What kind of kit are you running and what opinions do you have of it?
What was your solution and experience mitigating this?
Water/methanol injection (1 Viewer)
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What was your solution and experience mitigating this?
That's good info @GTSSportCoupe . Did you ever try a mix with lower meth percentage or even straight water? I only used it on my DI engine so never had this problem.
I wonder if dialing down the methanol pump and smaller nozzle will fix the issue.
GTSSportCoupe
2LTE abuser
Various details of my vehicle are here: New Member in Victoria, LJ78 - https://forum.ih8mud.com/threads/new-member-in-victoria-lj78.631504/#post-7972398
This is the kit I'm running: Devil's Own Methanol/Water Injection system. 250psi pump, progressive controller (in cab), and D04 (252ml/min) nozzle post intercooler. Run 50/50 meth/water in winter, and 20/80 meth water in summer. Comes on at 15psi. Nozzle is placed where EGR used to be on the intake manifold.
Yes, going to 20/80 meth/water fixes the problem, but also takes away the power advantage. Maybe the water is still good for cylinder cooling, but I don't notice anything in water temp or EGT.
Quite possibly it would. But then I loose the power advantage, so not sure it's worth it.
Some interesting info on snow performance v2 nozzles vs what’s on the chart.
Methanol pre-ignites in diesel engines. That's what causes the high combustion pressures and damage.
As you turn down the methanol amount it reduces the volume until you can't hear it. But until it's gone you've still got pre-ignition which rapidly advances your diesel ignition speed and increases engine stress a lot.
This goes for any fuel introduced via the intake on a diesel. Doesn't matter if it's petrol(gasoline), lpg/propane gas or alcohols.
Which is why diesel engines don't inject fuel until it's ready to be ignited.
As you turn down the methanol amount it reduces the volume until you can't hear it. But until it's gone you've still got pre-ignition which rapidly advances your diesel ignition speed and increases engine stress a lot.
This goes for any fuel introduced via the intake on a diesel. Doesn't matter if it's petrol(gasoline), lpg/propane gas or alcohols.
Which is why diesel engines don't inject fuel until it's ready to be ignited.
Using water/meth injection as a power adder is actually less stress on your engine. Don't take advice from people commenting about stuff they have never used or tested. More power is made much more safely due to the igniting delay and the higher cylinder pressures from this increase of power is occurring well after TDC. When you increase fuel and boost to make more power it causes the higher cylinder pressures to spike closer to and even before TDC in a lot of cases. Water/meth injection is by far one on the best upgrades you can do to a diesel engine.
Here's some more articles I found in a 30 second google search on just some basic info about water/meth for those looking for easy articles to read without getting into all the in depth SAE research papers;
Water Methanol Injection: More Power, Less EGT
Water Methanol Injection: More Power, Less EGT Some of the most underrated performance parts in the industry are water-methanol injection systems.www.dieselworldmag.com
Water/Methanol Injection: How It Works And What It Does
Water/Methanol Injection is agreat way to boost power. QWhether it's the right way to do that in your truck is up to you.www.dieselarmy.com
Thanks for this video it shows proof that it doesn’t increase fuel injection timing and cylinder pressures.
GTSSportCoupe
2LTE abuser
I actually did all the math on it at one point; based around the 470C auto ignition temp of methanol. Using intake air temps (post intercooler) and compression ratio etc. Yes, it's not great for diesels; and definitely worst for turbo IDI I think (pre-cup holds enough heat to pre-ignite the methanol). I thought it was ok for TDI diesels to a point; but maybe you're right.
In any case, I guess the 2LTE pistons are tough, because I've been running it for 10 years now, and haven't broken a ring land, haha.
One other risk I wonder about with it is cylinder wash effects and increase wear in the bore. If the nozzle isn't atomizing enough or is poorly placed this could be a real risk I think.
Which video is what and how does it claim to prove it?
Video is 11 years old so who knows.
Apparently snow performance v2 nozzles and pump atomizes more then the old nozzles and pump combo. I need to dig and research more about this technology.
I find this very interesting, ive been thinking about adding water meth for a while now, albeit in very low meth percentages, as i believe that at around 20% or less the water would quench the pre ignition of the meth to almost zero, but i have no proof of this, while still taking advantage of reduced egt temps and the torque of steam expansion and lower iat's.....
if you find that sae paper id love to hear your thoughts
if you find that sae paper id love to hear your thoughts
looks like a #4 nozzle will do me just fine
Any alcohol that goes through an engine is burnt. The only question is: How long does it take to ignite?
Does it ignite from the heat of compression or does it ignite with the first ignition of the diesel spray? Both increase the speed of combustion and advance timing. Increasing peak pressures and stress.
This extract below is taken from one of the articles I provided early but nearly every single SAE paper and research document I've read confirm the same thing;
"There are some rumors that adding water methanol will advance the timing of the engine and create a spike in cylinder pressure before Top Dead Center (TDC). This would cause unwanted stress on rods and other components and if large enough, could actually damage components. What is actually happening is that the water/methanol mixture is cooling the air inside of the cylinder, which means that there is less heat energy available to start the combustion process.
The fact is that ignition actually happens slightly after when it normally would or another way of describing it would be that the ignition seems like it’s retarded. The second side of this equation is the methanol. After much research, you’ll find that methanol has a lower cetane number, which means it has a higher auto ignition point than diesel. This means that the diesel ignites before the methanol and thus is what ignites the methanol.
Because the cooler charge temperature is retarding the timing, by the time methanol actually starts to add power, it is after TDC and the increased pressure caused from the expansion of the methanol being burned is met by a retreating piston. The increased pressure is what most would call “safe” pressure. Meaning it is going the same direction as the assembly and not against it, (much less likely to harm anything)."
"There are some rumors that adding water methanol will advance the timing of the engine and create a spike in cylinder pressure before Top Dead Center (TDC). This would cause unwanted stress on rods and other components and if large enough, could actually damage components. What is actually happening is that the water/methanol mixture is cooling the air inside of the cylinder, which means that there is less heat energy available to start the combustion process.
The fact is that ignition actually happens slightly after when it normally would or another way of describing it would be that the ignition seems like it’s retarded. The second side of this equation is the methanol. After much research, you’ll find that methanol has a lower cetane number, which means it has a higher auto ignition point than diesel. This means that the diesel ignites before the methanol and thus is what ignites the methanol.
Because the cooler charge temperature is retarding the timing, by the time methanol actually starts to add power, it is after TDC and the increased pressure caused from the expansion of the methanol being burned is met by a retreating piston. The increased pressure is what most would call “safe” pressure. Meaning it is going the same direction as the assembly and not against it, (much less likely to harm anything)."
JDM Journeys
Moderator
I've been planning on w/m injection for a long time... After boost. Which I've also been planning. Do you think this heat soak effect in the pre-cups would be less on a larger IDI like the 1hz? Or is it more an artifact of high boost levels? A buddy of mine has been injecting w/m into his 2.5L mitsu 4d56 for years to great effect, here in the mountains. After mild boost and i/c I am thinking water meth adds a little more oomph while keeping things squeaky clean. Esp since I don't want to do a front mount (for reasons of room, a/c efficiency and engine water temps).
JDM Journeys
Moderator
Ironic that autocorrect changed pre-cups to precious. Lol. I guess they are?
