Diesel using WMI?

[Dust Buster]

Has anyone dialled in water-meth-injection (WMI) in a diesel motor?

I don't get any quench at 100% water, but if I add any alcohol at more than 5%, I start getting bucking (not running smoothly, diesel knock). If I increase the alcohol any more, I start getting blue-white smoke.

[HiPer Express]

At what point you start adding it ? WM is used to cool exhaust temp when it gets too high , nothing else. Straight water is better if freezing is not a problem.

[Dust Buster]

At what point you start adding it ? WM is used to cool exhaust temp when it gets too high , nothing else. Straight water is better if freezing is not a problem.

My settings are:
7 psi for minimum (start) and
50 psi for maximum

Seven is one psi above my normal cruising boost pressure. My scan tool says that 1.53647065 bar (22.285 psi) is my maximum commanded boost pressure.

I was hoping to burn the 20% unburnt diesel by the diesel igniting the alcohol for even better fuel economy.

Freezing is not a problem near home, but snow was just reported in the mountains that I'll be passing through next week.

[BLSTIC]

20% unburnt diesel seems like an incorrect figure for a cruise situation. How did you arrive at that figure?

And also did you actually mean 5%? That also seems like an unusually low amount for symptoms to appear at given that LPG gets used as a substitute/power adder in diesels all the time and you shouldn't be approaching that level of fueling (and alcohol has a higher octane as well) at 5%.

[Dust Buster]

20% unburnt diesel seems like an incorrect figure for a cruise situation. How did you arrive at that figure?

And also did you actually mean 5%? That also seems like an unusually low amount for symptoms to appear at given that LPG gets used as a substitute/power adder in diesels all the time and you shouldn't be approaching that level of fueling (and alcohol has a higher octane as well) at 5%.

The 20% unburnt diesel came from scientific papers when I was researching the addition of LPG, but that could have been their test motors.

Yes, 5% is correct. Perhaps I should add that I have a small diesel motor.

[HiPer Express]

There is no unburnt diesel if the engine is not smoking , and it should not when crusing. I remember Banks did some WM testing and they found out that methanol raises exhaust temperature because it is additional fuel. So if you have unburnt fuel , methanol makes situation even worse.

[Tuner]

Has anyone dialled in water-meth-injection (WMI) in a diesel motor?

I don't get any quench at 100% water, but if I add any alcohol at more than 5%, I start getting bucking (not running smoothly, diesel knock). If I increase the alcohol any more, I start getting blue-white smoke.

The large heat absorption in evaporating the methanol is lowering the temperature at the end of the compression stroke where high temperature is necessary for diesel ignition. Diesel ignition is enhanced by higher temperature intake air and higher temperature at end of compression stroke and time of injection.

[Dust Buster]

The large heat absorption in evaporating the methanol is lowering the temperature at the end of the compression stroke where high temperature is necessary for diesel ignition. Diesel ignition is enhanced by higher temperature intake air and higher temperature at end of compression stroke and time of injection.

I think I understand that heat is being sucked out when the liquid changes into a vapour (enthalpy or latent heat of vaporization of the fuel) as heat energy is required for this transformation. Lower EGT may prolong my turbo's life possibly by preventing coking of the oil lines.

I found it interesting that the mix was better at lowering the temp than either water or alcohol alone.

At my current nozzle size, I'm injecting 1.27 parts of mix for every one part of diesel.

[Tuner]

I found it interesting that the mix was better at lowering the temp than either water or alcohol alone.

This is because the combination of the large heat capacity of water and large heat of vaporization of methanol gives the mixture the benefit of each.

[Dust Buster]

This is because the combination of the large heat capacity of water and large heat of vaporization of methanol gives the mixture the benefit of each.

Got it - thanks

Is my set-up injecting too much? I'm potentially injecting 1.5 gallons per hour in an 89 CID motor. As at my maximum boost I should be at 51.8% (22.285/(50-7)) maximum injection rate, that should be 0.77 (22.285/43 * 1.5) gallons per hour, but I get knock from the start of boost.

[Tuner]

Has anyone dialled in water-meth-injection (WMI) in a diesel motor?

I don't get any quench at 100% water, but if I add any alcohol at more than 5%, I start getting bucking (not running smoothly, diesel knock). If I increase the alcohol any more, I start getting blue-white smoke.

The large heat absorption in evaporating the methanol is lowering the temperature at the end of the compression stroke where high temperature is necessary for diesel ignition. Diesel ignition is enhanced by higher temperature intake air and higher temperature at end of compression stroke and time of injection.

Copying the following paragraph from this link
https://s0.whitepages.com.au/0c6653ac-4 ... cument.pdf
and adding further description in parenthesis ...

The injected liquid fuel droplets must reach distillation temperature and vaporise before ignition occurs. This requires a time delay between the points of injection and ignition. If the commencement of ignition is further delayed for any reason (low temperature at the time of injection resulting from water heat capacity and methanol evaporation) then there is an increase in the volume of uncombusted fuel in the combustion chamber and when ignition does occur (a larger mass of fuel ignites simultaneously), the result is a rough running engine (known as diesel knock).

[Dust Buster]

Copying the following paragraph from this link
https://s0.whitepages.com.au/0c6653ac-4 ... cument.pdf
and adding further description in parenthesis ...

The injected liquid fuel droplets must reach distillation temperature and vaporise before ignition occurs. This requires a time delay between the points of injection and ignition. If the commencement of ignition is further delayed for any reason (low temperature at the time of injection resulting from water heat capacity and methanol evaporation) then there is an increase in the volume of uncombusted fuel in the combustion chamber and when ignition does occur (a larger mass of fuel ignites simultaneously), the result is a rough running engine (known as diesel knock).

So many sources -
https://www.dieseltechmag.com/2010/04/1 ... ou-need-to
The cetane number or speed of combustion (time from start of diesel injection to start of auto-ignition), is important to combustion ignited combustion CIC motors, such as diesel burners. Methanol has a cetane rating of four which means that it increases ignition delay. The lower cetane number of methanol indicates that there is an ignition delay, but the exploded power will occur past TDC (down stroke) in a CIC meaning it is safe power. After ignition, the cylinder pressure rises at a faster rate so "diesel noise" is slightly increased, especially as the exhaust valve opens, but peak cylinder pressure is only slightly higher due to the ignition delay and the combustion conditioning effect, though the available diesel is more efficiently burned in the later diffusion-controlled stage of combustion.

[Leftcoaster]

Is my set-up injecting too much? I'm potentially injecting 1.5 gallons per hour in an 89 CID motor. As at my maximum boost I should be at 51.8% (22.285/(50-7)) maximum injection rate, that should be 0.77 (22.285/43 * 1.5) gallons per hour, but I get knock from the start of boost.

More information please: 89 cid is 1.458 litres - - how many cylinders - - bore/stroke - - 2 or 4 valve per cylinder - - OHC or cam in block - - direct or indirect injection - - originally NA or blown/turbo'd - - how pressurised now - - cam/s changed - - static compression ratio - - mainly coastal or high veldt operation - - daily driver, drag racing, heavy towing, high road speeds or?

[Leftcoaster]

Wikipedia suggests you have a Toyota 1N-T 4cyl 1453cc engine, 74.0 x 84.5mm bore/stroke, 22.0 to 1 compression INDIRECT INJECTION, not direct injection engine
IDI engines create TWO combustion events for each power stroke, the first (partial) combustion occurring within the pre combustion chamber, followed by (hopefully) complete combustion within the combustion chamber proper
This site's "Turbo Diesel Flow Gain" thread discusses power mods to a Toyota 2.4ltr IDI engine, which provides useful information relative to your mods

[Dust Buster]

More information please:

Certainly
- 89 cid is 1.458 litres – yes, 1.461 litres actually, 89 was rounded
The 1.5 GPH is 94.64 ml/min flow rate currently.
- how many cylinders - 4
- bore/stroke - 76 x 80.5mm
- 2 or 4 valve per cylinder - 2
- OHC or cam in block - OHC
- direct or indirect injection - direct
- originally NA or blown/turbo'd – original and still variable geometry turbo
- how pressurised now - 1.53647065 bar commanded, no change
- cam/s changed - original
- static compression ratio - 15.2:1
- mainly coastal or high veldt operation – I live in Cape Town, which is on the coast. (insightful question – I will heading through some high veld (near Lesotho) on my way to Kruger in the low veld next week, but will use 100% water filling in the morning to avoid freezing the reserve.)
- daily driver, drag racing, heavy towing, high road speeds or? - daily driver, mainly interested in fuel economy, but don't mind some kick if available.