of time
the rev limit on an engine is not determined by how fast the piston moves, its how much stress the conrods can take at the speed the piston moves, its a subtle but important difference, there are no conrods in the revtec engine so the max rpm must be limited by another factor
there so much more thats wrong with what u said i just dont have any time to argue wit hu
M=F x l
If you got anny tecnical education I gues you know what this means.
As long as you have a konstand F you can not increase M without making l longer.
If you want 3 times the torque you have to make the diameter of the crank or whatever 3 times larger. This is unless you find a eficiant way of transfering the power to the crank so less energy escape trough the cooling system. but this would mean that they acheved 90% engine efficensy.
40% of the energy don't get used and escape trough the exhaust so this engine is feed with 130%?
It's too mutch things here that don't ad up.
[QUOTE=hightower99]
BTW has nobody figured out that HP is TorqueXRPM where as Torque is a stationary measure of force? HP is what moves the car![/QUOTE]
Exsactly
[QUOTE=hightower99]hmmm do you mean the sublime wankel motor in the new RX8? well you shouldn't make fun it has the highest HP/cc of any production naturally aspirated engine it isn't the designs fault that only Mazda had the balls to see the R&D through![/QUOTE]
I do not make funn of it, but for some time everyone thought it was suposed to end up in every car. It's not even with mazda.
[QUOTE=KnifeEdge_2K1]torque is what determines how fast u accelerate at any given point but ur also forgetting torque at the wheels is what matters and that changes with the gear ratios, power is what ultimately determines speed when all other factors are fixed
you can beef up the torque band and NOT significantly affect the max power
you cant really use the same formula for torque x rpm = power since the revtec engine fires 3 times per revolution of the crank and not 1 per 2 revolution of the crank like a regular piston engine (this is per cylinder)
the revtec is firing 6 times as much as a regular piston engine in the same amount of time
the rev limit on an engine is not determined by how fast the piston moves, its how much stress the conrods can take at the speed the piston moves, its a subtle but important difference, there are no conrods in the revtec engine so the max rpm must be limited by another factor
there so much more thats wrong with what u said i just dont have any time to argue wit hu[/QUOTE]
Piston speed is what sets the limits. If you want to go beond this limits you have to find a fuel that burn faster. If you look at low rpm engines and high rpm engines they got the same piston speed. You bether don't argue with me since you are only making a fool out of yourself.
[QUOTE=hightower99]
Boxer engines are one of the few configurations that can be perfectly balanced and the revetec does not gain this advantage due to both pistons being rigidly attached and moving as a whole in the same direction every stroke. However this issue is corrected in my design change!
[/QUOTE]
To stopp the vibration caused from the two pistions moving the same way they have to use balance shafts and then one of fatastic advantages is gone. It has the same counter weihts as a normal engine
The australians have this strange designs that is going to save the world, did annyone see the crankless engine? I would not call it that, but more like a aksial crank. All forces from the pistion is transfered trough a trust bearing.
To be honest I like the Sytec engine design bether.
[url]www.cmcpower.com[/url]
[quote=stian1979]To stopp the vibration caused from the two pistions moving the same way they have to use balance shafts and then one of fatastic advantages is gone. It has the same counter weihts as a normal engine[/quote]
THIS was covered before.
A boxer has OPPOSING pistons and so s self-balanced.
You are confusing a V180 configuration.
[quote]The australians have this strange designs that is going to save the world, did annyone see the crankless engine? I would not call it that, but more like a aksial crank. All forces from the pistion is transfered trough a trust bearing.[/quote]
There are quite a few different ideas coming out of Australia just now and Canada - must be all those immigrant Scots :D.
Of course you can go back to 1930 and Bourke's design -- whcih I see is being resurrected again :D
[quote]To be honest I like the Sytec engine design bether.
[URL="http://www.cmcpower.com"]www.cmcpower.com[/URL][/quote]Each have advantages/disadvatages. As long as you are as critical and honest :D
Me ? I would LOVE to see the Rand Cam engine work. Now THAT is thinking different :D 24 combustion events per rotation :D
As was said before, there are LOTS of clever an innovative designs coming out and being prototyped for full evaluation.
[QUOTE=stian1979]M=F x l
If you got anny tecnical education I gues you know what this means.
As long as you have a konstand F you can not increase M without making l longer.
If you want 3 times the torque you have to make the diameter of the crank or whatever 3 times larger. This is unless you find a eficiant way of transfering the power to the crank so less energy escape trough the cooling system. but this would mean that they acheved 90% engine efficensy.
40% of the energy don't get used and escape trough the exhaust so this engine is feed with 130%?
It's too mutch things here that don't ad up.
Piston speed is what sets the limits. If you want to go beond this limits you have to find a fuel that burn faster. If you look at low rpm engines and high rpm engines they got the same piston speed. You bether don't argue with me since you are only making a fool out of yourself.
[/QUOTE]
you do know that's the formula for work ... if the engine fires 3 times as much as a regular engine then it will produce 3 times the work at the same rpm
piston speed isnt determined by rpm alone, the stroke needs to be taken into account, thats why f1 engines can reach 19000 rpm
and its not the pistons that limit the rpm its the conrods, the piston isnt what's going to give first, thats the conrods, there are no conrods in the revtec engine
[QUOTE=Matra et Alpine]THIS was covered before.
A boxer has OPPOSING pistons and so s self-balanced.
You are confusing a V180 configuration.[/QUOTE]
Yes a boxer is self-balanced, but the revetec is not. the pistons here move the same way and are not moving against eatch other like a boxer. It neads balance shafts with counter weights.
[QUOTE=KnifeEdge_2K1]you do know that's the formula for work ... if the engine fires 3 times as much as a regular engine then it will produce 3 times the work at the same rpm[/QUOTE]
Yes so what is the magic of 2,9 times the torque when you nead 3 times the work cycles to perform it?
[QUOTE=KnifeEdge_2K1]piston speed isnt determined by rpm alone, the stroke needs to be taken into account, thats why f1 engines can reach 19000 rpm
and its not the pistons that limit the rpm its the conrods, the piston isnt what's going to give first, thats the conrods, there are no conrods in the revtec engine[/QUOTE]
Different explosesivs have diferent detonation speed, what fuel will you use to make the revetec spin at 19000rpm?
TNT has a detonation speed of 7,7km/s or was it nitroglyserin?
When F1 cars was reatching 14000RPM they got problems with valve flow.
This problem was solved by using praumatic springs.
Also they use short stroke/larger bore to get biger valve area per/ccm
You will come into alot of other problems in reatching higher pistionspeed than conroads.
If you look at a huge two stroke diesel with 90RPM and a smal cummins diesel with 2100RPM you will see the piston speed is about the same, 9m/s if I remember corectly.
F1 is a milion dollar industry, if conrods was a problem for RPM torque and horcepower they would find a sulution a long time ago.
If you blow a gasket in the top, how long will those conection pins last? will they just snap and the pistion go straight trough the top?
[QUOTE=stian1979]Yes a boxer is self-balanced, but the revetec is not. the pistons here move the same way and are not moving against eatch other like a boxer. It neads balance shafts with counter weights.
Yes so what is the magic of 2,9 times the torque when you nead 3 times the work cycles to perform it?
Different explosesivs have diferent detonation speed, what fuel will you use to make the revetec spin at 19000rpm?
TNT has a detonation speed of 7,7km/s ot was it nitroglyserin?
When F1 cars was reatching 14000RPM they got problems with valve flow.
This problem was solved by using praumatic springs.
Also they use short stroke to get biger valve area per/ccm
You will come into alot of other problems in reatching higher pistionspeed than conroads.
F1 is a milion dollar industry, if conrods was a problem for RPM torque and horcepower they would find a sulution a long time ago.
If you blow a gasket in the top, how long will those conection pins last? will they just snap and the pistion go straight trough the top?[/QUOTE]
i never said the revtec could reach 19000 rpm tho, im just using f1 engines as an example because they run on pump ... well nearly pump gas as well
yeah they get problems with the valves but thats cuz they dont rebound as fast and "jump" is the term if iirc, the detonation speed of the fuel isnt the limiting factor
but actually after you brought up those points im beginning to see ur side of the argument, never thought about it that way, since it is producing 3 times the torque at 1/3rd the rpm with 3 times the number of detonations per unit time ... doesnt seem to be so amazing no more ... :(
There is alot of things out there.
New ways of transfering work from combustion to rotation.
[url]www.revetec.com[/url]
[url]www.quasiturbine.com[/url]
[url]www.cmcpower.com[/url] (I kind of like this one myself even it has the balance problem)
[url]www.splitcycle.com.au[/url]
Some guys trying to make V configuration with Scotch Yoke cycle [url]www.sliderengine.com[/url]
New top and valve designs.
[url]www.jack-brabham-engines.com[/url]
[url]www.coatesengine.com/index.html[/url]
[url]www.rcvengines.com[/url]
[url]www.new4stroke.com[/url]
Thanks Matra et Alpine I have totaly forgoten about the rand cam.
I was looking at it some years ago.
[url]www.regtech.com[/url]
and then the MYT engine that I stil don't quite understand, but there must be some gears that prevent the pistions to return so will that be a problem for reabilety?
[url]www.plug2work.com/angellabsllc/index.html[/url]
This one is simpe
[url]www.archerengine.dabsol.co.uk/detail.htm[/url]
What is up with the australians and crankshafts?
The all mighty australian crank less engine (aksial crank I would call it)
[IMG]http://i43.photobucket.com/albums/e353/stian1979/bxtai0489t.jpg[/IMG]
[IMG]http://i43.photobucket.com/albums/e353/stian1979/crankless-figure.jpg[/IMG]
[IMG]http://i43.photobucket.com/albums/e353/stian1979/crankless80cm.jpg[/IMG]
I know what you mean. I newer like the layout, but I was impresed about the torque until those same facts was put into my mind by a arguement.
I was born in hospital and driven home in a Otto driven car and I do belive the basic same layout will drive me to the grave. I think maybe more complex and exspensive systems like compund engines and turbos to recover heat loss and more ceramicswitch to prevent heat loss will be adopted. This is the main problems the combustion engine and when oil become so exspensive that consumors are willing to pay for the tecnology it will probartly hapend.
Maybe I'm wrong and I have ben convinced manny times that I am, but In the end I go back to my orginal opinion.
[quote=stian1979]What is up with the australians and crankshafts?
The all mighty australian crank less engine (aksial crank I would call it)[/quote]
It's words that rhyme with wank that cause them problems.
It goes back to childhood and being caught at it :D
[quote]Maybe I'm wrong and I have ben convinced manny times that I am, but In the end I go back to my orginal opinion.[/quote]
The list was the only point I was trying to make at the start. There are lots of good ideas begng tested to see if they bring a discernible benefit. The prototypes are the only way to ultimately prove/disprove if the increase is achieved in the real world. The markets will decide :D
PS: Good chance you'll get driven there in an electric hybrid, so only half an Otto :D
PPS: Quick patent idea. Use the energy from combustion of the human body to drive a Stirling engine. Load your body in at your home and deliver the ashes at the internment. Zero energy cremations :) Thin people have to be interned close to home :D
Stirling engine has a limited use since it can't take quick changes in load.
Electric hybrids is something I don't belive in it's more about what the green consumer want to buy. More weight to pull around and you have loss in electric generator and engines. I got more belife in a engine running at constant rpm and a CVT gearbox.
Stirling hybrid could be interestin. A convensional combustion engine taking care of aceleration and a stirling to recover heat. When the heat transfere to the stirling has made it take load the combustion engine will deload. Replace the traditional radiator by a stirling.
Lot's of things still not tryed just waiting for someone to fail or rice to glory.
One thing I'm shure of is that transfering the liniar motion into rotary the development is allready don 100 times in the past and we would come a long way if those guys around used there energy on heat recovery instead of solving problems that don't eksists.
[quote=stian1979]Stirling engine has a limited use since it can't take quick changes in load. [/quote]
The point is you would use a Stirling to generate electrical power and use an electric motor to provide htre driven poiwer. The high efficiency possibly with Stirlings amkes it not as inefficient as with ICEs. Why woudl ANYOEN think to use a Stirling direct drive ??? it takes a HUGE piston to generate enought torque to be usable !!!!
[quote]Electric hybrids is something I don't belive in it's more about what the green consumer want to buy. More weight to pull around and you have loss in electric generator and engines. I got more belife in a engine running at constant rpm and a CVT gearbox.[/quote]
With in-wheel motors you save significant mechanical losses that make up for the weight ( which is coming down each year ).
CVTs are very innefficient for heavy vehicles as they require high forces to prevent slip :( High forces then gives higher frictional losses.
[quote]Stirling hybrid could be interestin. A convensional combustion engine taking care of aceleration and a stirling to recover heat. When the heat transfere to the stirling has made it take load the combustion engine will deload. Replace the traditional radiator by a stirling.[/quote]
You'd be more efficient just providng a high efficiency burner heating the heat end of the Stirling. Burners can get 98% efficient an ICE to generate the heat by scavenging still can't get near the theoretical numbers of an efficient Stirling.
[quote]Lot's of things still not tryed just waiting for someone to fail or rice to glory.
One thing I'm shure of is that transfering the liniar motion into rotary the development is allready don 100 times in the past and we would come a long way if those guys around used there energy on heat recovery instead of solving problems that don't eksists.[/quote]
But you STILL keep ignoring the Rvetec solution to opposing piston issue :)
Let's try one last time to get you to understand it.
Linear balance is OK in an engine as you can readily balance that out. Cranks give vector forces and you still ignore those in your comparisons :D
So the linked piston of a Revetec or Bourke et al all are easily balanced as it only moves linearly. Trying to make a weight on rotating cranks plus linear motion piston balance out is what hurts "normal" engines :D
Draw the vector force diagrams for a crank and non-crank engine and you'll understand. A lot of work for gudgeon, conrod and crank for the full cycle but clearly you need to do it to grasp the other forces you're ignoring and minimising even though they are BIG issues in engines
So you are miossing the point when you say these things don't exist !!!
[QUOTE=Matra et Alpine]The point is you would use a Stirling to generate electrical power and use an electric motor to provide htre driven poiwer. The high efficiency possibly with Stirlings amkes it not as inefficient as with ICEs. Why woudl ANYOEN think to use a Stirling direct drive ??? it takes a HUGE piston to generate enought torque to be usable !!!!
With in-wheel motors you save significant mechanical losses that make up for the weight ( which is coming down each year ).
CVTs are very innefficient for heavy vehicles as they require high forces to prevent slip :( High forces then gives higher frictional losses.
You'd be more efficient just providng a high efficiency burner heating the heat end of the Stirling. Burners can get 98% efficient an ICE to generate the heat by scavenging still can't get near the theoretical numbers of an efficient Stirling.
But you STILL keep ignoring the Rvetec solution to opposing piston issue :)
Let's try one last time to get you to understand it.
Linear balance is OK in an engine as you can readily balance that out. Cranks give vector forces and you still ignore those in your comparisons :D
So the linked piston of a Revetec or Bourke et al all are easily balanced as it only moves linearly. Trying to make a weight on rotating cranks plus linear motion piston balance out is what hurts "normal" engines :D
Draw the vector force diagrams for a crank and non-crank engine and you'll understand. A lot of work for gudgeon, conrod and crank for the full cycle but clearly you need to do it to grasp the other forces you're ignoring and minimising even though they are BIG issues in engines
So you are miossing the point when you say these things don't exist !!![/QUOTE]
If you use a electric engine it will require more power when you acelerate.
To suply more power the load on the stirling has to increase and because of the stirlings slow response to load changing it would drop in speed (just read about diesel generator's and speed drop).
A battery package would prevent this, but ad extra weight.
Williams F1 made a CVT in 1994 to be used in racing, but CVT was baned when FIA found out what Sir Frank was up to, but the tecnology to make CVT handle 700Hp is out there.
Yes it's easy to balance it, but it require a balance shaft and this consume power and ads weight to the construction and I'm stil woried about the bearing.
And I don't belive they can put out more torque with the same cylinder preshure, bore and stroke. Let me explain this in a drawing
[IMG]http://i43.photobucket.com/albums/e353/stian1979/torqueandbearing.jpg[/IMG]
If I got to chose the engine design in my car I know what I would do.
It's a two stroke so It neads seperate cylinder lubrication yes, but it's just soo cool
[IMG]http://i43.photobucket.com/albums/e353/stian1979/Napier_deltic_animation.gif[/IMG]
And with compund where you can inject fuel into the exhast to get some extra hp out of the turbine when neaded
[IMG]http://i43.photobucket.com/albums/e353/stian1979/Napier_Nomad.jpg[/IMG]
The smal english companys really know how to make engines, to bad they are gone or close to.
[quote=stian1979]If you use a electric engine it will require more power when you acelerate.
To suply more power the load on the stirling has to increase and because of the stirlings slow response to load changing it would drop in speed (just read about diesel generator's and speed drop).
A battery package would prevent this, but ad extra weight.[/quote]
Correct, but if it is only required for short periods it does NOT as large a penalty. It's only needed for averaging the peak needs with the average output of a VERY efficient engine. I thought that was obvious :(
[quote]Williams F1 made a CVT in 1994 to be used in racing, but CVT was baned when FIA found out what Sir Frank was up to, but the technology to make CVT handle 700Hp is out there. [/quote]
Careful.
DAF had been racing the CVT in F3 ( with no great success with the layout ) - we've talked about it before on UCP with pics - and Frank worked with them to design a new one and TEST it. Whether it actually delivered any benefit for the weight and stresses was never published and the FIA banned it before it
DC test drove the one in '93
[IMG]http://8w.forix.com/altpower/williamscvt.jpg[/IMG]
The FIA banned CVT as they felt it took away from the driver. Not for technical reasons. So it never went any further. So we never knew whether it was able to handle the torque lash of kerbs corner on full throttle or if it lasted 2 hours.
Where did you find a reference to it actually HANDLING the 700HP for duration ???
[quote]Yes it's easy to balance it, but it require a balance shaft and this consume power and ads weight to the construction and I'm stil woried about the bearing.[/quote]
It's NOT easy to "balance" an engine. Even the best balancer shafts have recognised frequencies in the engine where they are ineffective due to harmonics.
But the Revetec doesn't' need contra-rotating balanceshafts as it isnt' trying to balance a ROTATING mass. You dint' seem to grasp the difference :)
[quote]And I don't belive they can put out more torque with the same cylinder preshure, bore and stroke. Let me explain this in a drawing[/quote]
By the time you get to the point in the curve you have used up ( or should have ) the expansion of the gasses - with a little left over to assist exhaust flow ). So you are mathematically correct if you were running an engine driven by compressed air. But you're not. You are running a COMBUSTION engine which has a peak pressure which drops as the piston recedes. As I said before, you seem to only see one thing at a time. Each thing on it's own is valid. BUT when you take the other factors into account aren't .
oh and your bearing PROVES you didnt' bother reading. It does NOT matter how long a bearing is it only matters how large the mating surface is. What is too difficult for you to grasp that ??
[quote]The smal english companys really know how to make engines, to bad they are gone or close to.[/quote]
They're not. There are plenty of companies producing new engines on a regular basis.
PS: 2-strokes can't clean up emissions without major post combustion management. You can't burn heavy lubricating oils without emission problems. Sadly nobody wants to invest in finding solutions.
[QUOTE=Matra et Alpine][quote=stian1979]If you use a electric engine it will require more power when you acelerate.
To suply more power the load on the stirling has to increase and because of the stirlings slow response to load changing it would drop in speed (just read about diesel generator's and speed drop).
A battery package would prevent this, but ad extra weight.[/quote}
Correct, btu if it is only required for short periods it does NOT as larege a penalty. It's only needed for averaging the peak needs withthe average output fo a VERY efficient engine. I thought that was obvious :(
Careful.
DAF had been racing the CVT inf F3 - we've talked abotu it before on UCP with pics - and Frank worked with them to TEST it. Whether it actually delevered any benefit for the weight and stresses was never published and the FIA banned it before it
DC test drove the one in '93
[IMG]http://8w.forix.com/altpower/williamscvt.jpg[/IMG]
The FIA banned CVT as they felt it took away from the driver. Not for technical reasons. So it never went any further. So we never knew whether it was able to handle the torque lash of kerbs corner on full throttle or if it lasted 2 hours.
Where did you find a reference to it actually HANDLING the 700HP for duration ???
It's NOT easy to "balance" an engine. Even the best balancer shafts have recognised frequencies in the engine where they are inneffective due to harmonics.
But the Revetec doesnt' need contra-rotating balanceshafts as it isnt' trying to balance a ROTATING mass. You dont' seem to grasp the difference :)
By the time you get to the point in the curve you have used up ( or should have ) the expansion of the gasses - with a little left over to assist exhaust flow ). So you are mathematically correct if you were running an engine driven by compressed air. But you're not. You are running a COMBUSTION engine which has a peak pressure which drops as the piston recedes. As I said before, you seem to only see one thing at a time. Each thing on it's own is valid. BUT when you take the other factors into account aren't .
They're not. THere are plenty of companies producing new engines on a regular basis.
PS: 2-strokes can't clean up emissions without major post combustion management. You can't burn heavy lubricating oils wihtout emission problems. Sadly nobody wants to invest in finding solutions.[/QUOTE]
DC put in some impresive lap times with the CVT in testing.
To acelerate a famely van it take some power so batterys had to have a size that would ad weight and take away space. A famely car of some size 1500kg from 0-100km/h in 11 secs nead some power and if you got batterys fully loaded and acelerate to 80km/h and a dude runn into the road so you got to brake. Then you step on it again and at 90km/h the car just die because batterys are runn empthy and the stirling stil did not get up too speed yet so you are limited to 50km/h and slovly acelerating until you reatch 100km/h.
I got more belif that it has to be combined with a traditional combustion engine. Maybe a combustion engine only enabled on city driving and aceleration, disabled during freeway. who konw.
So with out balance shafts, how will you make the forces from the pistons not to ad vibration? This is not a boxer in case you did not notice so both pistons move toward's the same side at the same time. If the engine was constructed without conrods just like the revetec is and at the same time was able to make pistons move towards eatch other like a boxer no balancing would be required. Since the crankshaft rotate 1 per 3 work cycles counter weights can not be added to this, some thing you see is obious so it will nead a balance shaft to balance out the oscilating movements from pistions. Rotating alancing is not a problem like the traditional conrods I can agree.
1/2 of the conrod is considered to be oscilating and the other 1/2 is considered to be rotating. I did my homework on this, probartly the only thing about engine dynamics I still remember.
2-strokes are the moust inviromental engines. You don't find anny engine more fuel efficiant than sulzer or B&W 2-strokes. consumtion of cylinder lube oil is a problem caused by the fact that no syntetic oil is made for this purpose. No ship owner want to buy syntetic oil for this purpose since it will cost him soo mutch that he's compatitors will get the contracts.
About cylinder preshure I'm right. Even the preshure drops by 50% I will stil have 50% longer arm than the revetec. It all ends up in the same in the end. The only advantage by geting long arm at a earlier stage is that not that mutch energy has escaped trough the top and cylinderwals yet, but this problem is smal and will be solved at once the customers are willing to pay for cheramic and insolated engines due to fuel prices. There is no practical reason for adapting this design. I like it, it's a funn concept, but it's also all it is.
I'm stil concerned about the bearing. Not anny ball bearing is 100% round, maybe it is 99,9999999%, but not 100% ball barings don't handle the same load as a plain baring and if anny contamination in the oil like soot or other particles it will just dig into the plain bearing and do no futher harm.
A ballbearing can more easely get permanent problems witch I'm shure you are avear off.
[quote=stian1979][quote=Matra et Alpine]
DC put in some impresive lap times with the CVT in testing.[/quote]
You got any actual figures.
All that I remember about it was platitudes.
ANd nobody says theire idea is a dog :)
[quote]To acelerate a famely van it take some power so batterys had to have a size that would ad weight and take away space. A famely car of some size 1500kg from 0-100km/h in 11 secs nead some power and if you got batterys fully loaded and acelerate to 80km/h and a dude runn into the road so you got to brake. Then you step on it again and at 90km/h the car just die because batterys are runn empthy and the stirling stil did not get up too speed yet so you are limited to 50km/h and slovly acelerating until you reatch 100km/h. [/quote]
You are AGAIN thinking of only one issue at a time>
The problem is only when you first start up. AS SAID, you would size the battery to manage the peak. You dont' accelerate a car for 20 seconds :D
Sorry but you're missing the whole point by being single-thinking. Build in what the Stirling engien is doing durign the acceleration of the vehicle and what it is doing durign coast and steady speed ?
Nobody's sayign there are NO batteries but it wouldn't need the SHED LOAD that current hybrids are running :D
[quote]I got more belif that it has to be combined with a traditional combustion engine. Maybe a combustion engine only enabled on city driving and aceleration, disabled during freeway. who konw.[/quote]
Even if allowed to run at optimim efficiency, then an Otto will be WELL short of the efficiency of a Stirling -- or another "imporoved" combustion engien :D
[quote]So with out balance shafts,[/quote]
First balancer shafts are requried because of the ROTATION rpbblems.
Do you grasp that ?
So it is ONLY reciprocating weight that is the problem and the only part of a Revetec is the PISTON -- no strong conrod or crank out there :)
So you first recognise that it's a fraction of teh nromal engien weight. So you've done THE MOST IMPORTANT step already which is minimising the mass. Then if necessary they would apply for balance by multiple cylinders -- jstu in teh same way a V8 manages optmimum any paired Revetec piston seupt should.
[quote]1/2 of the conrod is considered to be oscilating and the other 1/2 is considered to be rotating. I did my homework on this, probartly the only thing about engine dynamics I still remember.[/quote]
That's a simplification that only works as long as you're not trygin to maximise the power output or the efficiency. Sadly I believe you've forgotten more than you think :D
[quote]2-strokes are the moust inviromental engines.[/quote}
BS and you provide the answer yourself - as I had already said.
[quote]consumtion of cylinder lube oil is a problem caused by the fact that no syntetic oil is made for this purpose.[/quote]
Rubbish :) You can't make an oil have long chains to maxinmise lubrication AND burn efficiently. You are thinking of only one thing at a time again.
let's now jsut save me the hassle. You're wrong.
[quote]About cylinder preshure I'm right. Even the preshure drops by 50% I will stil have 50% longer arm than the revetec. It all ends up in the same in the end.[/quote]
NO it doens't !!!
You are wrong.,
You are NOT thinking of the whole system again>
A crank does not match the optimal piston pressures because of the angles !! This is what the Revetec designer ( and many others over hte decades ) is trying to recover energy better.
Sorry, think about the CRANK positin as well as piston and do the vector force calucaltion and see how much is goin in to provide OUTPUT force.
[quote]There is no practical reason for adapting this design. I like it, it's a funn concept, but it's also all it is.[/quote]
Because you've NOT actually looked at the force vectors in all the components.
Do it, you will learn and understand.
[quote]I'm stil concerned about the bearing. Not anny ball bearing is 100% round, maybe it is 99,9999999%, but not 100% ball barings don't handle the same load as a plain baring and if anny contamination in the oil like soot or other particles it will just dig into the plain bearing and do no futher harm.
A ballbearing can more easely get permanent problems witch I'm shure you are avear off.[/quote]
Yeah but why is a ball bearing coming in to it ?
Do you mean NEEDLE bearings ?
Needle bearings can handle the pressures.
I think you are still thinking of only one thing at a time. Different materials could provide it, perhaps sacrificial. Oil bath coud deliver it at higher speeds onto the mating surface. WOudl still need strong material tho as it won't benefit from pressure build up from rotation the way a crank does.
But as you are not clearly aware the forces beign talked abotu are the SAME as a normal Gudgeon Pin on a piston is handling :D
So how come it survives there and yet won't here ??
MATERIALS and oil supply -- the challenge will be having ENOUGH pressure to ensure a minium thicnkess of oil to ride on.
Actually Matra the most efficient ICE in the world is a super huge 2 stroke diesel.
other than that Matra has done a good job pointing out innaccuracies I just like the fact that I have a design change that could allow the revetec to do so much better (reducing vibration, increase output speed, Improve lever length, lower weight, and it might just improve combustion?)
[quote=hightower99]Actually Matra the most efficient ICE in the world is a super huge 2 stroke diesel.[/quote]
Yeah but this isn't ultimateSHIPpage.com despite some of Matt's recent postings :D And ships can put huge scrubbers in the exhaust !!
One of the most efficient two strokers was the 1960s Honda 50cc race engine.
Revved to 24,000 needed 12 gears to be usable but SOUNDED SUPERB :D
[QUOTE=Matra et Alpine]
You got any actual figures.
All that I remember about it was platitudes.
ANd nobody says theire idea is a dog :)
You are AGAIN thinking of only one issue at a time>
The problem is only when you first start up. AS SAID, you would size the battery to manage the peak. You dont' accelerate a car for 20 seconds :D
Sorry but you're missing the whole point by being single-thinking. Build in what the Stirling engien is doing durign the acceleration of the vehicle and what it is doing durign coast and steady speed ?
Nobody's sayign there are NO batteries but it wouldn't need the SHED LOAD that current hybrids are running :D
Even if allowed to run at optimim efficiency, then an Otto will be WELL short of the efficiency of a Stirling -- or another "imporoved" combustion engien :D
First balancer shafts are requried because of the ROTATION rpbblems.
Do you grasp that ?
So it is ONLY reciprocating weight that is the problem and the only part of a Revetec is the PISTON -- no strong conrod or crank out there :)
So you first recognise that it's a fraction of teh nromal engien weight. So you've done THE MOST IMPORTANT step already which is minimising the mass. Then if necessary they would apply for balance by multiple cylinders -- jstu in teh same way a V8 manages optmimum any paired Revetec piston seupt should.
That's a simplification that only works as long as you're not trygin to maximise the power output or the efficiency. Sadly I believe you've forgotten more than you think :D
2-strokes are the moust inviromental engines.
BS and you provide the answer yourself - as I had already said.
Rubbish :) You can't make an oil have long chains to maxinmise lubrication AND burn efficiently. You are thinking of only one thing at a time again.
let's now jsut save me the hassle. You're wrong.
NO it doens't !!!
You are wrong.,
You are NOT thinking of the whole system again>
A crank does not match the optimal piston pressures because of the angles !! This is what the Revetec designer ( and many others over hte decades ) is trying to recover energy better.
Sorry, think about the CRANK positin as well as piston and do the vector force calucaltion and see how much is goin in to provide OUTPUT force.
Because you've NOT actually looked at the force vectors in all the components.
Do it, you will learn and understand.
Yeah but why is a ball bearing coming in to it ?
Do you mean NEEDLE bearings ?
Needle bearings can handle the pressures.
I think you are still thinking of only one thing at a time. Different materials could provide it, perhaps sacrificial. Oil bath coud deliver it at higher speeds onto the mating surface. WOudl still need strong material tho as it won't benefit from pressure build up from rotation the way a crank does.
But as you are not clearly aware the forces beign talked abotu are the SAME as a normal Gudgeon Pin on a piston is handling :D
So how come it survives there and yet won't here ??
MATERIALS and oil supply -- the challenge will be having ENOUGH pressure to ensure a minium thicnkess of oil to ride on.[/QUOTE]
No I'm not thinking at one thing at the time, but you are or like to think I am.
If you during aceleration neads to brake down because of a unekspected event and the acelerate again, your batteries would runn empthy befour the stirling would be able to take the load. Why do you think your so smart? don't you think there would be a hybrid stirling on someones model program allready if it was sutch a smart idea or are you one of those that belive there is a big conspiracy to keep up the oil price and sale?
A stirling is relative easy to build and sheap so it's clearly not a good idea since no one used it. I only see them as a way of energy recovery. Maybe you think that this hybrid thing is a new thing, but in the shipindustrie diesel generators running electric motors are a old idea from 1940. It only have advantage in load changing contitions and If the Stirling was a great idea This is probartly the place it would pop up first.
Yes I do understand that 1/2 and 1/2 is the simplefyed version, but do I really have to feed you everything in detail?
I understand why we got balance shafts and I also understand why counter weights are added to the crank. It's to counteract oscilating forces from the piston and 1/2 of the conroad(simplefyed version) How do you plan to fitt them to a revetec crank??? How will you counteract forces with a counter weight on a shaft rotating 1 time for every 6 time the force is aplied?
If you had a 4-cyl the engine would twist so to make vibrations not bother driver or/and pasangers you would nead a flat 8 who the hell would put that into there car?Packaging like you have pointed out yourself.
Just in case you stil don't understand the diference bewen a boxwe and a revetec.
[IMG]http://i43.photobucket.com/albums/e353/stian1979/boxervsrevetec.jpg[/IMG]
Packaging like you have pointed out yourself.
Nedle bearing's solve one problem, but only one. They still are not that happy about contamination in the oil unlike plain bearings that can handle some of it. They are just like the ballbearing not 100% round and you ad two new disadvantages and that is that they can't handle that high speed's and if they go wrong they can relly go wrong.
If you want to adapt plain bearing's for this aplication how would you do that? How do you want to make the surface big enough to get a hydrodynamical lubrication that will not brake. Maybe you think I only think at one thing at the time and I think you come up with problems instead of sulutions.
Again there is no gain in this construction. The only smal gain is that it can make heat from combustion into work befour it transmits into the cooling system. This is a peoblem that will be solved annyway when the fuel price make ceramics worth there price. I can also ad to the discusion that fuel don't exsplode, but it combust. At the time 40-50% of the stroke is done it's stil hydro carbons burning and ading energy and at this time the convencional crank is at it's maximum angle. so this is energy the revetec will transforme into rotation when it has only 50% of it's optimal angle.
1-1=0
P.S clearly your knowledge about 2-strokes is limited to Honda MB-5 and Yamaha DTR-50.
Did you hear about Cumer, Wickmann, B&W, Sulzer, Detroit Diesel or GM Diesel at all?
About the lubrication oil for cylinders You defently not know what this is about, do you really think that all two strokes use oil mixed in there fuel? Worng! as for using syntetic oil I actualy atended a cource with Mobil Oil where use and qualety of oil's where the ishue. If you can use a syntetic oil you can get a bether lubrication so you can use less oil to do the same job and that will my friend reduce the problem of burned oil. Do some back ground studys befour opening you mouth.
Lets say you are corect about the revetec. It delivers 3times the torque.:p
If a normal engine has a 30% efficensy and the revetec is able to transform 3 times more of the combustion into torque it would mean a efficensy of 90%
WOW!:eek:
I can actualy use the cooling water to wash a babys but and put my balls on the headers without feeling anny discomfort. :rolleyes:
[QUOTE=Matra et Alpine]Yeah but this isn't ultimateSHIPpage.com despite some of Matt's recent postings And ships can put huge scrubbers in the exhaust !!
[B]One of the most efficient two strokers was the 1960s Honda 50cc race engine.[/B]
Revved to 24,000 needed 12 gears to be usable but SOUNDED SUPERB[/QUOTE]
What??? I don't think so they guzzeled gas and oil like crazy for thier power output! The super large diesel I am talking about can reach 50% thermal efficiency!
Why is everybody still thinking about Stirlings and ceramic composites??? really people those are the old guesses at how to solve the heat problem but I know of a much better solution. A no-loss water injection system! inject water just as ignition is starting and most of the heat will be transformed into greater pressure, then you can have a lighter block and no radiators. (I hope everybody realises that it is not the heat but the pressure that makes things go round)
about the revetec vibrating too much, stian1979: the revetec can be made so that the pistons move just like in a normal boxer! (without all the side loading of course!)
[QUOTE=stian1979]Again there is no gain in this construction.[/QUOTE]
this statement is full of bologna! There is quite a nice gain in the revetec construction (flawed as it is)
[QUOTE=stian1979]The only smal gain is that it can make heat from combustion into work befour it transmits into the cooling system. This is a peoblem that will be solved annyway when the fuel price make ceramics worth there price.[/QUOTE]this statement shows that you misunderstand where the advantage lies in the revetec. Revetec is better because it transforms reciprocating motion into rotary motion at greater efficiency when there is much higher pressures in the cylinder! In fact it has a higher conversion efficiency at all times! The revetec represents a mechanical change to get higher mechanical efficiency, nowhere does it say that suddenly more heat is made into work (this is not how ICEs work!) And ceramics wil not change the world at all as it doesn't stop the heat from getting out anyways (ever heard of an exaust valve?)
[QUOTE=stian1979]I can also ad to the discusion that fuel don't exsplode, but it combust. At the time 40-50% of the stroke is done it's stil hydro carbons burning and ading energy and at this time the convencional crank is at it's maximum angle. so this is energy the revetec will transforme into rotation when it has only 50% of it's optimal angle.[/QUOTE]
This is an irrelavant and partially untrue statement. A good engine will combust more than 80% of the fuel in the cylinder before 20 deg ATDC the remaining power from the remaining gas is not enough to keep the pressure high through the expansion phase!(in other words the remaining gas doesn't add any power it simply slows the loss) Most conventional crank engines reach maxium conversion efficiency at around 60deg not 90deg like you think they do. And what are you talking about 50% of it's optimum angle?? the optimum angle is 90deg to radius this doesn't change for any engine! the revetec is always at about 90deg to the radius of the lever arm! (actual range is about 75-90deg when the piston is moving)
[QUOTE=stian1979]Lets say you are corect about the revetec. It delivers 3times the torque.
If a normal engine has a 30% efficensy and the revetec is able to transform 3 times more of the combustion into torque it would mean a efficensy of 90%
WOW!
I can actualy use the cooling water to wash a babys but and put my balls on the headers without feeling anny discomfort. [/QUOTE]
this is about as missled as I care to read. the 30% efficiency you are talking about in a normal engine is the thermal energy. (as in theretical total energy of fuel used divided by the output energy) the revetec is 3 times more mechanically efficient not thermally! you are relating numbers and doing top of the head math that shouldn't be! Both the revetec and a normal engine have the same amount of waste heat!
[quote=hightower99]What??? I don't think so they guzzeled gas and oil like crazy for thier power output! [/quote]
No they didnt'.
They competed the Isle of Man TT race on the SAME FUEL as their competitors and did it minutes faster :D
Also able to come back 40 years later and STILL rev to 20,000. All in a small town square with the sound echoing around :drool:
But you are right compared to TODAYS 2-strokes they ate oil. The Honda ceramic engine solved that -- but unfortunatley blew up every time it raced :D
[quote]The super large diesel I am talking about can reach 50% thermal efficiency![/quote]
Good point, I was stuck thinking petrol. Two stroke diesel better for sure :)
[quote]Why is everybody still thinking about Stirlings and ceramic composites???[/quote]
The Stirling is only going around because I picked the most ridiculous engine to operate a car with, but one with the capacity for the highest energy extraction.
[quote]A no-loss water injection system! inject water just as ignition is starting and most of the heat will be transformed into greater pressure, then you can have a lighter block and no radiators.[/quote]
But you also create acidic compounds and cause emissions issues. Can't remember the mix but it's not easy to remove needing two stage catalytics IIRC. It became a dead end for the car makers.
( Mind you with modern injection and better CFD in cylinder design -- maybe .... hmm got me thinking there, ht, any links to anyone doing current development ?? )
[/quote](I hope everybody realises that it is not the heat but the pressure that makes things go round)[/quote]
I think so because we've all been talking about pressure :D
Thanks for the rest, th, I'm close to delivering a MetA "response" to Stian who isn't listening and in his response where he SAYS he isn't thinking about one thing at a time goes on to prove it. You words were kinder than I would have managed this time around.
stian -- you are wrong. The evidence has been presented. My parting comment to you .... learn about the difference between peak and average and you would understand the Stirling/Hybrid and realise the HUGE mistake :) The rest of it ?? .... listen to ht :D
[QUOTE=Matra et Alpine]But you also create acidic compounds and cause emissions issues. Can't remember the mix but it's not easy to remove needing two stage catalytics IIRC. It became a dead end for the car makers.
( Mind you with modern injection and better CFD in cylinder design -- maybe .... hmm got me thinking there, ht, any links to anyone doing current development ?? )[/QUOTE]
this is what happened in the past. I believe that with a synthetic oil and better ring seal technology (it exists it just has to be used) that oil and water can be kept seperate for the most part and that when they do meet that they do not produce nasty compounds. I don't know of anyone looking into it right now, but I plan to try some test systems out on a turbo diesel. (When I turn the key what will happen?)
also I am talking about water injection as an entire cooling system not a intercooler or whatever.
also a good note that with water injection cooling with a no-loss system (as in you don't need to keep filling up on water) then efficiency can be raised very high as it is theretically possible to have exaust temperatures that are lower than intake after turbocharging temperatures. (a theretical but believeable example would be exaust temp of 20deg C and a intake after turbocharging temp of 300deg ((no intercooler)))
[QUOTE=hightower99]What??? I don't think so they guzzeled gas and oil like crazy for thier power output! The super large diesel I am talking about can reach 50% thermal efficiency![/QUOTE]
They are actualy betwen 50-55% nowdays.
[QUOTE=hightower99
Why is everybody still thinking about Stirlings and ceramic composites??? really people those are the old guesses at how to solve the heat problem but I know of a much better solution. A no-loss water injection system! inject water just as ignition is starting and most of the heat will be transformed into greater pressure, then you can have a lighter block and no radiators. (I hope everybody realises that it is not the heat but the pressure that makes things go round)[/QUOTE]
Water injection prove to giwe lover emisions but only 5-15% will give a power increase since more than that only will cool down the gasses to mutch and you will not have a power loss instead. Heat don't make things go around? Do you know that if air dubble it's temperature it will grow to 5 times the volum? This means that preshure will increase if the air has nowhere ti exspand.
[QUOTE=hightower99]
about the revetec vibrating too much, stian1979: the revetec can be made so that the pistons move just like in a normal boxer! (without all the side loading of course!)[/QUOTE]
Yes it can, but now it's geting more heavy again :(
[QUOTE=hightower99]
A good engine will combust more than 80% of the fuel in the cylinder before 20 deg ATDC the remaining power from the remaining gas is not enough to keep the pressure high through the expansion phase!(in other words the remaining gas doesn't add any power it simply slows the loss) Most conventional crank engines reach maxium conversion efficiency at around 60deg not 90deg like you think they do.[/QUOTE]
Diesel don't and this will probartly be the engine that will be more and more dominat because it don't bother that mutch about fuel qualety. You can runn it on LNG or asfalt(if you heat it up to 170C) Why do you thing big diesels at 10MW ++ has long stroke? Lots of rasons, but one of the is that it gets time to burn things that normal engines would not be able to combust.
[QUOTE=hightower99]this is about as missled as I care to read. the 30% efficiency you are talking about in a normal engine is the thermal energy. (as in theretical total energy of fuel used divided by the output energy) the revetec is 3 times more mechanically efficient not thermally! you are relating numbers and doing top of the head math that shouldn't be! Both the revetec and a normal engine have the same amount of waste heat![/QUOTE]
Yeah right. I would like to see a engine provide "3" times the torque at the same fuel consumption, same outer crank diameter and same heat loss. If they say a 5% or even 20% Increase due to bether transfere of forces I could buy it, but 3 times no. Sorry hightower.Scotch Yoke kan do the same just as good.
[QUOTE=Matra et Alpine]stian -- you are wrong. The evidence has been presented. My parting comment to you .... learn about the difference between peak and average and you would understand the Stirling/Hybrid and realise the HUGE mistake :) The rest of it ?? .... listen to ht :D[/QUOTE]
I know about all this mathers so I dear to say you are wrong. You have ben reading to mutch on revetec.com and svoloved the bait with the hock, line and maybe even the fisher. Try to make this engine yourself and runn it in MSC Adams. You still think your the tecnical Albert Einstein so why are no one running Hybrid Stirlings now? Do you belive in conspiracy to keep oil consumtion up and oil price up? If Stirling was so perfect as you try to make it seam every one would have a stirling hybrid in there model programe now.
If your only going to start it up and drive normaly to work it will probartly work just fine, but if you got to brake down to a dear crosing the road after only 30 secs of driving and then acelerate again the stirling would stil strugle to take load and the batterys would be empthy. It's not every day driving My consern is, but things that hapend that you did not exspect in the first place. This could be solved by using the electric motor as a generator to brake the weel's and runn the power to bateries by excitation of the motors, but now costs and system compeksety rise.
So strange the car industri don't jump on to your ideas of perfect engines and sulutions if they are so great.:D
[QUOTE=hightower99]this is what happened in the past. I believe that with a synthetic oil and better ring seal technology (it exists it just has to be used) that oil and water can be kept seperate for the most part and that when they do meet that they do not produce nasty compounds. I don't know of anyone looking into it right now, but I plan to try some test systems out on a turbo diesel. (When I turn the key what will happen?)
also I am talking about water injection as an entire cooling system not a intercooler or whatever.
also a good note that with water injection cooling with a no-loss system (as in you don't need to keep filling up on water) then efficiency can be raised very high as it is theretically possible to have exaust temperatures that are lower than intake after turbocharging temperatures. (a theretical but believeable example would be exaust temp of 20deg C and a intake after turbocharging temp of 300deg ((no intercooler)))[/QUOTE]
Like I say befour in this post it's limited how mutch you can spray in of water. If you increase preshure water will avaporate at a higher temperature. 60bar preshure is enough to keep water from not boiling even at 200C++
Also it has some other effects. H2O+Fe=? and heat make it go faster. And if it get out of the cylinder into the engine you have something called hydrocarbons or oil. H2O + hydro carbons can make organic acid's and I would not like that in my engine. Ceramics are interesting. No cooling neaded and you can wrap in the engine with insulation and water will not be a ishue if cylinder components are made from material that don't rust.
[url]http://www.autoblog.com/2005/12/09/bmw-turbosteamer-gets-hot-and-goes/[/url] some one got there eyes up for the future as I see it. Heat recovery.
[quote=hightower99]oil and water can be kept seperate for the most part and that when they do meet that they do not produce nasty compounds.[/quote]
I was meaning IN the combusino chamber and the mix of air and fuel.
Partial combustion generates acid compunds rahtehr than free gasses. So when it gets to teh catalyst, furirst it's done dmamge on teh way and second the catalyst has to first break down the acid and THEN combine to stabilise.
[quote]also I am talking about water injection as an entire cooling system not a intercooler or whatever.[/quote]
A given, intercooling and charge cooling are well undestood and used.
[quote]also a good note that with water injection cooling with a no-loss system [/quote]
Ohhh, wasn't thinking zero-loss :D
So how do you recover the water ?
Especially as some of it WILL have combined to form acid compounds.
How much energy does it take to keep a cold surface condensor cold ??
[quote=stian1979][URL="http://www.autoblog.com/2005/12/09/bmw-turbosteamer-gets-hot-and-goes/"]http://www.autoblog.com/2005/12/09/bmw-turbosteamer-gets-hot-and-goes/[/URL] some one got there eyes up for the future as I see it. Heat recovery.[/quote]
We discuss ed this one before.
Difficult to see how much it really benefits given teh extra weight it's carryign around :(
Seemed like it really would need triple expansion to recover more to warrant the weight. ( My subconscious has worked on that to and it woudln't work as it's NOT high pressure so the last piston would need to be the size of a large bucket :) )
to reply partly off-topic:
The gains of the CVT in the DAF f3 (or was it an f2 car ?) car were around and about 34-36 percent.On certain tracks even as high as 45-50% !!! No shifting time meant a huge advantage. DAF was planning more racing and sports activities to approve their image (especially in holland) before the passenger vehicle part of the company went bust and these racing activities were also cancelled. The CVT was used in the f3/f2 cars cos of the low amount of power. at the time a max. of 250 hp was there :( There are cvt's used in (experimental) trucks which have power up to 1000-1500 hp :D
[quote=drakkie]to reply partly off-topic:
The gains of the CVT in the DAF f3 (or was it an f2 car ?) car were around and about 34-36 percent.On certain tracks even as high as 45-50% !!! No shifting time meant a huge advantage.[/quote]
Not really.
[URL="http://www.f3history.co.uk/Manufacturers/DAF/daf.htm"]www.f3history.co.uk/Manufacturers/DAF/daf.htm[/URL]
[IMG]http://www.f3history.co.uk/Manufacturers/DAF/images/daf1.jpg[/IMG]
[quote] DAF was planning more racing and sports activities to approve their image (especially in holland) before the passenger vehicle part of the company went bust and these racing activities were also cancelled.[/quote]
The racing was cancelled LONG before DAF went bust.
[quote] The CVT was used in the f3/f2 cars cos of the low amount of power. at the time a max. of 250 hp was there :( There are cvt's used in (experimental) trucks which have power up to 1000-1500 hp :D[/quote]
Yeah but those dont' use belts (or they didnt' used to ) and so the losses in the transmission are quite high. Big and heavy too. Not an issue in a truck :D
Got any links for the progress on the experiments as it' skind of gone quiet :(
hly crap they need a special nerd section on this forum just for u 3 ...
[quote=KnifeEdge_2K1]hly crap they need a special nerd section on this forum just for u 3 ...[/quote]
Why ?
is it not better that everyoen gets the chance to learn more ?
Or are you only happy if we're talking about how much faster the car goes from STIKKAS :)
[QUOTE=stian1979]Water injection prove to giwe lover emisions but only 5-15% will give a power increase since more than that only will cool down the gasses to mutch and you will not have a power loss instead. Heat don't make things go around? [B]Do you know that if air dubble it's temperature it will grow to 5 times the volum?[/B] This means that preshure will increase if the air has nowhere ti exspand.[/QUOTE] HAHAHAHAHA! the highlighted part shows that you know nothing of physics, have you ever heard of Boyle's Law? it says that if you double the temperature of a gas then the volume of that gas will double in size (It will not expand by 5!)
the power generated by the water injection (Which I believe would work better if indirectly injected) happens when you inject enough water, so that the temperature is halved when the water turns to dry steam. the volume of the air will fall by half but the water will have expanded by more than 1600 times. So if you inject 1cubic centimeter of water dispersed throughout the cylinder as a fine mist, and the cylinder has a max volume of 500ccs then the water will create over 1600ccs of steam. Now lets say that the water is turned to steam when the piston is down far enough to have 100cc in it. the steam alone would give a pressure of 16 bar but it is with all the other gasses making the increase in pressure slightly more. So in the end you are looking at around 300 extra pounds of force per square inch and on a piston with 10 square inches (a small bore motor) then you are looking at 3000lbs. of extra force! that is more than alittle bit!
[QUOTE=stian1979]Yes it can, but now it's geting more heavy again[/QUOTE]
no it doesn't my design makes it even lighter!!!
[QUOTE=stian1979]Diesel don't and this will probartly be the engine that will be more and more dominat because it don't bother that mutch about fuel qualety. You can runn it on LNG or asfalt(if you heat it up to 170C) Why do you thing big diesels at 10MW ++ has long stroke? Lots of rasons, but one of the is that it gets time to burn things that normal engines would not be able to combust.[/QUOTE]
Actually diesels will be more and more popular because the fuel is cheaper and because they get better mileage and because you can tune them easier and because they can run on biodiesel (which is easier to make than bio gas) I will bet you that no car will have a diesel that runs on asphalt (because you can make about 30L of diesel out of 1L of asphalt!) and actually diesels due burn about 80% of the fuel before 20deg ATDC!
[QUOTE=stian1979]Yeah right. I would like to see a engine provide "3" times the torque at the same fuel consumption, [B]same outer crank diameter[/B] and [B]same heat loss[/B]. If they say a 5% or even 20% Increase due to bether transfere of forces I could buy it, but 3 times no. Sorry hightower.Scotch Yoke kan do the same just as good.[/QUOTE]
first there is not the same outer crank diameter (it starts out more than a normal engine of the same stroke and goes down) and there is a slightly lower in cylinder heat loss (higher average pressure firing due to short stroke) even so you have no reason to doubt the claims because if you look at a crankshaft it only ever reaches 95% conversion efficiency and only for a fraction of the full power stroke (the calculated average is 30% for most square engines) the revetec is constantly at 80-90% efficiency but the average is about 90% for the whole power stroke!... 90/30=3... yeah!
oh and the scoth yoke sucks to much friction and too heavy (as opposed to what the websites want you to think!)
[quote=hightower99]oh and the scoth yoke sucks to much friction and too heavy (as opposed to what the websites want you to think!)[/quote]
Still pretty good for the 50s tho' :D
With modern lighter strogner materials and better lubricants has anyone done any recent work on it.
For example for the Ford "traction drive" CVT they had mating surfaces between two rotating cones. The lubricant for IT was capable of preventing metal to metal contact at pressures up to 600,000 pounds per square inch against each other. ( Dont know how good an actual "lubricant" it was though as the purpose was to "stick" rather than "slide".
[QUOTE=hightower99]HAHAHAHAHA! the highlighted part shows that you know nothing of physics, have you ever heard of Boyle's Law? it says that if you double the temperature of a gas then the volume of that gas will double in size (It will not expand by 5!)[/QUOTE]
Oppsss. you just show you know nothing at all :D That depends on the gas my frien and I man enough to admit I'm wrong. Oxygen has a coefficient of (thermal) expansion at 4,86, but air has only 3,67 x 10^-3 K^-1
[QUOTE=hightower99]the power generated by the water injection (Which I believe would work better if indirectly injected) happens when you inject enough water, so that the temperature is halved when the water turns to dry steam. the volume of the air will fall by half but the water will have expanded by more than 1600 times. So if you inject 1cubic centimeter of water dispersed throughout the cylinder as a fine mist, and the cylinder has a max volume of 500ccs then the water will create over 1600ccs of steam. Now lets say that the water is turned to steam when the piston is down far enough to have 100cc in it. the steam alone would give a pressure of 16 bar but it is with all the other gasses making the increase in pressure slightly more. So in the end you are looking at around 300 extra pounds of force per square inch and on a piston with 10 square inches (a small bore motor) then you are looking at 3000lbs. of extra force! that is more than alittle bit!
[/QUOTE]
This is a fact with modifications. How manny times the water will exspand depends on preshure and temperature. If the preshure is 22090kPa the water would not exspand at all and if it's at 1kPa it will exspand 120000 times.
[QUOTE=hightower99]
no it doesn't my design makes it even lighter!!![/QUOTE]
I don't belive you unless it's not a revetec annymore. Please make me
[QUOTE=hightower99]
Actually diesels will be more and more popular because the fuel is cheaper and because they get better mileage and because you can tune them easier and because they can run on biodiesel (which is easier to make than bio gas) I will bet you that no car will have a diesel that runs on asphalt (because you can make about 30L of diesel out of 1L of asphalt!) and actually diesels due burn about 80% of the fuel before 20deg ATDC![/QUOTE]
I will not bet you on that, but there are diesels running on asfalt.
Large stroke ship's like you mention yourself befour.
[QUOTE=hightower99]
first there is not the same outer crank diameter (it starts out more than a normal engine of the same stroke and goes down) and there is a slightly lower in cylinder heat loss (higher average pressure firing due to short stroke) even so you have no reason to doubt the claims because if you look at a crankshaft it only ever reaches 95% conversion efficiency and only for a fraction of the full power stroke (the calculated average is 30% for most square engines) the revetec is constantly at 80-90% efficiency but the average is about 90% for the whole power stroke!... 90/30=3... yeah![/QUOTE]
OK! What ever make you happy, but I would not have a revetec even if you dip it in honey and roll it in marzipan.
[QUOTE=hightower99]oh and the scoth yoke sucks to much friction and too heavy (as opposed to what the websites want you to think!)[/QUOTE]
and the revetec don't? :D
Giwe me your e-mail so I can write you a long lether for apology the day I buy my first revetec powered car.
[QUOTE=Matra et Alpine]Still pretty good for the 50s tho' :D
With modern lighter strogner materials and better lubricants has anyone done any recent work on it.
[/QUOTE]
Actualy I think it more from the the 1890-1910 area.