story by tom suddard and dan hurwitz • photos by dan hurwitz
Water is bad news for almost every internal engine part. It doesn’t really compress, lubricate or ignite–three strikes against it. Plus, if an engine ever receives more than a gentle cleaning with H2O, chances are it will soon need to be replaced–that’s why many Jeeps have snorkels and …
My diesel has water/meth injection and makes a noticeable difference. It was installed before I got it though, so I don't know much about it. But I now have a water/meth kit that will be installed on the challenge car, so fun things to come!
I ran a Edlebrock Water/Meth Injection back in the 80's on a carb Motor. It made great torque then too.
While it works, my feeling is that it's just more stuff to fail (or run out of). Proper systems cost $$$, and then there's where to put everything. It's not just running out of coolant, it's having the pump fail, or perhaps worse, having the nozzles partially plug up. Unless the system's really smart (that's the $$$), it could well be squirting little to nothing yet looking like everything's fine. I ended up taking everything out and installing a big-ass air-to-air intercooler and ducting. I realize this thread is linked to the magazine article, but for me, it was too large a risk.
A buddy of mine has an unrestored survivor '53 Allard K3. It has a Cad engine with three carbs. Each one has a tube sticking into the air cleaner lid, which goes to a glass bottle on the fender. Air moving past the end of the hoses causes a vacuum on the lines, which causes water to mix with the air charge. I knew another guy that had the same system on his '83 Ranger 4-cyl. Same brand and everything. He had it so he could push the timing on the 2.3 to try to get some power out of it. The system works well in both applications.
So...How stupid would it be for me to do this to my 2000 blazer with 201k on the clock?
The ultimate answer here is to have two tunes to switch to. One for meth, and one for Jesus.
Saw a homebrew looking setup on an older Volvo in a junk yard quite a few years back, thought that was rather clever of them, given the apparent age of things.
Have a kit that will be going on my Supra, once I get a TIG and the confidence to weld aluminum with some degree of skill. Car makes plenty of power as it is, so it's more for just keeping the intake temps down than for the ability to crank up boost pressure and timing.
Water injection is pretty great, but it is somewhat less great than injecting other things like Methanol while requiring the same basic amount of hardware to achieve, so a lot of people who would consider water injection decide to inject something else instead.
I agree with the statement about more things to fail. On the extreme upside of water or methanol injection would be my friend's old Plymouth Sundance that he turboed and got about 4x the CHP out of (~500whp) with STOCK IGNITION TIMING using methanol injection. Methanol is a fuel, and he was injecting about 200hp worth of it. So what happens when you need 500hp of fuel and something happens and you suddenly are missing 200hp worth? That's the downside: Building a setup that takes full advantage of having something usually means it is going to blow up when it doesnt have it. Same thing can be said for 'e85 tunes'.
It is not that hard to build in safeguards for things like water/meth failure, but people rarely do it. E85 'blend sensors' are at least becoming semi-common. I personally think that if you are implementing a safeguard to go along with 'it', then it's great. A little electrical knowledge will allow you to piece something together pretty cheaply. For example, i bought a ~$70 2-in-1 gauge from Auber Instruments that has programmable alarm outputs. If i choose to use it to monitor manifold pressure and wideband AFR, i can easily rig up a series circuit that goes through both alarm output 'switches' so that IF boost is above 'x' AND afr is above 'x' (=lean), i can do something like trigger an NC relay in my ignition coil primary circuit and instantaneously shut it down, but the car can still run lean under no-boost conditions. Something along the same lines with a pressure switch in the water injection line is equally doable, and possibly even easier if you already have a fancy engine management setup that can do all of this in software instead of rigging up additional sensors and switches and outputs to do it.
In reply to Vigo :
The article was really for water/meth injection, but I suppose straight methanol would still be different.
Everyone making the points about safeguards for if/when the system runs out or doesn't work when the car is tuned for it is something that hadn't crossed my mind, so I will make sure to build that into my build.
That said, on my diesel truck, the system pumps the washer fluid from a second pump in the stock washer fluid tank, which means when it gets low a light comes on. ;)
Oh it's awesome stuff, but I have to underscore the importance of being able to quickly detect when it's not being injected. Everyone's correctly noting the importance of detecting when the tank's low, but the real danger is when the injector nozzles partially or completely plug up. In that situation, the tank level switch, and driver think all is good and keep powering away, all while intake air temperature is going through the roof. Hopefully the ECU notices the high IAT or knock. Some systems (like AEM) use a flow sensor, which is really the only way to know for sure what's going on, but it's part of a $$$ kit.
BTW, another reason I got rid of it was due to smelling the methanol in the 50/50 water/meth mix while it was injecting. Read up on methanol - it's nasty evil stuff in any form. Alan Staniforth, author and builder of many British cars, died of lung cancer, thought to have been caused by his methanol exposure in both liquid and fume form... For me, I chose to avoid the whole system, so to answer this thread's question - "No."
I know methanol is nasty and was going to ask if anyone had tried doing the same with ethanol, but before I did I thought I'd google "ethanol injection" to keep from feeling stupid. The only hit I got was for PEI, which is Percutaneous Ethanol Injection as a cancer treatment.
I tried again and searched for "ethanol injection car" and got this;
https://www.caranddriver.com/features/ethanol-injection-systems-explained-tech-dept
-I remember my dad rigged up an alcohol injection vacuum operated system. I believe he used anti-freeze which was what was in use at the time. He used a glass bottle which was not secured well and it broke dumping the alcohol onto the spark plug resulting on some flames.
kb58 said:Oh it's awesome stuff, but I have to underscore the importance of being able to quickly detect when it's not being injected. Everyone's correctly noting the importance of detecting when the tank's low, but the real danger is when the injector nozzles partially or completely plug up. In that situation, the tank level switch, and driver think all is good and keep powering away, all while intake air temperature is going through the roof. Hopefully the ECU notices the high IAT or knock. Some systems (like AEM) use a flow sensor, which is really the only way to know for sure what's going on, but it's part of a $$$ kit.
BTW, another reason I got rid of it was due to smelling the methanol in the 50/50 water/meth mix while it was injecting. Read up on methanol - it's nasty evil stuff in any form. Alan Staniforth, author and builder of many British cars, died of lung cancer, thought to have been caused by his methanol exposure in both liquid and fume form... For me, I chose to avoid the whole system, so to answer this thread's question - "No."
So from a safety side of things, maybe alcohol injection is a physically safer route? I would suspect it isn't as good on the intake cooling side of things, but I don't really know anything about it.
Latent Heat of Vaporization is basically the measure of how much cooling effect you're going to get and you can look it up for various things you could inject. Some of them are easier/safer to get, store, not clog up nozzles with, not corrode the inside of the pump with, etc etc.
kb58 said:BTW, another reason I got rid of it was due to smelling the methanol in the 50/50 water/meth mix while it was injecting. Read up on methanol - it's nasty evil stuff in any form. Alan Staniforth, author and builder of many British cars, died of lung cancer, thought to have been caused by his methanol exposure in both liquid and fume form... For me, I chose to avoid the whole system, so to answer this thread's question - "No."
This brings up an interesting safety point about washer fluid too. The fresh air intakes on cars really shouldn't be right by the windshield where the methanol-laced washer fluid ends up...
I haven't read the article but last time I was looking at these systems I didn't like the controls so I built my own. I built an adjustable injector controller based on a 555 timer circuit, machined a block with a boost referenced regulator, a high pressure diaphragm pump, and used a SS injector. The injector cycle was based on both RPM and boost and worked very well.
We used to use Snow stuff - they're not a new company. To implement it properly, you put a flow sensor on the water/meth line. That means you can detect a low tank, a failed pump or a clogged nozzle. When the flow sensor indicates a problem, the ECU should react by pulling timing, adding fuel or dropping boost.
If this sounds like the correct way to implement E85 (with an ethanol sensor in place of the flow sensor), you're right. It's the same concept.
In both cases, you need to measure what's happening and the ECU has to be able to use that information. Where you get into trouble is when you make assumptions: assume that the water is flowing (or that your E85 is 85% ethanol), assume that a stock ECU will be able to adjust, assume that a driver will see a warning light and react.
We actually ran a water injection system in our Open Track Challenge car back in 2002. For those who weren't reading GRM at the time, call it a week-long Time Attack event. Like One Lap, but with less driving between tracks and a full track day at each one. That one was pretty crude, no feedback from the flow and the ECU couldn't react. It worked, but required race car levels of maintenance and inspection to avoid problems. That car also had an intercooler sprayer - coming off at the track at Willow Springs on a 100F day, the IC was cold to the touch.
I think many people are a little too worked up over methanol or any type of alcohol with water injection. The NACA tests of water injection in WWII showed that doubling the rate of injection more than doubled the improvement. The tests also showed that 50/50 methanol was the best but 100% water was still very good.
In other words, you could inject 4 GPH of 50/50 or you could inject 5 or 6 GPH of 100% water to get similar improvements. I just pulled those flow rates out thin air but the idea is that you should just keep increasing the rate of 100% water until you start to lose ignition spark then back off and start mixing methanol.
Water injection should not kill spark until you are somewhere between 100% to 150% of the fuel rate (according to NACA tests). That's a lot of water before you even start to need methanol.
Remember NACA was trying to maximize power versus take-off weight of airplanes while we are trying to maximize power versus money spent. I don't mind a few extra pounds of water if it saves me having to manage methanol inventory.
Back when I was tinkering with the RX-7 some 15 years ago, I added a water injection system solely for the purpose of lowering intake temperatures with elevated levels of boost. I think I had it kick on somewhere between 5 and 10 psi.
As others are getting close to noticing, it's barely one step away from just running the engine entirely on E85. When that occurred to me I removed the injection system and set the car up for flexfuel.
edmagoo said:I think many people are a little too worked up over methanol or any type of alcohol with water injection. The NACA tests of water injection in WWII showed that doubling the rate of injection more than doubled the improvement. The tests also showed that 50/50 methanol was the best but 100% water was still very good.
It's still used by the military, and referred to as AWI, alcohol water injection
This thread is 9 months old.
In reply to edmagoo :
edit: http://naca.central.cranfield.ac.uk/reports/1945/naca-wr-e-264.pdf
guessing it was this, im so used to certain wwii aircraft data being hard to find didn't think it would be so easy. going to try to find others though as certain reports don't always cover all the bases and its usually a fun read eitherway
AW injection was activated when the thottle went to "War Emergency".
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