Water/ propane injection of wvo fueled listeroids

[skeeter]

Since decarbonizing my 12/2, I've been giving some thought into additional ways I could be minimizing carbon buildup, as part of a routine operating procedure. At this point, I think I'm doing about all I can to minimize buildup without doing something completely different.  I'm starting and stopping on diesel, have well heated fuel lines, and running wvo only when up to t-stat temp(195 deg. F). Maybe I'm wrong, but I'm starting to get an inkling, that running wvo, will over time, substantailly add to my maintenance effort,  if I want to maintain it at peek operating efficiency.  I'm starting to think that implementation of an on-demand propane or water injection system, might be a reasonable course to pursue, if I want to reduce the need for decarbonization, and keep the listeroid running longer near its peak efficiency, between decarbonizations. Does anyone here have experience with either of these? Have search here and elsewhere. I do find how it relates to performance, but not allot of qualitative data about controlling carbon buildup. Also, what's everyone's experience with decarbonization requirement for listeroids running on diesel or bio-diesel.

[mike90045]

My expierence with water inkection has been on gasoline engines, and with substantial air flow, which took the water stream from a "windshield washer nozzle" and broke it into a mist.  With the low flows of the listers - I would expect to see puddles of water forming, and the posibility of hydro-lock. 

Or I'm all wrong.     No experience with propane  (as engine fuel).

[phaedrus]

I too looked into the propane business and water too. I have not yet experimented with it in a diesel - I did extensive tests with water injection in volkswagon engines years ago. Little carries over. I was able to run 11:1 pistons on regular gas flat out and in city driving - the test bed was a very modified (isky cam specified for the aplication, 1800 cc cylinders, header exhaust and intake, electronic ignition, and so on) "late model" (crossdrilled crank) 40 hp engine in a '62 hippy bus with '67 reduction gears (taller). The bus was scary fast! I never learned how fast, but I got it close to 100 and chickened out. Clocked about 50 thousand miles with the only real problem being icing - and that was managable by adding a bit of oil to the gasoline - the ice formed, but didn't stick if there was a bit of oil. Clearly I was nuts.

For the Lister type what I settled on as a logical approach was evaporating the water well outside the engine, ie feeding air at close to saturation, not mist. Placing the evap below the engine prevents any possiblity of water entering the engine. In compression the vapor ought to condense into a fog very briefly, then change back to a gas, this ought to reduce the energy requirements of this phase of operation slightly. Keeping the evap-air flow insulated ought to slightly improve volumetric effeciency a bit too. What effect it might have on coking is unknown and I have no idea how to predict - but it probably won't hurt.

Propane flow, as a gas of course, it is said, ought not to exceed 10% of the BTU of the diesel fuel flow. I decided that proportioning the gas input to the diesel input, while do-able, was probably unnecessary, unless you have very cheap propane and 'spensive diesel. It looked to me like a simple gas-feed that was interlocked to make sure no gas fed unless the motor was running, and manually calibrated to have a feed rate just below the point where the engine begins to run rough and tells you to stop, would be enough to minimize coking. Of course the engine would be running unloaded when you set the valve.

The propane trick especially are on the "to do" list around here. The prefered fuel here is cleaned up lube oil. Pretty thick for the l'oid. Coking's an issue here.

Keep us up to date with what you learn, eh?  Best, P

[Tom]

skeeter,

What kind of loading are you running on your 12/2? Also how many hours between decarboning and how can you tell it needs it?

I'm currently running running my 6/1 on a 50/50 mix of bio/wvo unheated. I've got about 200 hours on that mix and no problems so far.

[craig c]

Hi , Raise your compression up to 18 to 1 and you will have more combustion temp to burn the fuel , carbon is only unburnt fuel and your engine will run a lot better , check out this web site ,  www.veglisteroidnz.co.nz   thanks .

[peterako]

Hi there carbon is a problem based on low engine temp. or a bad injection mist/time , also to load changing is creating a a carbon problem. Or check your balance from your twin ( push pulling here can be a problem ) checking the exhaust temp and loading the engine  will help here.

checking for propane or water injection will not help if there is a technical problem.

I have seen here in Greece 6/1 running for water pumping original without that the head is removed and running every summer every day.

Greetings from Greece

[skeeter]

My 12/2 in summer months, runs 5 - 7 hour per day. Load during 2/3 - 3/4 of its run is typically between 75 and 80% (42 - 45 amps, 115 vac). During last 1/3 (battery charge tapering), load reducers, although I do add on other loads such as pool pump, wash machine, and dishwasher, to reduce this taper. I rarely ever allow its load to reduce below 40%. Regarding spray pattern, I'm heatiing fuel to 225 deg. F to reduce viscosity to close to diesel. Regarding engine compression, previous to last decoking, I definitely felt compression was too low. During first 600 hour of service, head clearance was at .068", which I reduced from .080" (I don't know what they were measuring at the factory). At the time of last decoking, I further reduced clearance to .055 - .056". I never actually measured the compression with a volumemetric measurement, but I can say after this reduction in clearance, compression felt much higher. Cylinder exhaust temps are within 20 deg. F at 80% load. I have yet been able to get them any closer. I must say, since I lowered clearance, it seems to be running much cleaner. Fuel consumption is lower now. Overall, it is running much better. Also noticed valve adjustment is now holding steady so far, without need to readjust. Before it required valve clearance to be readjusted more then seemed reasonable. I suspect this was due to continuing buildup on the valve seats. It is now about 150 hours running since I decoke, it still seem to be running very good, but I'm starting to "sense" a slight change in sound (not mechanical). Maybe I'm crazy, or just listening to it too often. I don't know. What decoking interval is everyone else adapting, and what fuel are you using.

[dkwflight]

Hi When you have the engine running hot enough ang broke in well then you can try some other things.
Another web site is recommending running some pure acetone in the fuel. on the order of 1oz per 5 gallons of fuel. Its worth a try. The claim is better combustion and soot reduction.
Dennis

[gpkull]

it is recommend every 1000 hrs dismantle decarb and grind valves. ya right it aint broke dont fix it. veggie only makes it worse. a steam inj would not vapor lock and keep everything kleen.  if u ever saw a blowed head gasket syndrom you see a piston or too spit shined the rest just carboned up this is gassie motors. havent done it yet but my steam cleaner is next to volunteer. there is a guy calling his motor a 5 cycle. the way i took it is after 1 thru4  it squirted a blast while the hot gasses were still contained and the expansion rate of h20 was so great there is  a gain from this . the major benne was less fuel for the same work

[biobill]

  Skeeter,
    Haven't heard any negatives about the acetone. Guy's checking fuel consumption report modest or no gains. My understanding is that it's supposed to decrease surface tension so you get finer atomization. Might be a good thing in your case. Cheap enough to try anyhow.
  Just pulled the head on a 6/1 with roughly 600 hrs. Carbon was not an issue. I'd feel comfortable going twice that. Engine runs mostly at 1/2- 3/4 load and burns homebrew biodiesel with no ASTM influences
                                                   Bill

[skeeter]

Acetone, if it works, is alot easier then anything I've been contemplating. I'm going to definitely research this further. If it looks promising, I'll try it.

[mike90045]

about getting engines really heated up, are the 195F thermostats, as hot as they go?  With a little antifreeze/coolant, could a 210F be installed ?    When I get mine, maybe I'll try a spray bottle of water at the intake for a minute, just before shutdown, while things are really warmed up.
  Anyone use coolant - or all these all on straight water ?

[skeeter]

I use a 50/50 mix of coolant and water with 195 deg t-stats. Never thought of going higher then that.

[skeeter]

Since my last post with 50 hr more run time (200 hr post decoke), what was then a faint change in sound, became more noticeable. Sound coming from crankside cylinder and definitely sounded more mechanical, llike excess valve clearance.  I suspect, for whatever reason, this cylinder tends to coke up quicker, causing excess valve clearance due to buildup on value seat(s). I didn't actually measured it yet, but I'm pretty sure I know the sound. Also noticed cylinder was becoming a little harder to start. Instead of popping on first compression stroke, it started firing on the third or more, and exhaust temps for this cylinder seemed to have dropped a little (other cylinder temp bumped up a little). Compression also felt reduced for crankside cylinder. Since my last post, I read up on others results of adding acetone. Not the long term cure, but promising for my case.

Yesterday, was the first run with the additive (1 oz. acetone/ 5 gals wvo). I decided to leave the valve clearance adjustment alone for now, believing that if the addition of acetone has a cleaning effect, I would soon notice a reduction in valve noise, as the carbon is removed from the seats. After the first days run, "valve noise" is still apparant, and cylinder temp may have picked up a little. When feeling the cylinders compression by hand pushing through compression stroke, I believe compression has increased some. Today, when starting, cylinder popped on first compression stroke, and after just checking (3 hours into todays run), valve noise may be reducing slightly. I guess at this point, I'm going to continue what I'm doing, unless someone has a good reason why I shouldn't. I'll post as thing play out.

[gpkull]

is yuor heated fuel at 225f going into the ip and thats it? there are line heaters that bring wvo up on temp after the ip. the  more viscus the juice the more effeicent it will burn. youcan bring your veggie so far up between the ip and inj so long as it doesnt cook in the line. the hotter the better.  also you can bring up temps by reverse cooling. your engine runs better as it gets hotter.