I'm really looking for anyone that has ACTUALLY installed or built their own kit. Interested to know what components were used and how injector sizing was determined. Any and all details as available are of interest.
I have a SureFlow water pump that would make a stout supply pump for a relatively low pressure system....
I also have an old Spearco WI kit meant for forced induction gas engines, that will finally make it's way onto my custom built turbo'd VW. I thought about using it on the bus, but my car actually NEEDS it just to survive much beyond 10psi boost (newer cars are so fast that 15-17lbs boost will be needed to get under 13 secs; traction is a major issue with FWD). Using excess fuel to lower combustion temps (which is/was done), isn't exactly the best approach (for longevity).
So the technology has been around for a long, long time, benefits are PROVEN. It just takes some work to make it happen.
Here's a great graphical of the benefits:
http://www.aquamist.co.uk/dc/technic/technic.html (http://www.aquamist.co.uk/dc/technic/technic.html)
I anticipate more than a few naysayers and such, which is fine-- but telling me how the world is flat, won't help, sorry. But, Thanks. ;D
Okay, so let's see what happens with the flood gates opened! But, seriously, thanks for ANY GOOD INPUT OR INFO! :D
Whilst I don't claim any particular expertise on the subject, particularly in relation to diesel engines, I'm curious about the logic for wanting to do this; I've always understood that water injection is used to prevent detonation on highly tuned engines running with very high compression ratios and/or cylinder temperatures. It isn't a tuning method in itself, and (I presume) would offer no advantage at all on an otherwise standard engine (quite the reverse possibly).
Or am I wrong?
Jeremy
Back in the early 1950's, right after WWII, my dad had water injection on his 1940 Chrysler Traveler "straight 8" with a high compression head and many other performance modifications. The water injection did prevent detonation. How it would work on a diesel engine I don't know, but it does work to prevent detonation on a gasoline engine.
Another interesting thing back in those days they used a sandblasting type rig with ground up walnut shells to "de-coke" engines, both aircraft and automotive. Didn't have to disassemble the engine, just turned the engine over so both intake and exhaust valve were open and blast in the walnut shells! Got rid of all the carbon build-up on the valves and the cylinder head! Don't know if this is still done or not.
Adding the correct amount of water will assist in that the water cools the combustion gasses. It also expands as it turns to steam increasing the cylinder pressure.
The trick is to put in just enough water to make up for the reduced volume of the cooler combustion gasses. Too much & you put out the fire (so to speak), not enough & you aren't getting the maximum benefit.
If the engine is tuned for water injection, you probably can't run it with out water as the detonation would kill it.
As for a diesel, the same process applies - too much water in the intake charge & you won't have enough heat from compression to fire the fuel - OR, you could inject the water after the diesel fuel has ignited, but that'd take a high pressure pump . . . .
I'd think the reason it isn't done on production vehicles is because there are more reliable/ less costly ways to make power.
Nitrous oxide works too . . . . but, that is a different process than adding the water . . .
Quote from: kyle4501 on March 31, 2010, 01:56:37 PM
Adding the correct amount of water will assist in that the water cools the combustion gasses. It also expands as it turns to steam increasing the cylinder pressure.
+++ Which in turns would increase HP/TQ (unlikely to be substantial unless turbo'd) and reduce the EGT, which in turn makes both the driver and engine happy.
If the engine is tuned for water injection, you probably can't run it with out water as the detonation would kill it.
++++ That would apply to a NA engine, certainly-- at least under much load. Turbo's have dynamic compression due to variable boost levels, and would not "kill it", all things being equal, but will allow higher boost, for more hp/tq, w/o killing it-- of course it will run, however. In my particular case, gas engine, the engine is "built" for higher boost (currently achieves about 13.5/1 compression at 12lbs boost; 8.9 is static comp.), but requires more intercooling due to a smallish charge cooler that doesn't get very good airflow. Increasing air density, or preventing loss (more common) is always a moving target.
As for a diesel, the same process applies - too much water in the intake charge & you won't have enough heat from compression to fire the fuel - OR, you could inject the water after the diesel fuel has ignited, but that'd take a high pressure pump . . . .
++++ Right-o, I concurr.
I'd think the reason it isn't done on production vehicles is because there are more reliable/ less costly ways to make power.
++++ Me thinks the real reason is the OEM responsibility that comes with an "add on" system. It requires maintenance. How many people actually keep their washer fluid tanks from running out? :o
Nitrous oxide works too . . . . but, that is a different process than adding the water . . .
++++ Could be an interesting show, in a diesel, but will leave the honors up to someone else to try that one. Thanks for the thoughts.
Quote from: Jeremy on March 31, 2010, 01:06:05 PM
I'm curious about the logic for wanting to do this; I've always understood that water injection is used to prevent detonation on highly tuned engines running with very high compression ratios and/or cylinder temperatures. It isn't a tuning method in itself, and (I presume) would offer no advantage at all on an otherwise standard engine (quite the reverse possibly).
Or am I wrong?
Jeremy
Goal/Logic:
1. Slight increase in hp/tq where it's needed, at the bottom.
2. Reduce fuel useage at high loads while accesending a grade.
3. Lower EGT to help protect engine
4. Capitolize on ancient technology
You didn't look at the graphic did you (see link)? ;)
Yes, there is a benefit. However, there is some unknown as to the exact benefit for a diesel where the cyclinder temps are much lower, but the principal applies: both are IC engines, just using different fuels-- BUT diesel has a lot higher BTU content that gas, so.....(those are rehortical periods....for someone who knows, to quip in....)
Certainly: an improperly setup system could damage the engine due to hydrostatic lockout...but that's only, and i do mean only, going to happen when the eninge is stopped (intentionally). I've cranked over enough gas engines with blown headgaskets and the engine just stops, no bent rods-- most on "domestic iron", where the customers didn't change the coolant enough (or ever). Ruling that out (a dripping system), it's unlikly, VERY much so, to ever happen (damage) while the engine is running. Maybe a water hose shoved past the throttle body would do it. Seriously, it would take a lot of water.
The industry has changed a lot over the years. Water/Methanol injection kits are getting fairly high tech. For the person spending $500 on a kit, it's a bit more than a simple on/off operation (like my kit). Again, check out the link, or just search in your fav www "engine".
But thanks for the input, maybe we'll all learn something new-- I sure hope to.
I wasn't thinking about the dangers of hydraulic-ing the engine (presumably you'd have to be injecting a lot of water for that to happen), merely that if the engine is otherwise standard, lowering the combustion temperatures must be taking things away from the optimum conditions within the cylinder which the original designers worked hard to create. If the water injection is for occasional use when the engine is being forced outside it's optimums (ie. going up long, steep hills etc) then that makes perfect sense.
Just to be clear, I'm not saying it's not a good idea - I'm not qualified to do that - just trying to understand the logic of the idea for my own education.
Jeremy
I know that big Diesels-like in ships and power plants, use water mist injection as a means to cool and control NOx output. BUT-there is a fine line between making a difference in performance and injecting too much and water locking the engine-read overhaul time. About the only injection I would goof with is adding Propane injection. Good Luck, TomC
Propane injection is another great method from what I understand to increase power. I've thought about it....not only for the bus, but also for my custom built, and semi-self designed, turbo'd gas engine setup.
Somewhere years ago, Nissan entered a propane twin turbo 300ZX in the Pikes Peak hill climb. Thought it was stated propane offers over 100 octane, maybe it was either 103 or 130. Nevertheless the car was fast and was an eye opener for other technology.
It's possible Propane would be a better solution than water injection, but could possibly be combined together for an optimal setup-- however rather complicated if building it oneself. Something a true busnut might just take on.
The light duty diesel market has come out with propane kits and the benefits are impressive. Propane to aid complete combustion, increase power with H2O injection to keep temperatures down. Combined with biodiesel might make an ancient engine design not too far off the emission output of late model computer controlled versions, possibly with comparable power. I love bussing, but don't love having a piss poor carbon footprint everytime I drive the beast.
Anyway, just thought I'd test the waters here, so see if anyone had some actual experience. Probably I need to get involved with a specific forum that focuses more on the actual component building, and determine the application benefits on my own. This wouldn't be the first time and it's always challenging, but fun and rewarding when postive results are and have been consistently produced.
Thanks all-- over and out.
I have been interested in propane but haven't done it yet. From what I've read, the big benefit is if you have a turbo, but there is supposed to be a small boost without it.
Yep, adding more fuel can't help much if there isn't enough air (oxygen) for it to burn.
That is why nitrous oxide can significantly increase hp.