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Water injection.

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As some would know I have been a proponent of water injection for some years now.

Runing vehicles on veg oil, the big but hugely overstated fear is the engines coking up due to the veg not burning properly.

A while back the pump I use for the WI on my truck got rubbish in it and jammed. I was meaning to replace it but you know how things get. It was still running, out of sight, out of mind. Probably haven't had it going since the beggining of summer.

The other week my old girl started running rough and showing all the signs of dropping a cylinder. That neck snappin, eye rolling Torque only a historical NA 4.2 can give had well and truly faded, She was starting to blow more visable smoke than usual and with 565 KM on the clock, I thought the end of her days may be coming.

That said I also had in mind I had run a batch of oil substandard to what I would normaly have used.

Some things gave me a reminder of the failed WI pump and that the problem may be the engine getting clagged up.

The pump I run is the VDO windscreenwasher pump as fitted to commodores, BMW"s and some others. These pumps are capeable of well beyond their mere windscreen washer duties and have been tested over 24 hr periods of opeation with no loss of efficency. They are not however designed to pump grit or sand like I inadvertanly called upon mine to do.

Anyway, a trip up to the wreckers and $10 Later I had another pump and fitted it up. Past experience had proven very significant increases in performance both of engine output and cleaning ability of the Water injection through the addition of Metho. Methanol or ethanol also seem to work fine, Methanol is my prefrance.

Haveing sunk a hefty $10 into the guts of the system, the pump, I felt it only wise to keep the rest of the system standard on par and recovering a used 3L milk bottle from the recycle bin and washed it out, I had a fine water tank I could just squeeze in behind the left headlight. Again keeping to the system standard, used washer hose to a plastic garden irragation mist Nozzle I located through a small hole in the aircleaner lid right above the intake finished things off.

Being a manual gearbox. To switch the system I wired the pump to the positive side of the battery and used the accelerator pedal to switch the earth. This is done by putting a strip of aluminium can on the plastic stop under the accelerator pedal and riveting it with an eye connector back to the pump. I use the pedal itself which I tested as earthed to make the circuit for the pump ground. I just filed the back of the pedal a bit to remove the paint and make sure I had a clean electricaly conductive surface.

By putting a "U" shape bit of ally on the pedal stop, I can ajust the point at which the WI kicks in by bending the strip to the height I want. The strip will retain position even when it is squashed right down. Works just like a spring.

With everything working the next day I had to do some running round and made sure to kick the wi in wherever possible.

I could soon feel the difference the Water was making. The idle had smoothed out even about 10 KM from home with lots of hits of the water and clouds of black smoke coming out. At one point when I hit it hard through the gears I actually lost sight of the car behind me withthe dense black smog. I began to wonder If I would have a " how my 4.2 Grenaded " story to put up but it came good and I didn't get pulled over by the cops whichwas better still.

At one point along the freeway the engine started knocking quite loudly on 1 cylinder. Given the thing had plenty of revving out through the gears, I thought I may have broken something. It was OK under load but when crusing or at the lights, it was very loud. Wasn't too worried, what was done was done and I got the thing cheap so couldn't complain. I also wondered if the WI was syphoning with the constant draw of the intake on the freeway. Unlikely but of the nozzle was really dripping, it may be possible that some water was entering a cylinder in big drops that detonated in the cylinder.

After a while, the sound went away and I noticed that now when I revved the engine through the gears there was no noise or smoke at all. Usually there is some smoke as the pump is set high so I have no idea what it wasn't blowing some soot as It always does.

Time I got home and had exhausted the water , she was already a different engine. 2L of water, 1L of meth, 3 hours, maybe 80KM. I refilled the bottle and used that over another few days and the thing is now purring like a kitten.

The difference in engine sound is entirely different. I have also noticed the engine run on when I turn the thing off is waaaay less and it often shut down pretty clean now. I thought that was an I} solenoid issue but maybe not or only partially.

I have also noticed when I have gone to start it on some of the coldest mornings so far, it lights easily and dosen't chug on a non firing cylinder for a few minutes. The torque is back up and the driveability is much nicer.

Whatever it was the water cleaned out, it sure made a big difference.

I have seen this before when I first got this truck and on other diesels I have owned. You tell people water injection is great but sometimes you forget what a big difference it can make until you do something like this that creates a sudden change over what you get used to when you run it all the time.

Primarily my setup is to keep the engine clear of deposits from the veg oil. With the addition of Meth or ethanol there is a significant performance increase as well. I have also noticed that even when running water for a while on it's own, the car seems to run even better than with water alone after the meth mix is gone and you are back on water. I think the meth has some sort of extra cleaning power but have no logical idea or explaination for the physical actions that may take place over water alone as to why. I just know something happens and by the comments from my kids whom have no idea what I have been doing, it's something very clear in the way the car runs and sounds that isn't just wishful thinking or imagination on my part.

There is a train of thought that the water has to go into the engine as a virtual fog or vapor which I don't subscribe to on a diesel NA engine for cleaning purposes. Due to cavitation efect, I believe for cleaning purposes, getting droplets into the engine is actualy better than having all the water evaporated before it hits the cylinders.

For my wifes Turbo Diesel, I am still going to use the same relatively course spray nozzle and either inject post Turbo into the inter cooler, If I can find the right location I'll Inject post intercooler and until I have time to sort everytning properly I'm going to inject into the airbox onto the filter from the top. For the post turbo sites I'll use a 35-80 PSI Diaphram type pump as the VDO's will handle this pressure but I'm concerned about flow rate fall off bing too high.

Whatever fine spray is drawn into the intake from there I am confident will evaporate before it hits the turbo and the rest will definately be drawn as a vapor.

I'm thinking this system may hold merit in being able to inject more water over a longer time still using a simple on off system and without posing any danger to the turbo blades or the engine. In the cycle the engine is used where the thing may come onto significant boost at the top of one gear then much less to no boost after the change, by having the water delivery rate higher the engine may get to digest that water over a longer period than just a squirt down the neck at the end of the rev range.

Wether the evaporated water is as effective long term in cleaning as the shot of droplets straight into the manifold is something I am yet to try and make a judgement on. For the moment it's a cheap and cheerful way to get some water into the thing till I get a chance and the time to do other things. It may be that I see signs it's fine like that and leave it.

Anyway, IMHO water injection is the ducks guts for keeping engines ( and maybe exhausts) free of buldup and clag in diesel engines and even the most simple, rudimentary and cheap ass system can show significant and unmistakeable benifits and and improvements. It may have some benifit for the troublesome 3L engines as well.

Sure as hell couldn't hurt if it dosen't help. :)

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I've always maintained that what needs to be observed in order to keep the internals of a diesel clean and the engine running well are:

  • buy fuel from reputable sources, especially high volume turnover sources (other than if you make your own and know what you're getting)
  • do not do lots of short drives where the engine doesn't come up to operating temperature and unable to sustain operating temperature for a reasonable time
  • do not drive in such a way that you rarely load up the engine and make it work
  • do not drive in a way that you are, more often than not, in the lowest rev range, use the gears and rev the engine out
  • and more recently, use mineral-based, two-stroke, small engine oil at a ratio of 1:200 every fill (for 3.0lt owners)



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I agree Ray.

Unfortunately some of these things are not always achieveable. Even if you do follow the guidelines above deposits still may form.


have a merc engine here that has virtually no compression despite bing low mileage. It is the 2nd one I have seen coked up. These were on Veg oil but I think would have inevitable happened anyway.

In both cases the vehicles were driven in city traffic and sudsequently idled for long periods of time. There is little to no opportunity to rev the things out or load them up in peak hour. At best the standard shift points on Mercs are low anyway so unless one actually holds the gears or manualy selects L to get first instead of 2nd on take off, they are going to loaf along.

A couple of other makes I know are similar.

Now one might argue that these vehicles are not right for the job that They are being asked to do and I'd agree with that too. The thing is I have done sooo many things wrong with my vehicles and never had a problem thanks to the WI. I believe my recent experience showed that without WI these practices would like Bite me on the arse.

For one thing, I made 5 trips yesterday roughly 2 hours apart where on return, the engine in the patrol was barely up to temp.

They are unavoidable pretty much although short, the trips are too far for my wife or kids to walk to work and there is no efficent transport to where they were going. When the car takes under 5 min each way and public transport is easily up to an hour, Short trips are something that will happen.

I believe it is the use of the WI that allows me to do these less than desirable trips on a totally unsuitable fuel and get away with it.

I have also read numberous times that the ultimate failure for many diesels is actually ring coking ( even when running Diesel) rather than outright mechanical failure. As I firmly believe WI prevent sticking rings if used regularly, The life of many diesels may be extended significantly.

I don't have any proof of my beliefs, I have searched a lot for it but it does not seem people have done much along these lines with diesels. I'd love to have the time and money to do some documentd tests where I could strip and examine engines to do some documented testing on.

I'm not one for imagineing things and what I have seen so many times wth WI tells me it is of great benifit. For the sub $20 setupcost, I reckon it's worth everyone giving it a go! :)

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Don't get me wrong, I wasn't disagreeing with what you've experienced with water injection. Water injection has been used for just about ever in petrol engines, when modifications have been made to increase compression, timing etc. There is something that I studied quite a long way back about water injection in combustion processes, when I was doing engine mods, where the addition of atomised water made substantial improvements to the burn characteristics of all internal combustion engines. There's almost an encyclopedia that could cover air/fuel ratios, combustion temperatures, combustion pressures etc when it comes to playing with ICE.



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I find it pretty funny when you mention water injecion and like what you were talking about with the attitudes on some forums, someone has a shot at you saying it's stupid to put water in an engine and why do you think vehicles have water traps and all the other superlative ignorance they display.

Like you say, it's been done forever and in an amazing variety of engines from ships to aircraft.

I would like to find more on it in relation to diesels. Mainstram stuff is about power and controlling EGT's and the only cleaning refrences I can find relate to ships running bunker oil. They depend on it so much some have a sort of dual injector that fires water and fuel at the same time.

Still, I suppose if water will shift something akin to tar it's hard to argue it won't shift far more minor deposits....although plenty have. :P

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Well I think I gotta give this a crack.. Mines pushing 1/2 mill on the clock. I've just put a tank full of injector/engine clean threw it and I've noticed a bit of an increase..

This may increase it more..

A couple of questions though, what size spray tip did you use?? And did you measure a flow rate?


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A couple of questions though, what size spray tip did you use?? And did you measure a flow rate?


I use the Pope Brand Microjet Mist spray nozzles. Come in a Pkt of 10 I think for about 6-7 bux from bunnings.

The flow rate on the VDO pumps I use is around 250- 300Ml Minute. Depends how much washer hose you use. The flow rate is not critical as long as you don't go overboard and put the fire out. If the engine stumbles when the water kicks in you need to back it off. anything under that is good for long term cleaning purposes.

Contrary to what I have read on a lot of sites, you can pump a LOT of water into a diesl before yourisk any damage. A friend accidently pumped 1.5LITRES a minute into his navara and had water coming out the exhaust but the engine was fine. You couldn't flow that much water with a washer pump so I guess that's an inbuilt safety feature.

I have used this flow rate on Both my 3L mercs and the Mighty 4.2 and it seems pretty good for both. surprisingly in the testing I did, the 4.2 seems to have less capacity for the amount of water before stumbling than the 3L merc did.

If I can find the packet of nozzles I'll scan them and put them up but I have seen them everywhere that sells the home irrigation stuff.There are also ajustable nozzles but they are pretty useless. The ajustment is so touchy they seem to go from full open to full closed with about 5 thou turn.

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Zd 30 would be no trick. If you wanted to use my cheap and cheerful method you would spray onto the air filter or get the diagraph pump ( seen them advertised for $30) and go post turbo. Don't know if the garden nozzle would be near fine enough for safe pre turbo ( whether that is a real concern or not.)

A mate set one up post intercooler and I have seen on his temp gauge that the water drops the inlet temps 80oC and more.

The parts for the system would be a pump, hose nozzle and switch. As above for injection point on an SD t and pumps.

I have some boring pics of mine somewhere but they ae just the pump and the nozzle location. It really is too simple to go wrong.

That's how I managed to be able to set them Up! :P

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I find it pretty funny when you mention water injecion and like what you were talking about with the attitudes on some forums, .

Some people think that I'm retarded for running my two 3.0s on sump oil. 10000km and still rocking. Maybe i'm retarded and financially much better off. I am very interested in WI

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Do you do straight or blended mixes?

I have to admit Sump oil even though I have heard of it does seem a bit " out there" which is hypocritical seeing what I run my car on!

I was going to try sump oil but I didn't get far. Veg can be messy stuff to work with but Sump oil is on a whole other level from what I have seen. I try to be clean but still end up with spills and sump oil is difficult to clean up unless you can process it on a dirt or gravel area.

Sump oil to me seems even more prone to leaving deposits than veg oil so I think WI could be a good precautionary measure against any coking or buildup.

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I blend ATM because a lot of the oil I pick up is to thick to put through the injector pump. I have run a few lots straight but with winter here I would need to heat it in the vehicle and cant be bothered. Yes its M E S S Y. I wear old overalls with old clothes underneath and often throw the clothes out. I notice EGTs a little higher with sump and some serious smoke when I leave it idling but so far nothing has clogged up. I also run a good quality fuel system cleaner with most of my batches. I use the Patrol as a part time pilot/escort vehicle for oversize loads and figure that between my wife and I we have saved around $7000 in the last few months, so if my injector pump cacks its self tomorrow, we are still well infront.

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Yeah, that's an aspect a lot of people over look... "what if something breaks " Yeah well, I save enough for another engine every year and I'm 6 years into it now, so what? :P

You must be doing something right though. seems there is trouble with these engines running diesel. The fact you are successfully running a sump blend is impressive. How long and how many Km you done so far on it?

I'd be very interested to hear more about your setup and what you do. If you can run sump oil, no reason why these engines couldn't run Veg although I never percieved they could.

There was a guy I used to email in the states who was running an 80% WMO / petrol mix in an old ford PETROL engine.

Reckoned the only problem he had was fouling plugs every 6 months but used to clean them and put them back and they were good.

One day he decided to splurge and buy new plugs and found the ones he had been using were the wrong heat range. he decided to go a heat range hotter than standard and had been going 20 months when I last spoke to him and hadn't had the plug fouling problem since.

Sump oil can be very thick. The bit that would concern me more than the IP would be deposits in the engine and rings. If you burn sump oil say in a spoon over a buner flame, you get left with a lot of crusty deposits and ask. You get some with veg too but in my mucking around, there is a lot more in sump oil. I think this is where WI would have the most potential benifit for you... Removing any left behind coking and hopefully eliminating any chance of stuck rings.

I think If I was forced to use something different to veg the one I'd try would be Used tranny oil. Much thinner than WMO and I think it would be cleaner to handle. From what I have reaqd the viscosity doesn't change as much as Veg or sump oil when heated.

There is a big transmission place up the road from me and every time I'm stuck in the traffic out front I think to myself, " I must go inn there one day and see If I can get some used fluid and have a play with it" but then I forget about it till the next time I'm sitting out the front stuck in traffic again.

It would be interesting to run some viscosity tests on the tranny fluid and see how it compares to veg.

Have you ever looked into cracking the sump oil and turning it back into diesel or petrol? There is a lot on the net about it and it's easy enough to do.

Basicaly you boil the stuff, superheat the vapors and then re-condense them. If you do the process without the superheating you get a lighter fractioned oil. the superheating brings it back to diesel or petrol.

I have been playing with cracking Veg oil. I can get a very light product out of it that is nearly flameable from it's own vapor like petrol but not Quite. I'm sure I could get a petrol substitute if I condensed it at the right temp.

Seems like a much easier and simpler way to get a more diesel like product from veg than doing the bio process. Would be a hell of a lot cheaper as well.

Apparently plastic also also cracks down nicely to petrol or diesel being that the stuff is made from oil.

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I did look into cracking and got a mental picture of me getting fried and a crater where my shed used to be.

WTF is hard to come by around here, I live in a rural area and most of the oil I get is diesel. I run it through this http://pabiodieselsupply.com/shop/waste-oil-centrifuge-65gphb-p-298.html. I run a 44 gal drum with no top and leave the fuge running for 24 hours or so. That way everything goes through the filters around 30 times. I either blend with 20% petrol or 50% diesel. The overflow from the fuge runs into a 1 micron bag filter to make sure I get everything I can out of it. I then leave it to sit for a few days and drain the thickest crap off of the bottom (usually around 20 liters). It then goes into my storage tank that once saw service as a home oil heating tank. My vids are here http://www.youtube.com/user/adrenalize666?feature=results_main.

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WOW, Small world.

I have watched a few of your vids before.

You certainly have a great setup for someone who's " Not an expert".

Those Fuges sure have come down in price. They are made in my postcode but it was still cheaper for me to buy from the states than what they would sell them to me for. I might look at getting one now. Not sure though.

I set one up a mate bought for doing his Bio. Spun up some of my oil and the amount of material it removed was too small to bother with really. It was also the mega fine stuff that you could only see in a clumps and I was quite confident would pass right through the fuel system anyway. Even if it didn't, it would take a lot of oil to block a filter which is what I basicaly experience.

Given the reduced prices of the fuges, They may be worth another look. My current system does a great and perfectly adequate job but fuges are the holy grail of filtering.

Do you get much out of the fuge that the Filter bag leaves behind?

If you have the ability to do so, the longer you leave the oil settle the better. I have about 5-6000L in storage of any time mainly in IBC's and try to use the oldest. The longer you leave it, the more crap drops out and the less cleaning you have to do. It's the perfect lazy mans sport!

I use the same filter bags you do atm and if I don't get 2000L through a 1Um bag before it slows down, I have done something wrong.

When I got the oil and filtered it straight away, I could clog a bag in 400L. Pre settling makes a HUGE difference.

You may also find that if you get the oil and put it on your burner and heat it then let it settle and pump off the top, the heating will thin the oil and speed up the settling process.

Yesterday I was setting up a keg to run the oil through to heat it up. I have a burner of a similar design to yours and another I built through the week which I'll use on the veg heater. I need to up the production rate again and heating the veg makes it dry much more quickly and filter easier as well.

Like you I process in a 44. what I want to do is take off from the pump I use and push oil through the keg which will be sitting over the burner thats punching out about 100Kw and circulate it through to warm it up. This will also give me another 50l capacity per batch.

Maybe I should hook in another 44 and double my capacity? Now I have myself thinking!

Are you adding in the petrol before you run the oil in the fuge?

You will loose a lot doing it that way as the fuge will evaporate it. You would be better to heat it for thinning then add the petrol after. You'd want to leave a door open in your shed when you are running the fuge with the oil petrol blend or the floor of your shed could look like a launch site.

Speaking of which, with cracking the oil, it's perfectly safe. If you use a drum / retort / tank which has only one outlet and no way of oxygen getting back in, it cannot explode. That's how modern car fuel pumps run the petrol right through the motor brushes.

I run the vapor through a transmission cooler as a condensor and the output bubbles up through water.

This condenses all the vapors, provides airlock and gives a visual indication of the vapor being produced.

The product floats on the water and drains off the top into another container. As the water and fuel won't mix, it's easy to seperate the 2. That said, I'm also thinking of using cleaned Veg instead of the water so I have no contamination at all and a fluid with a higher working temp.

Given your oil is from diesel engines, there would be plenty of the lighter fractions to draw off if you did crack it.

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I get a very fine, rock hard, sticky .........Stuff???? (for want of a better word) out of the fuge that I have to scrape out with a screw driver. Even after it has been through the bag filter 20 or 30 times

I also ran a two drum set up for a while with a dropper between the drums, to help the heavy stuff fall to the bottom of an old gas bottle. It didn't seem to get any more sludge out and I couldn't stop the c**t of a thing from leaking. So the single drum setup is back in action again.

I saw some of those white 1000 liter tote things for sale the other week for $50. I want to mount one in my trailer for picking up oil and one in my yard to settle the mix.

I add the petrol before I run the mix through the fuge. I found that my power bill jumped a fair bit when I heated the oil with the band heater and don't trust my oil heater under the drum. Heating the oil didn't seem to remove as much sludge as petrol either. So I pretty much gave the heating away. Settling is the best for removing crap, especially with the petrol added. The fuge seems to create very little heat and makes no difference to the oil temp. Why do you say it might explode?

Most of my oil comes from local transport company's and I have been surprised how little water I have got from the drums I pick up. If you are after some oil I spotted about 7000 liters the other day and it's been sitting for years, so it will be nicely settled. The only prob is that its about 100km away with a mountain range in between. I need to fit brakes to my trailer and get it registered before I can go get it :-{

I might look into cracking some more as the Patrol may well end up being my main pilot car for a while with a D22 Navara as back up. I will need a reliable brew that is not costing me $1.55pl. Diesel was $2.20 at Innaminka a few weeks ago FFS. Lucky I didnt have to buy any :-)

I will have a look at the WI vid now

Edited by Bogmeister
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A water injection thread turned into a veg & blackdiesel discussion. I'm wondering who you talk to Glort seeing as these people think your veg and WI adventures are radical or "out there"? I think you would be surprised how many of us there are that do both. And we dont all follow convention or recipe. And we dont think your crazy :D

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Holy crap x 2. That's awesome. I would like some torque below 2000rpm but I would be happy with just a clean motor. How much is meth and where do i get some?

The blokes in the video do kits retail on eBay for $400-$600 depending on what stage you get..

But I've been looking for atomizing tips.. It's a bit hard finding them for less than 500 psi.. But did find this one site and this tip..


I think the old commodore water pump might not cut it.. But for $10 I'm going to give it a crack..

Next is to get a descent tank..

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