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  • Water/alcohol injection and diesel engines

    Hello all!

    I've just bought a water/alcohol injection kit from the States and am about to fit it to my Peugeot 306 turbo-diesel. The kit consists of a high pressure (150 psi) pump, a tiny injector nozzle and some other goodies.

    I was wondering if anyone had had any experience with water/alcohol injection in diesel engines? There seems to be a wealth of information on the internet about water injection for spark ignition engines, but very little for compression ignition engines.

    Any ideas/input anyone?

  • #2
    Re: Water/alcohol injection and diesel engines

    Hey Tom,

    I have been reading up on water injection and am in the process of making up a DIY system for my merc. I am guessing you may have bought an aquamist system by your description of the 150 PSI pump as I think they are the people pushing the high pressure benifits. Those systems seem to achive a real water "fog" rather than anything else and seem to be the rolls Royce of what is available.

    I was looking at water injection to prevent any problems with ring coking and to keep the combustion chambers and components clean when using WVO blended fuel and in case the WVO conversion I am planing isn't what it should be.

    I know with water/ alcohol there is supposed to be a performance boost on petrol engines but I can't recall seeing anything about the effects on diesel engines. I think it would be of greatest benifit to Turbo engines in lowering the elevated intake air temps. Wether a diesel would have to have it's pump ajusted to take effect of this or not being they normally run excess air anyway, I don't know.

    I am thinking water is maybe a technology the the diesel community hasn't really embraced as yet.
    The only thing I have seen of it in diesel applications was to try and lower EGT's. This is a performance application for people who are either towing or overfueling their engines for max power.
    The more reliable and common opinion I have seen of this is it does nothing to nothing of any consequence in this area.

    I have mucked around with putting water into my diesel generator and I am amazed at the amount the thing will ingest while not changing the RPM or engine note a bit. During one of my tests a slipup meant an amazing amount of water went in the thing and I was quite surprised I didn't hydraulic it and have it throw a leg out of bed. When running the water it does tend to smoke a little more than usual but this clear up when the water is removed and their is less smoke than normal afterwards which leads me to think it is removing something from the engine in the way of deposits.

    If water injection works as I believe it should as a way of keeping the combustion chambers and rings clean, I would think it would be something that every one running bio or WVO would be interested to use as a preventative of coking problems. It would be really great if you could pull and photograph an injector then run the car some miles and pull it again to see if there are any cleaning effects.

    I will be really interested to see what your experience with this is Tom and how you get on with it.
    What are you hoping to achieve with the water injection and are you still running your browns gas generator?

    Comment


    • #3
      Re: Water/alcohol injection and diesel engines

      Hi David!

      The kit that I bought is one from coolingmist.com, which is perhaps not quite up to the standard of Aquamist, but is still good nonetheless! You're right about the "fogging" of the water - at 150 psi through the tiny injector it's a very fine mist. I don't know why, but I've always had a "thing" for water injection ever since I learned about it. I think the idea of using water to augment the performance of an engine is a cool idea, even if it does sound ridiculous at first!

      I think you're correct about the diesel community not having embraced the idea of water injection for compression ignition engines - I struggled to find anything substantial on the internet! I'm hoping I'll get some good data though with my trials!

      I'm interested in the tests you mentioned - was it just straight water you were putting into your diesel generator? I would have loved to have seen the results - they sound kind of promising actually! I wonder what might happen if water and alcohol were used? Like you say, it's surprising that the engine didn't hydraulic! I wonder just how much water is too much? I hope I don't find that out soon!

      I guess the main reason for wanting to use the kit is primarily to cool the intake charge. I've somehow got it stuck in my head that the intercooler on my Peugeot gets heatsoaked easily. I though that water injection might help to cool the air after it's passed through the intercooler. I like the idea of it cleaning the combustion chamber too - surely this would be of benefit in regards to longevity of a diesel engine? Providing it works as expected, it might be of some benefit to the SVO/WVO users out there! I don't know how much of a problem carbon build up is, but any data I can throw into the communal pool of knowledge might be of use to someone.

      Yep, I'm still using the Brown's Gas! I did a test with it by using the car's alternator to provide about 17 amps to the generator. It worked well and was as easy as pie to turn it on considering I had a little switch mounted on the dash! Anyway, by powering the device this way it seemed as though I broke even, so no gain. I guess one test doesn't prove much though does it? Anyway, I began to think that the output does not exceed the input by using the alternator, so I thought of another way to power the generator. I decided to revert back to using that big Iveco truck battery I first started out with. When I first began with the big battery I was charging it with a battery charger via the mains. Someone pointed out that the electricity used would still cost me money and was generated using coal - a non-renewable resource. I took this on board and began to think some more, as indirectly using coal to power the generator goes against what I'm trying to do. Anyway, I splashed out and bought a solar panel on eBay! The solar panel I bought wasn't cheap, but it has a fairly good output on a sunny day! When I'm not using the car I just charge the battery using the solar panel! Mind you, it has to be a somewhat sunny day, otherwise I still have a flat battery! My next step is to buy a few more panels to decrease charging time. Pretty cool!

      As soon as I do a few trials with the water/alcohol injection I'll post up the results! The first trial I'll do will be with a mixture of 50% demineralised water, 25% ethanol and 25% methanol. Hopefully I'll get some good results to share!

      Comment


      • #4
        Re: Water/alcohol injection and diesel engines

        HI, I'm also interested in water injection as I'm going to change my turbo triton over to SVO and would like to be sure there is no coking. I had an experience with water going into the engine on my boat. She has a 671GM in her which is a two stroke common rail supercharged diesel and came out of a tank from the 40's-50's, she's been fully rebuilt before I got her, runs and starts like a dream and loves BD100. Even on really cold days she starts instantly (Tas). But it's a bit weird smelling fish and chips at sea.

        Anyway one trip we filled up at a place we normally don't use and when we switched over to the just filled tanks, it wasn't long before she was pouring out huge amounts of white smoke, but wasn't slowing down. A check of the tanks filters, showed them full of emulsified diesel and water. She ran like that for more than 15 mins as we worked out the problems and changed to clean tanks. We couldn't stop her as we were at sea and needed steerage in the weather. Even though she went well, we did notice a distinct change in engine revs and smoother running after. I haven't repeated the episode as the amount of smoke was enough for it to be noticed by a passing boat and then emergency services contacted us to see if we were on fire. But its an interesting proposition and I will try it with my 12hp Honda diesel generator once I change that to SVO. First got to work out how to make a pre-heater for her and am experimenting with taking the heat from the exhaust by coiling the SVO pipes around the exhaust.

        Don't quote me, but I was told the reason water in your fuel tank is not good and stops the engine is because it bubbles in the injector system and stops fuel flow, like air. I know the 671GM is designed to run on contaminated fuel as they are used to power tanks and bad fuel is always a problem in war zones.

        Comment


        • #5
          Re: Water/alcohol injection and diesel engines

          Today I set up my DIY water injection system using a pump and a spray jet.

          I wired the pump into the switch for the kickdown for the auto on my 300D.
          One of the 2 wires is powered (which I discovered only after first locating a switched circuit) so the connection was simple as tapping into the kickdown switch and wireing a ground. As soon as the throttle is full open and the detent switch is pressed, the water will spray.

          I am using a a Commodore washer bottle and pump and the pressure seems surprisingly high. For the Water jet, I am just using a plastic garden type mist sprayer head. Certainly the spray is nothing like the fog of some systems but given the price difference, this is hardly surprising. I will look at getting a better nozzle but for the moment the system was only rigged up sufficently to test and evaluate it over a short term.

          I fashioned up the crudest of brackets to fire the spray straight into the intake manifold. As I tested before, the spray seems to be broken up further by the air entering the manifold.
          I measured the output of the system before installing it at about 300ML a minute. This was higher than I was intending but subsequent testing has shown the engine seems quite happy with this flow rate.

          Once I was set up, I took the car for a good run and after some time, the car seemed to be running the tinyest bit better. Perhaps the water had removed some deposits quite quickly or it could have been the fact I was holding the engine to quite high revs through the gears and giving the thing an itialian tune up. My aim with adding a water system was not to improve performance but rather to prevent some engine problems so I wasn't expecting any differences in the way the car went.

          When I came back from the first run, I spotted some methanol in the garage and thought I would try a mix with water to see if there was any difference. I made up a 50/50 mix and put this in the washer bottle after emptying the remaining water.

          On my second run I didn't notice any difference for a while but then the car started performing noticably better. My tests were basically some fangs through the gears and pulling up hills and if the car isn't noticably quicker in accelleration, it sure as hell feels like it.

          I tried some standing starts off the lights and instead of the car moving off like a tired snail, the thing literally lept off the line (wih a rather impressive rise of the bonnet thanks to the ineffective front shocks) and I was able to leave the traffic behind and got to 60 far quicker than ever before.

          As it is real easy to let hope and imagination take over in seat of the pants testing, I went home and collected no.1 Son and told him helga had a problem and wasn't running very well and I wanted him to come with me to listen to any noises. After a couple of launches and runs through the gears I asked him if he noticed how much slower she was running and was met with " You have to be kidding Dad, she's never gone this fast before!"

          Certainly this is all heresay and I'm waiting to see if my gut feelings are borne out against the clock. It's pretty hard to find a quiet bit of road round my way at 5:30 on a weekday afternoon to do some half serious timing runs so I'll have to wait till the weekend and do a bunch of runs to see how she goes when actually measured time wise. It is possible that the water and reving has cleaned the injectors or disloged some deposits and the tests I run won't show much.
          If that is the case I will still be happy because the car feels far better and more driveable than it ever has before.

          Using a Fuel flow/HP calculator, I worked out that a 50/50 mix of water-Meth is supplying enough meth as a fuel to support 10-13 Horsepower. Wether the meth is being burnt like a fuel and the energy is being released as to provide that amount of additional power, I am not sure but certainly my seat of the pants tests suggest it is not beyond the realms of possibility.

          I can't provide much in the way of facts just yet but my feelings are that the water is doing something and the difference with the Meth is far too significant to be imagination or wishful thinking alone.

          Perhaps the low power output of the standard Merc engine shows up any gains a lot more significantly that would occour in a higher powered and more lively car.

          I'll run some numbers the weekend and find out!

          Comment


          • #6
            Re: Water/alcohol injection and diesel engines

            hi all good reading.
            would there be any advantages on a normally aspirated diesel, and would it actually remove years of crud.
            {old 2h landcruiser} on wvo,2 tank ,heated
            thanks

            Comment


            • #7
              Re: Water/alcohol injection and diesel engines

              Hello David!

              Congrats on getting your water injection system going - the results you've experienced thus far sound very encouraging! I like the sound of what might happen with my Peugeot!

              I like the idea of using a nozzle from a garden irrigation system - that's quite clever thinking! You can score fogging nozzles on eBay for relatively cheap prices, but if you've got a lathe and some tiny (very tiny!) drill bits there's no reason why you couldn't make your own. They'd have to be incredibly small drill bits though - I think the nozzle I've got is 0.3 millimetres!

              So there was a significant difference when using methanol mixed with the water? I'm going to hazard a guess and say that it is acting as a kind of supplementary fuel. I wonder if it augments the actual combustion of diesel any?

              I had an idea that might give you another gain David - when you next make up a solution of 50/50% water/methanol, pop it in the freezer overnight and see if it makes a difference when injected! I've heard of people putting ice into the water reservoir of their water injection systems, but if you've got methanol in with the water it shouldn't freeze solid.

              I think we're onto a winner here David! I hope a few more folks fit similar systems. I've got a feeling that it would definitely benefit the SVO/WVO folks out there. I hope I get as good a gain with the Peugeot as you have with Helga!

              Comment


              • #8
                Re: Water/alcohol injection and diesel engines

                I also experimented with water / alcohol injection a few years ago. In my Mazda Capella 2.0 litre NA diesel, I was able to provide a 10-20% power boost using a similar washer pump/garden nozzle arrangement. I also decided on a throttle position switch to provide the 'boost' at max pedal depression. I added a switch, as the Capella was a 5 speed manual.

                When I replaced the engine, I installed the supercharged version of this engine and did not reinstall the injection system.

                When I bought the current MB Fatmobile, in 2003, I installed a similar system, but used a nozzle which had a brass insert.

                I did not notice any specific improvements using water injection on the 300D. On a long run, the nozzle was ingested by the engine and the brass insert became embedded in the piston of #4 pot. This may have been due to the high ambient temperature causing the nozzle to loosen in the plastic 'riser' and be sucked into the engine, causing a loud tapping at all RPM. I continued to drive the car for a while before having the head off and removing the offending insert. There seems to be no long term adverse impact from the ingestion.
                A word of CAUTION!
                Just be sure that the nozzles you use are all plastic, as any metal bits may cause major impacts on the engine internals.

                I was lucky that the insert lodged in the piston. If it had caught in a closing valve, I may have bent the valve or damaged other parts more seriously.

                I hadn't managed to trial the 50/50 water/alcohol in my 300D and have been reluctant to experiment further since the incident.
                Tony
                Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.

                Current Vehicles in stable:
                '06 Musso Sports 4X4 Manual Crew Cab tray back.
                '04 Rexton 4X4 Automatic SUV
                '2014 Toyota Prius (on ULP) - Wife's car

                Previous Vehicles:
                '90 Mazda Capella. (2000 - 2003) My first Fatmobile. Converted to fun on veggie oil with a 2 tank setup.
                '80 Mercedes 300D. 2 tank conversion [Sold]
                '84 Mercedes 300D. 1 tank, no conversion. Replaced engine with rebuilt OM617A turbodiesel engine. Finally had good power. Engine donor for W123 coupe. (body parted out and carcass sold for scrap.)
                '85 Mercedes Benz W123 300CD Turbodiesel
                '99 Mercedes W202 C250 Turbodiesel (my darling Wife's car)[sold]
                '98 Mercedes W202 C250 Turbodiesel (my car)[sold]
                '06 Musso Sports Crew Cab well body. [Head gasket blew!]
                '04 Rexton SUV 2.9L Turbodiesel same as Musso - Our Family car.
                '06 Musso sports Crew Cab Trayback - My hack (no air cond, no heater).

                Searching the Biofuels Forum using Google
                Adding images and/or documents to your posts

                Comment


                • #9
                  Re: Water/alcohol injection and diesel engines

                  Hi Dagwill,

                  My Merc is the non turbo version (unfortunately) and driving the car round today for a while, I am more than convinced the water has already made a difference. I just ran it with water today rather than the water/meth mix and while I don't detect any difference in power per se, there is no doubt it is running "sweeter".

                  While with the water alone I don't detect any more power, it does feel a lot more responsive and more willing to kick down in the auto and pull out of tight corners a lot more briskly. I also notice it is holding the gears a lot longer and revving out better. When she is off song like with a partially blocked filter, it tends to change up gears very quickly and then lumber along like it is dragging the anchor from a battle ship behind it. Certainly now it is far more sprightly than ever before and much more like a small petrol car.

                  I fully expected any noticeable changes to take some time to appear as I would have thought any cleaning action would have taken a while work. Perhaps something in my engine was especially dirty and some major crud has been removed already. I don't know what this could be but I'm happy with the difference in the way the car is going anyway.

                  For a short term test, there is no reason why you couldn't wire in the existing washer bottle in your car as long as it had a decent output, which would again reduce the cost to under $10 to give the idea a try. The misting nozzles I used are available in the garden section of Kmart or Bunning’s and I think I bought a card of 10 for about $4.

                  Tom,
                  I have to say I am rather excited about what I have experienced so far but also very cautious that I am not imagining things that aren’t happening. That said, tonight I went for a ride in another car the same as mine and it seemed to go much better than mine did before the water setup. This would seem to suggest that what I am feeling is not imagined and the benefits I am seeing are just the effect of the water removing some thing that was not allowing the car to perform as it should have been. I am now wondering if I do some timing runs the numbers will be what other people are getting anyway so the results won’t seem any big deal.

                  At the moment though, I am convinced that already the water has done something to improve the performance of the car even if it is only bringing it back to what it should have been in the first place.

                  The garden spray nozzle produces both some very fine spray and some very coarse spray as well but I have noticed the water is broken up a lot just by the turbulence of the air. I think if the system I have works, a system like you have should produce excellent results.
                  I think a fine spray would lower the air temp through better atomization and perhaps also allow the water vapor to permeate into parts of the engine like behind the rings and have its effect there. Now I am confident water injection does hold worthwhile benefits, I will invest in a better nozzle and set the system up properly.
                  I was reading up some more on water/meth mixes and found a site that did suggest that the meth would burn in a diesel and provide more power. They suggested that meth could be injected at up to 100% for max power gains and some people were using it this way for towing. I was suggested that the meth provided more power with less of an increase in EGT's than other " fuels" such as gas or higher diesel injection rates.
                  There were some other statements made on the same site which were categorically wrong so the statement about the meth as fuel may or may not be creditable.

                  I don’t know if the meth is helping the Diesel combustion in any way but I can see no reason why it would not act as a supplementary fuel in itself just the same as adding LPG fumigation. At the rate my system is injecting, a pure methanol solution should conservatively be worth another 30Hp. I am going to try some different mixes in acceleration tests to see if this theory can be seen in the vehicle performance.

                  If it does show up, it would be akin to liquid Nitrous oxide for diesels! ….. Which also makes me wonder if it was as easy as this to boost HP, why someone hasn’t come up with it before??

                  Comment


                  • #10
                    Re: Water/alcohol injection and diesel engines

                    The most important area for good air flow is the region of 10-15mm either side of the valve seat. On high performance engines you often see extensive head work related to the valve seats; triple angle grinds, relieving the valves in the combustion chamber, swirl polishing the underside of the valve, etc.

                    Because this area is so critical, racing crews spend a lot of time removing heads and cleaning this area of any carbon build-up and then lightly resurface the valve seat.

                    I watched Paul Newman's pit crew use an alternative method of cleaning out the carbon on his racing Nissan - they poured water down the intake of the running engine after each race.

                    If you have ever looked at a valve removed from a well used street engine, the amount of carbon build up on the underside of the intake valve can be considerable. That carbon disrupts the airflow by causing turbulence. Likewise, on the inside of the combustion chamber just after the valve seat the carbon can build up and cause turbulence, if not partially block the flow at the lower valve lifts.

                    I expect that the improvements you fellows have experienced is the removal of some of the carbon in that critical area.

                    I am now thinking of running some water through my engine to give it a cheap "tune-up", sure beats pulling the head off.

                    Comment


                    • #11
                      Re: Water/alcohol injection and diesel engines

                      Hi Terry,

                      I tried pouring water down the intake several times but couldn't really tell if the percived difference in the way the engine ran was real or imagined as it was very slight if anything at all.

                      Perhaps there was a significant buildup in my engine that has required a more sustained application of the water to remove. Given what you say, perhaps in my engine being an IDI type that the water has cleaned out some buildup in the pre combustion area as well which is helping things?

                      I have no idea of what has happend but I am sure happy with the results!

                      Comment


                      • #12
                        Re: Water/alcohol injection and diesel engines

                        Hi David,

                        Any power gains you noticed by the addition of your water/methanol injection system will come from two the sources you have already indicated.

                        1. Lowering of the inlet air temperature due to latent heat of evaporation
                        2. Additional fuel load of the methanol

                        I thought these numbers might be useful in helping to visualise what is going on in the inlet manifold

                        Latent Heat of Evaporation (J/g)/Combustion Heat Energy (J/g)
                        Water: 2258/ N/A
                        Ethanol : 850 / 29,500
                        Methanol : 1100 / 23,130
                        Petrol : 310 / 44,100
                        Acetone : 525 / 29,500


                        You can see from this table that water is by far the most effective liquid to lower the air temperature - providing you can ensure that all of the water droplets are vaporised before entering the cylinders. If you were to perfect this system, the water would need to be atomised in some form of aerosol spray to maximise the cooling efficiency.

                        Methanol has a higher latent heat capacity than ethanol but a lower combustion heat release, and will vaporise marginally better than ethanol due to its slightly lower boiling point (64C compared to 78C).

                        I think the benefits you are noticing with the methanol come from the extra fuel effect as I doubt that the full vaporisation will be achieved with a garden sprinkler nozzle, although there is clearly some effect here. Maybe you could combine this with a less restrictive intake tract or add hyclones (I think they’re called) to enhance mixing with the air flow. (Pure speculation here).

                        I think you are on the right track as there are obvious benefits which have been recognised by spark ignition engine tuners for years. The fuel/air ratio for pure methanol is about 2.4 times higher than petrol and the latent heat of evaporation is 3.6 times higher. So pure methanol cools the incoming air nearly 9 times more than petrol (2.4 x 3.6). This is why methanol is the fuel of choice for high performance race cars, bikes, dragsters, monster trucks, etc.

                        Comment


                        • #13
                          Re: Water/alcohol injection and diesel engines

                          An engineer friend of mine seemed to think the water would react with the carbon in the combustion chamber to form either "water gas" or "coal gas", which is also flamable. Anyone know of this?
                          cheers<BR>Chris.<BR>1990 landcruiser 80, 1HD-T two tank, copper pipe HE+ 20 plate FPHE, toyota solenoids and filters. 1978 300D, elsbett one tank system.<BR>

                          Comment


                          • #14
                            Re: Water/alcohol injection and diesel engines

                            Water injection is great for petrol engines as it cools and slows the flame front on piston allowing you to advance the timing and getting more power as a result. With diesels, unless it works in the same way allowing you to advance your timing, I'd say the only benefit you'd get is the intercooling effect and the removal of carbon which would be minimal.

                            I looked at water injection for my Peugeot 504 I am building. It is a turbodiesel that I have rebuilt with 19.5:1 compression instead of the stock 21:1 and will use a boost controller to increase the boost from 9spi to around 14psi. As you compress the inlet charge more, it gets much hotter negating some of the benefits of the initial increase in boost hence the use of intercoolers on most modern turbos. The water injection would work well to cool the inlet charge but unlike petrol engines, diesels have no vacuum to draw the right amount of water into the intake dependent of engine load. The only way I could think of making this work on a diesel is to have a water reservoir that is pressurised from a T in the wastegate line so as the boost level rises, so too does the pressure in the tank and the volume of water being injected into the intake. In the end, I decided I would rather just put a large air to air intercooler on to be safe as I've spent way too much time and money on this car to use it as a guinae pig.

                            BTW, water gas is called steam
                            It takes a big man to cry... It takes an even bigger man to laugh at that man.:D

                            Comment


                            • #15
                              Re: Water/alcohol injection and diesel engines

                              A quick google on coal gas revealed this on Wikipedia:

                              Fuel gas for industrial use was made using producer gas technology. Producer gas is made by blowing air through an incandescent fuel bed (commonly coke or coal) in a gas producer. The reaction of fuel with insufficient air for total combustion produces CO: this reaction is exothermic and self sustaining. It was discovered that adding steam to the input air of a producer would increase the CV of the fuel gas by enriching it with CO and H2 produced by water gas reactions. Producer gas has a very low CV of 3.7 to 5.6 MJ/m3 (100-150 Btu/ft3 (std)); because the calorific gases CO/H2 are diluted with lots of inert nitrogen (from air) and CO2 (from combustion)
                              Town gas - Wikipedia, the free encyclopedia

                              I should think that the small amounts of carbon in the combustion chamber would be quickly consumed and be insignificant as an energy source for very long. This may be the reason that water cleans the combustion chamber though.

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