WI on IDI 1.9 Turbo Diesel

[nutron]

I wrote alot there but I still missed something. I ran 100% methnaol on mine for a time and it made ALOT more power with no related problems that I know of. I have no idea what the EGTs were while running that mix though, so I would not suggest that others do said. The boost on mine runs as high as 30psi also.

[IDI]

Originally Posted by nutron

One thing I am interested by is the knock, as the auto ignition point of methanol is significantly higher than that of diesel (diesel = 210 C, methanol = 470 C). So in order for the methanol to be pre-igniting, you would have to have unthinkably high cylinder pressures, that would without a doubt be giving massive rises in EGTs if the engine was actually capable of withstanding them (which I find implausable at best). So I think you need to look to a different reason for this knocking sound, which may well be the methanol but not as you think. The specific heat capacity of water of massive, that's why we use it for cooling, fighting fires, e.c.t. Methanol however isn't as good and as though it would cool the intake charge, on it's own it could expand and create higher cylinder pressures and temps (this is only a theory). If you have a non-dirrect diesel injection with a pre-ignition chamber, the diesel might be igniting at the wrong point, or it might be igniting, and creating a sufficiently high temp to then ignite the methanol in the cylinder before the flame wall reaches it. With a direct injection engine, the fuel is injected at the point it is supposed to ignite and that would remove the possibility I would have though.

Everything's conspiring against me lately (boost gauge and EGT probe failures to name two) so I've made no progress to speak of except to report that I tried propane fumigation and got the same, maybe a little less pronounced knock once sufficient quantities are injected.

BTW, yes, mine is an In-Direct Injection diesel engine with prechambers.

If the knock is not pre-ignition then I'm at a loss to explain it (detonation maybe?) but would maybe give reason as to why my engine is still in good working order, for which I'm grateful.

As regards my fuelling vs boost (without WI), it puffs a small cloud of soot/haze during boost lag but once up to peak boost, there's no noticeabe smoke (viewed in mirrors).

[nutron]

I have tried butane/propane in mine and it worked fine but again, burns hot and fast so you should have the water injection with it. I'd reduce the fueling lower down then if you can and increase the water/methanol injection.

[Supra1]

Originally Posted by nutron

I found on mine that below 50% methanol I lost power aswell. Running 100% water seem clean up smoke though, which I did not expect from my research. Possibly because with the reduced cylinder temps, the unburn fuel doesn't carbonise as it would in the absense of oxygen in a normal heat cycle.

Methanol obviously burns hotter and faster than diesel and there is only a limited amount of oxygen available in the cyclinders as has been said. As you pump in more and more methanol, it will burn in preference to the diesel. This is because it burns faster and because you can burn twice as much methanol in the same amount of oxygen as you can diesel. So as the smoke increases from adding more methanol, it's the diesel that isn't burning on the whole that is producing the smoke, not the methanol.

The burn temp of diesel under atmospheric condictions is about 800 Deg C, where as Methanol burns around 1200 Deg C. As you increase the pressure, these burn temps increase and the thermal energy has to be disapated before the next burn or it will build up. In my experiments, I found that 70% methanol gave virtually the same if not slightly lower EGTs than just adding more diesel until I hit max power. So i would recomend you start at 50:50 and go no higher than 70:30 methanol:water mix. Getting the right mix for your engine will be trial and error using measuring equipment to avoid damage. methanol burns hotter and faster, water retards the auto ignition point because it cools the mix

I would retard the amount of diesel you are adding and add more water/methanol as you can get more torque for the same power this way. The water expanding into steam obviously creates alot more pressure than just heating the air in the cylinders. the amount you are injecting is tiny to be honnest. You are using american gallons per hour (gph) (American gallons too which are about 3.79ltr) nossels which are based on 100psi of relative pressure at the nossel into atmosphere pressure. Without testing the pump pressure and a graph from the supplier such as Aquamist can supply for their nossels, of flow over pressure for a given nossel; you have no way of knowing what amount of water you are actually delivering to the engine.

I currently inject about 1.135 ltrs per minute into my 1.9 common rail turbo diesel. That would be about 68.1 ltr/hour or 18gph to compare to your nossel markings. So I'm not supprised that you are seeing very little chages with your small nossels.

One thing I am interested by is the knock, as the auto ignition point of methanol is significantly higher than that of diesel (diesel = 210 C, methanol = 470 C). So in order for the methanol to be pre-igniting, you would have to have unthinkably high cylinder pressures, that would without a doubt be giving massive rises in EGTs if the engine was actually capable of withstanding them (which I find implausable at best). So I think you need to look to a different reason for this knocking sound, which may well be the methanol but not as you think. The specific heat capacity of water of massive, that's why we use it for cooling, fighting fires, e.c.t. Methanol however isn't as good and as though it would cool the intake charge, on it's own it could expand and create higher cylinder pressures and temps (this is only a theory). If you have a non-dirrect diesel injection with a pre-ignition chamber, the diesel might be igniting at the wrong point, or it might be igniting, and creating a sufficiently high temp to then ignite the methanol in the cylinder before the flame wall reaches it. With a direct injection engine, the fuel is injected at the point it is supposed to ignite and that would remove the possibility I would have though.

Knock occurs in a spark ignition engine when the pressure and temp are so high that you get compression ignition, independent of the spark. you can get pockets of fuel igniting beyond the flame wall, sending multiple flame walls across the cylinder, causing shock waves which you hear as knock. A diesel engine does this normally anyway.

Without knowing more about the sound, vibrations, boost, I don't think anyone can give sound advice on what your problem is. I would try reducing the amount of diesel, replacing it with a 50:50 mix of water:methanol, increasing the amount you inject and see how you go.

This is fantastic information. I have a tow vehicle for my race car (Kia 2L diesel Turbo) and I want to increase Fuel Economy. I have a 0.6mm - ~300cc/min single nozzle, I haven't installed anything yet and Im happy to increase the nozzle size (better before I install).

The goal with the water injection is to spray water into the intake to act as a fuel additive so the car needs less fuel to accelerate at the same rate. I want to start spraying as early as possible (ie 2psi) and keep spraying through the entire range.

Now I look at your post I'm wondering if I have the right sized nozzle.

Any help/comments are welcome!