Terraclean - snake oil or not?

The point of injecting it is to remove heat and cool the charge down, allowing you to advance the ignition. That gains you way more than the tiny bit of steam pressure you're talking about.

So, just to clarify, you're saying that the water's injected already "super-heated" rather than taking heat from the combustion?

If you do that it gets colder. Thermodynamics is really, really consistent

So how does the water get to the pressure and temperature to flash into superheated steam?

Didn't do anything of the sort on WWII aero engines, or GM Jetfire, or SAAB, or any water injection kit I've ever heard off.

So just to clarify , you don't think something like a turbocharger could get hot enough to boil water? Guess what - they do. And some have intercoolers, and guess what they do! Surprise!

Anwyay, this has all the hallmarks of a stupid Adrienne non argument so go f*ck yourself.

-- Spud

Probably not. I was talking in general about how it could be done, not how it was done. The fact that its not done like this probably means its not very efficient or worth the hassle, but I suspect the physics would work.

-- Spud

There's the clue, the physics says it doesn't work.

& amazingly they cool down whilst boiling it.

Why not get an A level and work up from that until you know instead of suspect?

Doesn't it? Ok, in that case you'll be able to provide a proof for that or at the very least a link to a web page that has one won't you.

-- Spud

EGR operation is for low load. Temperature rise in a turbo is due to compression, Tout = (1/effy) x Tin x (Pout/Pin)^((gamma-1)/gamma) (Physics not supposition or magic). There is no boost at low load (manifold is pulling vacuum), so there is NO temperature rise due to compression and very little heating of the air coming out of the turbo. Only source of heat is the very small amount it picks up from the warm compressor housing and that soon cools off. So at the time you need it you don't have a heat source for your superheated water.

Don't even think about finding a more reliable source of heat. It fails any cost benefit analysis. An EGR system is very much cheaper. The cost of a high pressure pump and injectors that can deliver water/steam direct to the cylinder will be comparable to that of a Diesel injection system. As water is corrosive and lacks lubrication for the injectors, it will be far less reliable or even more expensive.

If you hadn't told the world on here you could have patented it and then got the EU to obligingly ban use of EGR to force the adoption of your very expensive technology. (EU did this when they demanded use of catalytic converter and lambda sensor instead of lean burn technology)

I was waiting for Mr Wood to supply details since he seemed so sure of himself. I'm still waiting. Anyway, I wasn't talking about EGR so I'm not sure where you got that from.

And what time would I need it? I don't know what other posters were talking about but I was simply thinking of using waste heat from an intercooler which are only required when the turbo is hot due to the engine working hard.

Most probably, I never said anything about a practical system, just in theory you perhaps could reclaim some wasted energy by turning water into steam.

Wtf are you talking about?

-- Spud

On 27/04/2014 10:35, snipped-for-privacy@potato.field wrote:> On Sun, 27 Apr 2014 09:31:40 +0100 > Peter Hill wrote: >> On 26/04/2014 18:41, snipped-for-privacy@potato.field wrote: >>> On Fri, 25 Apr 2014 21:41:49 +0100 >>> "Duncan Wood" wrote: >>>> On Fri, 25 Apr 2014 20:22:28 +0100, wrote: >>>>> Probably not. I was talking in general about how it could be done, not >>>>> how >>>>> it was done. The fact that its not done like this probably means its not >>>>> very efficient or worth the hassle, but I suspect the physics would work. >>>> >>>> There's the clue, the physics says it doesn't work. >>> >>> Doesn't it? Ok, in that case you'll be able to provide a proof for that or >>> at the very least a link to a web page that has one won't you. >> >> EGR operation is for low load. Temperature rise in a turbo is due to >> compression, Tout = (1/effy) x Tin x (Pout/Pin)^((gamma-1)/gamma) >> (Physics not supposition or magic). There is no boost at low load > > I was waiting for Mr Wood to supply details since he seemed so sure of himself. > I'm still waiting. Anyway, I wasn't talking about EGR so I'm not sure where > you got that from. > >> (manifold is pulling vacuum), so there is NO temperature rise due to >> compression and very little heating of the air coming out of the turbo. >> Only source of heat is the very small amount it picks up from the warm >> compressor housing and that soon cools off. So at the time you need it >> you don't have a heat source for your superheated water. > > And what time would I need it? I don't know what other posters were talking > about but I was simply thinking of using waste heat from an intercooler which > are only required when the turbo is hot due to the engine working hard.

The premise of this run of this thread was that DavidR suggested that as it reduced cylinder temperature water injection could be used as an equivalent emission control to an EGR. Hence the need for it to work at low load.

Full load water injection into the manifold is an established simple means of controlling detonation and doesn't need to be made more complex by heating systems. For full load there is absolutely nothing to be gained from heating the water or direct injection of steam.

At full load you don't have enough temperature in turbo outlet air to achieve superheat. Most turbocharged engines run a pressure ratio of about 1.7 (10psi) Tout = (1/0.7) x 273+20 x (1.7)^((1.4-1)/1.4) = 214°C. and 2 (14.7psi) is considered high. Tout = (1/0.7) x 273+20 x (2)^((1.4-1)/1.4) = 237°C.

At full load cylinder pressure of 30bar the boiling temp required to obtain steam is 233.84°C.

You won't have have 99.4% efficient IC heat extraction so the water will not be at boiling point, never mind "superheat". You need a much higher temp than boiling as when superheated water flashes to steam it cools.

As for the original post about engine cleaner it's all crap. Old side valve engines needed a de-coke every year. Modern engines don't need a "clean" or de-coke even at very high mileage. I've striped an 20 year old engine at 180K miles and the backs of the inlet valves were clean and the deposits of carbon in the cylinder negligible. If an engine needs an internal clean then it needs fixing, valve stem seals, turbo that doesn't spew oil down the inlet, re-ring so breather system can cope with blow by.

It seems that egr just needs something that's comparatively inert.

Though perhaps you could explain something. Is there a reason for returning gas back to the manifold, instead of putting a variable restrictor in the exhaust to control cylinder flushing?

If I recall correctly, the Orbital 2-stroke used an exhaust restrictor.

10psi above atmospheric...

A diesel turbo ratio is about 2.5 to 3.

You explain things well. Though perhaps it is not so obvious to some that steam (gas) injection is something entirely different to water (liquid) injection. The common factor of being H2O is not the most significant property.

The point of injecting a liquid is that it can be done in the manifold without displacing a significant amount of intake air. To do gas injection without displacement it would need to go direct into the cylinder, perhaps during the compression stroke, and being a gas, a large entry aperture would be required.

5v per cylinder engines have been made... But wouldn't a 5th valve reduce the capacity of the other 4? And more work would need to be done during the compression, probably not recoverable. Looks like we just end up using energy to chase our tails.

Extra complexity and restriction to gas flow, versus the benefits of a (fractionally) more complete burn.

Of course, many engines now have direct injection of fuel straight into the cylinder. And, really, what's the practical difference between a finely atomised sprayed liquid and a gas?

Couldn't the same apply to four valves versus two?

not really since you can get 3 or more round valves conveniently into a circle whereas with two there will always be two big lumps of unused head left doing nothing

I've no doubt that manufacturers have done the cost/benefit analysis but it would be interesting to have reason instead of guesswork.

A lot.

The amount of (liquid) fuel injected is tiny. If my maths is approximately right, an engine delivering 250Nm uses in the order of 0.0001 litres of fuel for 2 litres of intake gas.

No. Individual valves in 4's are smaller than 2's but the combined aperture is greater. The combined aperture of 5 valves would be greater than 4. But if that 5th valve is used to introduce a gas that is effectively useless, that would reduce the aperture of the 4 remainder.

On 27/04/2014 17:56, Mrcheerful wrote:

Liquid has to evaporate before it can burn and that cools the charge. The blobs that don't evaporate fully, boil during combustion. Then some rings of carbon don't get broken and can't burn to make CO2 but do get striped of hydrogen so make carbon soot instead. The PM that Diesels now have to fit filters to catch.

Don't get any carbon deposits with LPG as it's short chain is much easier to break. Lack of charge cooling is compensated for by 106 RON octane. There are at least 2 manifold liquid phase injection LPG systems. I've not heard of anyone using LPG on direct injection yet. The pumps are probably not compatible with poor lubrication properties of LPG but as the pressure is high there is little chance of the LPG turning to vapour in the system. As a lot of Europe has now made it illegal to tamper with the OEM fuel system it's not possible to retro fit in those states, so market is too small to warrant development costs.

Very few people have experimented with truly vaporised (as in boiled) petrol, rather than finely atomised. One was put in prison for public safety after the first caught fire and I believe the 2nd exploded.

There are always some new candidates. The large plastic bottle with petrol sloshing about and 1 gall of air/vapour mix says it all for the safety of this system, though he does seem to have 2 anti-backfire valves in the vapour mix inlets. Unlike a petrol tank which only draws in air as the fuel is used so has petrol, vapour and air in a fully saturated mix that is too rich to explode, this is constantly drawing in fresh air and the air/vapour mix is explosive, so he has a 1 gallon petrol bomb under his bonnet. A candidate for a Darwin award in the making? Such crude fuel systems called a "surface carburettor" were abandoned (by the sane) well before WW1 as the many fires resulted in poor press and sales for vehicles that didn't use the new "automatic" spray jet carburettor. So many have gone up in flames that it's really not worth the risk of attempting to run these historic museum vehicles. Any sane person would adapt LPG systems (vapouriser/boiler, mixer/injector) that are proven to deliver safe use of a boiling liquid vapour fuel. These keep the vapour separate from air right up the point of mixing. Of course you do have to keep the petrol as vapour throughout the system and stop it condensing back to liquid in the cold inlet air. You would have to wait for it "get up" vapour before using it and purge the system of petrol that condensed while it was off.

Valve flow area is circumference x lift. Lift is usually about 1/4 of valve diameter - it's not worth lifting any more as then the port area less the valve stem is the limitation. As most of exhaust gas is blown out under pressure and inlet only has limited suction. 4 valve heads have bigger inlet valves compared to exhaust - typically inlet 15-20% bigger to give about 40-50% more inlet flow area. While 5 valves are all usually the same size and by having 3 inlet and 2 exhaust have the same

3:2 relative inlet/exhaust area as a 4 valve. 6 valves with 3 inlet and exhaust need bigger inlet valves. More but smaller valves will have less lift for same flow area. Having smaller valves allows more radical valve timing and higher rpm.

Yamaha looked at 5, 6 and 7 before using 5 but have reverted to 4 - mainly for cost.

Honda went for 8 in the NR500 but that was really a V8 with co-joined cylinders and not a V4.

Rudge in the 1930's tried 2, 3 with both 2 inlet 1 exhaust and 2 exhaust

1 inlet and 4. Eventually producing a radial 4 valve head before WWII. Hmm that Chevy patent has rockers on eccentric shafts, DOHC 4 valve/cylinder with Variable valve timing/lift was invented in 1917. Only took 90 years for it to become universal.

on 27/04/2014, snipped-for-privacy@potato.field supposed :

The heat in the intercooler is very low level, so it wouldn't be easy to use it.