Super Moderator
hmmm, for that to work I think you woudl need MASSIVE compression as if you do not the initial creation of super heated steam will actually prevent the on-going wave front of the combustino gasses.Originally Posted by hightower99
I'll do the math with my BP petrochemicals friend tonight over a beer -- so no guarantees of accuracy
"A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'
Enthusiast
Use. water. injection. to. replace. the. radiator. ?.
*chuckle* Well, let us know how that works for ya.
Enthusiast
fark, ok this is one helluva convo, ive just read page 1 through to 7, and possibly 30% of the terminology and concepts i understand. Matra ya bastard, i envy your intelligence and understanding of cars
Btw, back on topic (well the thread title) It's an interesting concept that I hope comes into at least (small) production to show the world its potential and further development if it were provided with more funding. There is always room for improvement in an engine, and simply bagging it in current stage wouldn't be justifiable if there are already plans for improvements with fuel efficiency and what not.
House said the perfect woman was a man...now im all confused!!
What is a mile long and hasn't had sex?
- The line for the PS3
Enthusiast
who said use water cooling to replace radiator ??water cooling will cool the intake charge, it doesnt remove heat from the block and engine parts
Enthusiast
development in current combustion powered engines i think is a stupid concept, we're gonna run outta fossil fuels soon, thus it wont warrant more development into something we wont be able to use into the forseable future, better invest in hydrogen power, and electric cars which can last longer then an ipod and without battery problems
Enthusiast
it doesn't in current applications but I suggested that it is possible and that it would help!who said use water cooling to replace radiator ??water cooling will cool the intake charge, it doesnt remove heat from the block and engine parts
we are not going to run out of fossil fuels soon (unless you consider 75-100 years soon?) and even when we due no other form of engine can beat ICEs for the energy concentration!!! Developments in ICE technology is what is going to make things better. Diesels will become the most popular engines because they can run cheaply on totally organic fuel (renewable) and then there is always metal nano dust (reuseable) and hydrogen (renewable)... Electric cars are great for in-city non poluting transport but to fly jets and drive any sort of equipment long distances you are going to need an ICE!development in current combustion powered engines i think is a stupid concept, we're gonna run outta fossil fuels soon, thus it wont warrant more development into something we wont be able to use into the forseable future, better invest in hydrogen power, and electric cars which can last longer then an ipod and without battery problems
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
Enthusiast
depends if you want to run your car on coal or not
there are very few untapped oil fields left and there aren't any new ones being made anytime soon
How can men use sex to get what they want?
Sex is what they want. - Frasier
Enthusiast
75-100 years is when the crude oil supply will be too small and expensive to get to be profitable...depends if you want to run your car on coal or not
there are very few untapped oil fields left and there aren't any new ones being made anytime soon
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
Enthusiast
sounds like an extreme upper bound to me...
How can men use sex to get what they want?
Sex is what they want. - Frasier
Enthusiast
not really there is 25 years there.... Everyone has atleast 75 years of motoring left before everything stops and it could go on for another 25 years after that... but even after 100 years there will still be fuels for use in ICEs
Power, whether measured as HP, PS, or KW is what accelerates cars and gets it up to top speed. Power also determines how far you take a wall when you hit it
Engine torque is an illusion.
Enthusiast
under current consumption patterns and rates this estimate MAY be true, but developing countries are increasing their ussage of fossil fuels and such to maintain/increase this growth, as a result of getting richer they'll also buy cars
you could argue that cars are becoming more efficient but imho i dont think that they'll become mainstream quick enough to do any measurable good
all of this is besides the point since we know that the supply of fossil fuels wont last forever so why not get an early start on an alternative hopefully renewable and non poluting fuel ??
The Voice of Reason
It is physically impossibly for the water not to remove heat from the block and engine parts. Especially since water has such a massive specific heat capacity, it's quite a substantial amount of cooling in the case of water injection.
You guys are very quick to assume. The fact that you've never heard of it has little to do with the possibility of it being a viable idea. It's not just a good idea either - it actually exists.
Bruce Crower (I'm sure you've heard of Crower internals) has invented a highly efficient single cylinder 6-stroke gas/steam engine. Not only does the water injection/steam help make the fuel last longer, but it helps in the cooling process as well. The engine doesn't require a radiator.
Novice
I just read this whole page from 1 to 7, and can't believe what I am reading. stian1979 is the only person here that understands what's happening here.
The revetec engine is equivalent to a conventional engine with a 3:1 reduction built in to it. If it's output shaft is doing 3,000rpm, then it's camshafts, valvetrain, and pistons are doing an effective 9,000rpm.
Therefore it looks impressive to the untrained eye.
If you don't believe the 3:1 thing, then just look at it.
On a normal engine the crank runs the camshafts at a ratio of 1:2. If you have 10 teeth on your crank pulley, you have 20 teeth on your crank pulley.
Because the revetec is a 3-lobe design, it is like having the output shaft (crank) geared down 3:1. So you need to gear the drive to the cams back up 3:1 to get the same piston and cam cycle ratio. So you basically need to have 3 x the normal 1:2 ratio. Or a ratio of 3:2. So if the crank pulley has 30 teeth, then the camshaft pulleys will have 20 teeth. Quite the opposite to the normal engine, and look, it does!!!
Novice
So what does the 3:1 ratio mean? It means they are cheating in some of their marketing.
Take their latest engine test results;
http://www.revetec.com/files/Announc...2004.05.06.pdf
The engine they specify is 1.38L. 94mm bore with 50mm stroke. That bore and stroke on a conventional engine gives 1.38L, so they are not compensating for the 3:1 ratio in their effective volume calculation.
So they have tested the engine and get 57kW@4,120rpm. With the effective 3:1 reduction taking into account it is really doing 57kW@12,360rpm.
And they get 140Nm@3,650rpm. But because of the 3:1 ratio they are really getting an effective 47Nm@10,950rpm, and then gearing it down so it looks more impressive. It's false advertising really.
And those effective rpms are correct, because that is what the piston speeds and valve train speeds are equivalent to.
Now they compare their relatively high performance engine (Haltech injection, custom made everything, probably individual throttle bodies) to a low performance production toyota engine. That's not very fair. They then say "Not only are we producing the same power with a smaller capacity engine, but we are doing it at a lower rev which saves fuel. We also are producing more torque than the Prius at a lower rev with a far shorter stroke."
Lower rev so it saves fuel? what a crock. That is so misleading. Because the revetec pistons go up and down 3 times as much, it will induce 3 times as much air into the engine, and therefore use 3 times as much fuel for any given rpm.
But why not compare the revetec 1.38L engine to a conventional engine in a similar state of tune? One that revs to around 12,000rpm?
Well that would be something like the Kawasaki ZX-14 engine. It is 1.35L, it makes about 140kW @ 10,000rpm, and about 160Nm at about 8,000rpm.
These figures absolutely embarrass the revetec motor. There is no comparison at all!!!
Or the other way to look at it is to compare a ZX-14 running through a 3:1 reduction box, and the revetec.
So the ZX-14 would now be 140kW @ 3,333rpm, and 480Nm @ 2,666rpm.
Compared to 57kW @ 4,120rpm and 140Nm @ 3,650rpm.
Can you people see the difference now???
That shows the revetc is working harder than the ZX-14 engine, and making way way less power and torque!
Furniture
so basically it's competitive against similar sized car engines but redundant because bike engines do the same thing but much better?
Andreas Preuninger, Manager of Porsche High Performance Cars: "Grandmas can use paddles. They aren't challenging."
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