Got a question, George. I have heard some guys speak of ring coking. Is this a problem with WVO and, if it were to happen, how would one alleviate the problem, sans a tear down and good cleaning, rebuild?
Ring coking is the perpetuated and grossly overblown fear of the Veg/ waste oil world.
People crap on about it chapter and verse but the actual instances of it happening are far and few between and then even those are repeated.
As I pointed out on a forum nay years ago, tell me if you have first hand actual knowledge of an engine suffering ring Coking. Not your mates coworkers brother inlaws uncles panel beater, But you yourself or a mate you know well.
In a forum of several hundred people logging on a day ( this was back when veg was all the rage) the only person that had seen it was me. I helped a friend pull the old clapped out engine from his merc wagon and the thing hadn't even got to run on oil yet. It was just it was buggered and as well known, they will coke up on diesel as the last stage of their demise.
I then did a quick count of the posts about ring coking that month and found about 12 separate threads of worry and concern on it and about 100 grim and dire warnings if you didn't follow the prescribed, socially approved parroted mantra.
Yeah it happens, no question but for every case it dose there are probably about 10000 worry wart posts and fears about it. I have only seen or heard it happen because of other pre existing problems.
Case closed from my POV.
Let me just put my future statements in perspective and where I'm coming from with them because they disagree with about 95% of the approved and parroted Veg oil mantra.
My first veg car was an old merc I didn't actually want to buy but my wife talked me into that particular car. I wanted a merc but this one was not in good shape so I didn't want THAT merc. Didn't get it 10 KM from the seller and it broke down and had to be brought home on a trailer.
In hindsight, best think that could have happened. I learnt so much on that old thing and I would blow my own trumpet as saying I am up there with the most knowledgeable people in the world on veg. Egotistical, of course, but there is a real good reason I say that.
Most people try NOT to break their car.
I was the complete opposite.
I didn't think the thing would last till the rego ran out and therefore I was interested to see what would kill it. I tried all the fabled fears and problems and found about 95% of them are pure and utter bunk. The rest are so unlikely not to matter or can only come about through neglect or stupidity.
And thats the other thing right there. I TESTED these ideas. Unlike pretty much everyone else, I didn't just copy the guy before who copied the guy before him who lived in another part of the world who did what the guy before him did etc and no one ever thinking WHY they were doing something, IF they needed to do it or what their particular situation was.
I got my hands dirty and when someone said this will kill your engine, I ran out and tried it instead of avoiding it. I researched things not just only in the veg world but looked at other industries and applications and what they did. In that alone I found endless bunk and misinformation that other people and industries defie every single day. Not in using veg oil per se but in the theories and practices veg oilers held.
One of those things was was preheating the Oil ( fuel) where people would use 2 or even 3 30 plate or larger heat exchangers. From working with a mate on pool heating, I knew by the look of the things they had to be waaay overkill on one let alone multiple. I looked up the data sheets and got a sales rep to crunch the numbers as far as fuel flow, specific heat density of oil and water, etc and the rated output of the HE itself. I found the things were about 50X overkill for the fuel volume required and it was a joke using one 30 plate when 5 plate would do let alone using 2x 30 plates.
There are endless things like that people do without thought or question because that's what they are told and they never question if THEY need to do it or why anyone does it in teh first place or what problem they are trying to solve or over come. They follow blindly and that's it.... till their over complicated setups fail and then they try to complicate them more to offset the wrong problem.
Turned out I got to love that car, fixed it up and it was a part of our family like a loved pet. I called it Helga and people would ask me how he wife, kids and Helga were when I saw them. Had it for 3.l5 years till, like Bruces example, I went to pull the thing off the road to give it a complete restoration and wasn't an hour into it before I found so much structual rust restoration would be completely impractical. Pulled the engine which I still have and sold it to an arab guy who put it in a container and sent it back to the middle east to be used as a Taxi. Told him about the rust which he said he would fix but I strongly suspect that "fix" would involve nothing more than kilos of plastic putty and maybe some under body sealer.... or just spray paint.
From that hands on testing experience and knowledge I hold myself out as having more hands on, real world, tested and Documented experience than all but a very few people out there. I have proven over and over that so much of the common veg practice is not only unnecessary but the reason behind so many ideas and practices does not add up with physics or logic.
So, coming from that self centred attitude, heres my thoughts and more so experiences.... :0)
The whole pre heating the oil thing with oil is a real big parroted fear amoungst most oilers. It also for the most part is complete and utter bunk.
If you look at the two most suitable types of IP to use with Veg, the inline and rotary style pumps ( or plunger type on small engines) and look up their viscosity tolerance as set by the manufacturers, it covers pretty much any oil you could reasonably pump down a fuel line. The inline pumps like on mercs will pump lightly gelled liquid fats with no problem. Warming the oil to thin it so the IP can handle it and the injectors can spray it properly does not add up. It's that simple. The greatest reduction in oil viscosity is from 0-40oC from 40-80 as most people prescribe, the reduction is only a few centistrokes or a fraction of the 0-40 reduction. Also pressure does NOT affect injector spray pattern. With conventional injectors, the pressure must be reached before they pop off, if it's not they won't pop and the engine won't run. Therefore viscosity of the oil as long as the IP can handle it, which it can if the oil is liquid, is irrelevant.
And that's when the engine is cold. Soon as it heats up, the injector which is embedded in the hottest part of the engine, the head, has a huge amount of heat transfer from the head and being exposed to the combustion chamber. To assume that the milliliters of oil that pass though an injector in a minute ( had the numbers once but forgot now but very small) would be sufficient to cool that injector or indeed have much effect on its temp at all does just not add up or gel with principals of thermo dynamics. It makes ZERO difference to the spray pattern because the injector must exceede its pre set pressure to pop off and if it does, the spray pattern is the same.
The REAL cause of ring coking I believe is something no one ever realises.
I believe ( and have demonstrated) it is almost entirely ( in a healthy engine) dependent on the Injector pump fueling setting and to a lesser degree, pump timing.
If you get a tablespoon of Diesel, kero, petrol, biodiesel , turps etc and put it over a blow lamp till it all burns away you are left with nothing. Do the same with oil, veg/ engine, tranny fluid etc, you get a deposit. Mostly that takes multiple stages. At first it burns to a sticky tar. Keep the heat up and it turns to carbon like charcoal and then it turns to ash like wood ash. You can easy do this test yourself like I have to see.
If the engine is fueled so there is enough air to burn all the oil, I can only assume the oil is burnt to ash and exhausted. If it is below that, then it is likely to remain, in part at least, in the cylinder and will be scraped from the walls and end up in the ring lands. Because this is a cooler area in the piston and often has holes behind where oil may be admitted through the rings to the cylinder, the tar and carbon build up. there is very little area for the flame front to burn these deposits off like they could on the piston crown, valve faces etc.
When a diesel engine smokes under load on Diesel, the carbon is just blown out because diesel burns clean. When a diesel Smokes on oil, it's most likley leaving deposits. That's OK unless those deposits are excessive or there is something else at play like too much oil coming in the form of EGR bypass, bad rings, worn valve guides etc but I'll assume an engine in good condition for the sake of yet another long winded post.
Now if the smoking of the exhaust is short lived like just under heavy acceleration and the fueling of the engine is set at factory levels, for the most part one would be fine. May be different if you do a lot of hill climbing at full throttle etc but for regular driving, I believe these deposits are light enough to be burned away over the much greater period the engine is running lean with excess air as diesels usually do cruising along.
If one turns the Fuel right up like I have on my Turbo Diesel Peugeot I had so the thing will spin the tyres in first gear rolling along with the clutch fully out, then the smoking is much heavier and longer lasting meaning the engine is getting a lot of buildup. If you touch the throttle and the thing starts smoking, you are in for a short engine life... unless you offset the problem.
If the timing of the pump as become out, particularly late, this is also detrimental to coking. Ideally you should set the pump about 5o sooner than normal because oils burn slower than diesel and therefore need more time in the cycle to light off and reach peak Cylinder pressure. Late timing means the charge does not have enough time to burn and the fire well may go out before the combustion is complete which results in the tar deposits.
Again, on a normally tuned IP under normal driving conditions, IE no unusually long periods of wide open throttle, I'd say the chances of ring coking on veg or WMO are the least of your worries and behind getting taken out by a drunk driver. Just NOT going to happen.
But what if it does? What if like me you turn the wick up too far or you DO tow up a mountain every day?
There are a whole load of fuel additives and cleaners you can use. And you will waste your money on each and every one of them. Physics and understanding of how engines work will tell you, they can't. There is nothing out there that is actually designed for this problem. Might say it is but they sure as hell never had veg oil in mind! :0)
There is a solution. Its cheap, simple, easy and that's probably why most people won't take it seriously. I have noticed, and sorry to all it offends, Americans particularly have this disposition that unless something is expensive, complicated, has loads of parts and therefore failure points and big numbers, it can't possibly work.
Well in this case it absolutely does.
And Im not talking some $600-1200 commercial system here that sprays the water to a fog finer than found in a rain cloud, I'm talking something that just kinda sprays the dam water in to the inlet and that's it. The airflow and heat in the cylinders will do the rest. I believe in fact that rather than having the water vaporise before it gets in the cylinders, for the purpose of cleaning its far better to have the water enter in droplets.
I researched this when people told me that the phase change from a liquid to a gas caused tiny explosions called cavitation. I knew of that in marine terms but I looked it up and that's what happens. In a cylinder the pressure raises the boiling point of the water droplets until it reaches a critical level where it actually explodes to vapor. Now these micro explosions are not significant enough to cause erosion of ANY metal let alone the alloys of aluminum used in pistons or the heads or steel more commonly used in diesel engines.
It is, wonderfully, conveniently strong enough to remove carbon or tar deposits which is what we are dealing with.
Basically the water steam cleans your engine by blasting off the deposits and because it is so fine and not burnt like many believe, it can permeate all parts of the Cylinder including the ring lands.
You can set up a WI system to run heavy for cleaning and then when the engine is clean, and you will be in no doubt when that happens, you can back the water off. You don't have to, you can run the water heavy all the time. just means you'll be filling your tank more, a LOT more.
In the case of the Pug, I ran the water at a rate of 300Ml a minute which is my almost universal dose rate. This was a 2L engine and I ran it pre turbo... which I would not do or recommend but I was still learning and that is what I did. I believe it took the edge off the tips of the compressor blade and made the turbo develop less boost at lower RPM causing the boost to come in later.
My WI setup at first was to use the windscreen washer pump and bottle to squirt through a Micro mist home irrigation nozzle. Mist is a relative term on these, they are a coarse spray in fact which is actually what we want.
The pump was triggered through a Hobbs/ pressure switch set to activate at 3 pounds boost.
And that was it. I filled the bottle daily and then went to a Diaphragm type pump I bought off ebay and a 5l oil container that I squeezed under the bonnet . Still filled it every day pretty much but at least I got a lot more water through the engine.
If you want to clear a bunged up engine fast, set the thing running to about 2500 RPM and pour water straight down the intake. take the turbo pipe off if you have to. It won't be boosting under no load anyway. Pour the water in just fast enough so the revs don't drop or drop slightly. If they start to fall off, ease up on the water. You'll be amazed how much you can pour in there. A liter a minute is easy.
DO NOT park the car with the arse end facing your wifes petunia patch, your garage door or a house wall, the freshly painted white Pickett fence or anything you don't want sprayed and dripping with a black sticky gunge. Shits gunna fly everywhere and it's near impossible to really get off. Not just from the engine but from the crap buildup in teh exhaust which I believe is something regular WI also cleans and keeps the gas flow up resulting in better performance.
I inject 300Ml a min on my 4.2 L engine as a normal dose rate. People that see the benifits of WI tend to get carried away with it and want to run water when ever the engine is running and pump the stuff though like no tomorrow. That's a mistake and unnecessary. You only need enough to prevent any buildup and that takes weeks if not longer on an over fueled engine. It's not going to happen at all on a normal fuel rate so it is a preventative rather than an absolute need like engine oil in the sump. I have my engine over fueled for performance and I also like the performance increase the water gives.
On my old merc, just plain water alone reduced the 0-60 KMH (0-35? MPH) time by 3/4 of a second. May not sound much but ask Bruce what a difference that is a non turbo merc. Means it gets to 60K probably more than 100 m of roadway sooner. With meth added to the water, the time taken from many runs over different times and conditions averaged at a fraction under 2 sec faster. In that car, that is a HUGE boost in performance.
Remember, That was 60 KMH not MPH. I couldn't find a quite straight road long enough anywhere near me to do the 0-100KMH (60 MPH test).
I asked a place that had a 4KM bit of road but international airport operators aren't very co operative when it comes to letting old shitboxes on their runways after kerfew I found :0
On the current truck, the meth makes the thing too fast for it's brakes and handling really. On a section of the highway I regularly travel up the steepest, longest hill around, I purposefully slow as much as I can at the bottom and then floor it as It starts to climb in top gear. By the top I am well over the limit and have to back out of the throttle because the engine is still pulling but I'm starting to over rev and have no more gears left. Thing pulls like a train and I have upset more than one driver of much newer and supposedly more powerful trucks. Still a slug on takeoff with it's weight but at highway roll on speeds, the thing eats hills for breakfast.
I found adding Methanol/ ethanol to the water at up to 50% not only gave a performance boost but also aided in the cleaning process. I have not come up with a reason as to why that is. Even when I am running the WI on my engines that I know are clean through constant use and with the ip turned well down, If I run some meth for the fun of the shove in the back it gives, the engine still has more pep even when the reserve is refilled with water and the tank is half or more used. I haven't been able to figure that one out yet. Eventually performance comes back to normal but it is better even after the meth is well gone. I can't see the the engine is extra clean to the point of better performance otherwise the engine would continue to decrease till it logically stopped. I wonder if it might have to do with the exhaust being clearer and allowing a better gas flow? I have seen the phenomena 100 times, haven't come up with a reason I'm convinced of to explain it yet.
My current vehicle has a 25L water tank in the back and is fed buy the same Diaphragm type pump. I use no nozzle at all now, the water goes into the manifold through a compression fitting which holds the 1/4" copper pipe which is a little flattened on the end. That is it. No mega pressure pumps, no microfine spray, it goes into the manifold as a wide thin stream and that is it. It'[s something I have trouble getting though to people. They won't belive there is no nozzle or spray jet or whatever. The airstream breaks the water into fine droplets as does hitting the manifold walls, the valves, pre chamber etc.
The current pump is dual triggered. Firstly through a pressure switch which is set at 4 lbs of boost and a plate on the throttle stop which makes the throttle pedal itself act like a switch on the ground side of the circuit.
The reason for the pedal switch was firstly I devised it for my non turbo truck I couldn't use a boost signal from.
Secondly, when using Meth in the WI, I can flatten the pedal and get the meth in the engine at any RPM or boost level which brings it on to boost quicker particularly for roll on acceleration without having to pull back a gear if the engine isn't at boost speed already. I have used that in winter to give a shot of meth into the engine for a cold start particularly if I was a bit shy on the glow plugs and am running straight oil with no added petrol . Makes the thing fire much easier.
The whole thing with the WI is it does NOT have to inject a fine mist like all the WI kit makers will rave on about. A fine mist has some benefits at cooling the inlet charge for performance purposes but I'd guarantee its more to do with big numbers, sounding more impressive than actually making a difference to the engine above a point way lower than they exceed.
On my stationary engines I just drip the water through a hypodermic needle as the metering device into the inlet port. The hypo is very convenient, just to stick through the rubber or plastic flange of the filet mounting or the priming port that my china diesels all have. My Internet mate in south africa that run his homestead and business from his Lister generated power also is using WI and stoked with the difference. His hard worked engines running the thick sump gunk he gets needed frequent de coking and suffered declining performance well before that. A run on diesel would help but was obviously costly and the benefit short lived. His Wi system is manually activated and just gives a heavy dose of water at the end of each run. He uses enough water just so the engine does not stumble but will chuff out some water and chunks of carbon. it seems to be keeping the engines running fine and when they do start to bog down sometimes during a 16 hour average run, he hits the WI again for a while and they come back up to full noise.
He has just rebuilt one of the engines after an insane amount of hours work on it and bumped the compression ratio and spent a lot of time fiddling with and checking the results of changing the pump timing.
I would not run an oil fueled diesel vehicle without WI myself. Everyone I know that has tried it even if they are running bio has seen the difference it makes and run it from there on.
There are as many misnomers about WI as veg oil, one of them being that it will increase fuel economy and if you go too much on the water it ill hydro lock the piston and destroy the engine.
WI will NOT increase mileage. If it is properly set up it will in fact decrease it by an amount less than driving habits however it will be a decrease none the less.
As for Hydrolocking, another thing you'd have to put serious effort into getting it to happen. I have had a friend run 2L a minute through his 2L diesel and apart from blowing clouds of steam, had water running out the tail pipe and being undriveable, the thing was completely fine. Corrected his mistake with the water delivery and no more problems. the thing just continued to get better for a couple of months till it plateued out ovbviously clean and stayed at that improved level.
I have an old Toyota diesel engine and am thinking about doing something to run my portable sawmill. Diesel here is around $1.40/litre. Also thinking about wood gas. Got a lot of trees that will produce a lot of waste just from the tops, let alone the side slabs.
No experience with wood gas but done plenty of reading on it.
My Impression is it's a LOT of work and infinitely harder on your engine than liquid fuels. The learning curve also seems a lot steeper than with oil. Unless you scrub the gas very well and get all the ash out which I don't think you ever can, the engine will wear very quick. Something like a saw mill that does limited hours, might last 20 years so no problem.
The distinct Impression if get is that Oil is loads easier to use with instant startups and shutdowns and a lot easier to run an engine on it.
If you can get oil I'd suggest it would be the far easier way to go, If you can't get it or enough, then use the resources you have and do whatever you need to setup and make use of them. :0)