DIY Water Injection

[ByTheSea]

I put a very ghetto water injection in my Loyale today and took it for a 200 mile test ride.

Vehicle is a SPFI lifted wagon with 26.3 inch tires with Cut air-box, turbo cams, 2.25 cat back and accel coil with a fresh tune up, 22 degrees advance on 93 octane.

The injection set up was a reservoir and washer pump from a 79 F-150 and the injector was a 1/8-1/4NPT barb with a 1/4 cap(the cap is a tight fit and I'd use a 3/16 if doing again). I drilled the cap with the finest wire bit I had and then peened it down to micro fine size. I couldn't get spray on the first try but I got a very fine stream. The whole thing plugged into the intake tract in place of the valve cover breathers which are in a dump can anyway(reduces intake temps in older motors suffering from ring blow-by like mine). Bottom line real world test was that the set-up flows too much water and doesn't aerate enough. I tried several very high rpm runs. I held 7000 rpms in first for about ten seconds but while the detonation was controlled well the motor got a little ragged and and started dropping firings(wetted plugs I bet). I tried again with bursts of water instead of a steady flow and it worked better till I got a little scared of losing the motor. The next run was on the highway. I ran up to 6000 RPM in third using burst again and had no problems. During these runs the car was loaded to full capacity with me, two kids, German Shepherd, two bench grinders, a drill press and my standard 75# tool box as well as clothes and wheeled toys(we were moving back from summer at the Cape). I'm going to see what I can do to get some aeration and maybe throttle the water down a bit with a valve inline. My other option is to buy a real nozzle from Aquamist. I'm also wondering whether I could get away with piggybacking a SPFI injector onto the MPFI circuit and going with a high capacity booster pump like a Bosch from the VW CIS injection. This would allow me to have an rpm adjusted flow rate set by system pressure. So anyway it's back to the drawing board for now.

[TheSubaruJunkie]

What is the water spraying into? Intake? INtercooler? IS this a turbo car or just SPFI? What is water supposed to do. My understanding is that water is bad. It doesnt compress, and it doesnt burn. Meaning, it cant do much good to an engine other than cooling.

 

-Brian

[Hondasucks]

My understanding is that it cools down the combustion temperature, helping prevent knock. I've also heard that it helps the fuel burn better, but I forgot why, read a big paper on it a while ago, talking about Pogue Carburetors and such.

[ByTheSea]

Brian,

This is a Normally Aspirated SPFI. The spray enters the intake just before the throttle body. The water spray is meant to help lower the cylinder head temps and control detonation. The other ways to do this are to add extra fuel, retard timing or reduce engine loads. Gasoline also does not compress, as it's a liquid. Motors work because the air/fuel mix is mostly air which compresses. If you add water to the equation in reasonable quantities it just vaporizes during ignition. If it's introduced as a fine mist it can actually help get more A/F mix into the cyclinders(denser charge=more go power). I just want to run cheaper gas while retaining enough timing advance to get off the starting line and enough power to go up hill at 80 mph Currently I have to run better gas but I only need it under extremes so most of the time it's wasted. The water would be for those hard moments only like hills and high revs. Water injection on normally aspirated cars is an old accepted concept. American car builders have used it on vehicles meant for the Mexican market as they used to be infamous for having really low octane gas down that way.

[Myxalplyx]

Has anyone else on this board attempted water injection on their vehicles? I'm not talking about in normally aspirated like the previous poster but on turbocharged models? I know Skip had done it but haven't read about anyone else doing it.

 

Skip,

Are you selling any units like the one you made up on the boards for use on the turbocharged models? Thanks!

 

*And yes, I'm digging through some old posts for info* :-p

[carfreak85]

If your car is non turbo, take those turbo cams out because they aren't doing anything but hurting your car. Turbo cams are set up for turbo cars and have too long of a duration for a normally asperated engine.

[Subi81]

I think skip has exparemented (s) with this on his turbo wagon

[Myxalplyx]

I think skip has exparemented (s) with this on his turbo wagon

Yeah, I remember the pics of Skip's engine bay and I remember seeing the water injection. I'm surprised there haven't been more discussion on this being though the turbo models have such a high air intake temperature. I know we have the option of browsing the NASIOC boards for more info but if people here have applied it, I'd love to hear/read their input on this and how to apply it. I may need it sometime in the future and want to be prepared.

 

Some think it's a crutch or band-aid I know. I'm just looking for what works and is affective at keeping detonation down when the boost is cranked up. Timnig retard, better intercoolers, more fuel, I'm familiar with. I'm looking for that point at which your fuel is limited by your injectors/pressure/pump/octane and where the water injection could become of great use.

[NorthWet]

... I couldn't get spray on the first try but I got a very fine stream...

I looked into misters (for two greatly different purposes) a couple of years ago. The physics of misters is a little different than you might think.

 

What you really want is for the water stream to have to turn (like 90deg.), and the DEPTH of the space behind the orifice affects how well it aerosols.

 

To make this less vague, imagine a metal tube being fed water at one end and capped at the other. Somewhere along its length you drill an orifice. Given a tube diameter big enough to drill, all you will get out of the orifice is a stream.

 

Now, if you squish the tubing so that the orifice is on one of the flattened faces and the distance to the wall opposite is thus reduced, then the stream will start to atomize. At least to a certain point, the more the distance to the far wall is reduced the greater the degree of atomization.

 

Also, if I recall, atomization increases as pressure increases.

 

If you would like, I might be able to dig up links to the site with this info. Just might take a while.

 

As far as what water injection is supposed to do, it is all pretty much about charge cooling. It was used extensively in WWII supercharged plane engines, such as the Mustang. In those apps, they used a methanol mix to further cool and fuel.

 

As far as incompressibility, the water is supposed to be atomized and/or phase-changed. And as was pointed out, the amount of liquid compared to compressible gas is (or should be! ) quite small. You would run into drowning the plugs (as sounds like was happening) before you should worry about hydrolock.

 

IMO, Pogue carbs were just voodoo. Made somebody some money, just not anybody who bought into it.

[RXTurbo]

Corky Bell wrote a very good book on turbo's. It had a section on water injection and its place in the world nowadays (as opposed to WWII tech). Makes for very interesting reading.

[Skip]

Brad, good to see from ya -fine work you

are doing.

The CIS pump may not like pumping H20

but is good for 50 psi min.

 

My side

Just a few empirical observations and comments

 

1) Corky Bell's book "Maximum Boost" speaks of H20

injection as a poor man's "bandaid" for correct tuning

of the A/F mixture. True to a point.

 

but

 

I am a poor man and the cost of RRFPR's, experimental

custom FI management systems and the like are out of my

price range. I am a DIY'r

 

My H20 injection system serves it's purpose quite well - thank you.

 

I will say I do not sell or make available any components

reason:

if a person mounts the reservoir above the combustion chamber

(with our engine's config this is a problem)

Siphoning is a real concern and hydro locking can happen if the

nozzle is positioned below the reservoir and no control valve

is employed.

 

My system uses a 8 psi trigger pressure switch

and is full boat when activated.

 

I have built a dash control for my ignition timing,

I can run it on full advance (26 BTDC) at 15 psi with the H20 system.

I also have an indicator to tell me when to add H20.

I simply retard the timing if it comes on.

BTW

I only use mid grade petrol.

 

 

I also employ a CIS cold start injector

connected to LP (inverted propane torch type bottle) that is triggered at the same

pressure. This may help me run these pressures/advance

without detonation??

 

 

The key ingredients of the system have been pointed out

I will add

a very good "atomizer nozzle" is available cheaply from

"Mr. Mister" a personal water cooling spray system.

Micro fine spray nozzles are available from many sources.

Google is you friend.

 

You are advised to use a filter on the H20 pickup

- these nozzles clog quite easily.

 

Turbo owners:

The pump must be high pressure if you plan to mist

downstream of the turbo output - remember

the pressure in the intake may be over 10 psi, the pump pressure must

"compete" against this pressure.

 

"Shureflo"

pumps are very good and have built in pressure controls.

 

I believe one reason for the methanol mix was to prevent

freezing of the mixture - I use isopropyl alcohol (meth) in the fall

but disconnect and drain the system in the dead of winter.

 

I have been using this system for several years.

Good luck and hope this helps

[WJM]

If your car is non turbo, take those turbo cams out because they aren't doing anything but hurting your car. Turbo cams are set up for turbo cars and have too long of a duration for a normally asperated engine.

 

the 85-86 turbo cams are the same as the carb cams. 87 and up had a specific turbo cam.

[oddcomp]

now this is a bit of interesting reading regardin water/liquid injection

 

in fact the guy uses it to totally replace his intercooler ...

 

http://www.gnttype.org/techarea/turbo/nointercooler.html

 

i have a few.. well alot more interesting tidbits like this if anyone's interested

 

btw new code for the megasquirt will controll water injection based on eitehr intake temps or boost psi <like skips setup but with out the ms box>

[bajavwnsoobnut]

what about using those misters that you can get from home depot for the DIY sprinkler systems that are above ground?

[ByTheSea]

what about using those misters that you can get from home depot for the DIY sprinkler systems that are above ground?

I tried those but they pumped out huge amounts of water in a liquid form. A municipal water system runs pretty high water pressure(65 psi in mine) so the things probably are not designed to mist at the low pressure of the Ford washer pump I used. I gave up the whole idea because it would have cost to much for me.

[oddcomp]

btw people are using methanol injectors for water injection..

actually once you have a pump a regular fuel injector will work.. since they are stainless steel assembly's if i remember right

and a simple injector driver circuit can vary the amount injected dependign on boost psi

[rallyruss]

ok water injection may be cool in some situations. but I must point out that you must be aware that your sprayer system can clog, or run out of water. this may be a problem if you have a motor tuned to run extra advance or boost that relys on the sprayer to compensate.

I think investment in an intercooler sprayer would be more benefical to us turbo guys.

ok I just wanted to point out WHY its considered a "band aid". so as long as you know go ahead have fun. hey it will steam clean the carbon off you pistons. thats a good thing.

oh and like skip said if it leaks it may hydalock a motor whan mounted above the intake.

[NorthWet]

ok water injection may be cool in some situations. but I must point out that you must be aware that your sprayer system can clog, or run out of water. this may be a problem if you have a motor tuned to run extra advance or boost that relys on the sprayer to compensate.

I think investment in an intercooler sprayer would be more benefical to us turbo guys.

ok I just wanted to point out WHY its considered a "band aid". so as long as you know go ahead have fun. hey it will steam clean the carbon off you pistons. thats a good thing...

Water injection is a band-aid (tm ) in another way: It doesn't really change the total "heat" energy in the intake charge, it just stores and/or converts the form of it. If it stays in liquid form, its ability to absorb energy is limited (1 cal/G/degC), so it would take an awful lot to lower the intake charge temp significantly. If you get it to phase-change to steam, than it can absorb much more (11Kcal(?)/g... can't remember if this value is for fusion or vaporization, but both are in same ball park) Significantly lowering charge temp... BUT at the expense of volumetric efficency. The charge temp is lowered, but you get less charge in.

 

Either way, you don't get the amount of intake charge that you would with an intercooler.

 

Now if you ran an intercooler AND had a water injection system that sprayed in such a way that the majority of water was still atomized but not vaporized at the time of ignition...

 

But as Russ pointed out, still subject to clogs, empty tanks, and mischief if it is relied upon to prevent abnormal combustion.

 

... oh and like skip said if it leaks it may hydalock a motor whan mounted above the intake.

There are devices known as vacuum-breaks (anti-backflow) that can be had for larger pipes (domestic water supply). If one could be found/made for the size line that we are talking about here, it would minimize/eliminate the possibility of hydrolock.

[archemitis]

um... it should take power away from a na engine, why would you ever run it on a motor with just 9.5:1 compression, and no turbo?

 

if your na spfi is pinging, you have other problems, that you could fix witout spraying it with water =/

[Myxalplyx]

um... it should take power away from a na engine, why would you ever run it on a motor with just 9.5:1 compression, and no turbo?

 

if your na spfi is pinging, you have other problems, that you could fix witout spraying it with water =/

Well, on another note, if you are cheap and you picked up a system for cheap, it could save you money in the long run. How! Well, if you are pinging on low grade octane in N/A form, of course your car has a problem. If that problem is carbon deposits on your piston tops, then (from what I've read here and elsewhere) WI would help remove carbon deposits and keep the engine clean. If you ran this for a couple of months or so (using low octane fuel since you can now with WI), you may be able to clean those deposits off, freeing you up to be able to use low octane again instead of going 1 or 2 grades higher in octane because of detonation.

 

That's just a stretch though. I agree with you. Just being objective!

[archemitis]

i have steam cleaned several motors, and my cousin has water cleaned, a 300z turbo, and it actualy showed around 15 hp increase on the dyno.

just stick a vac hose, in a bottle of water, and rev herup. =]

 

if you used water injection on na, you wouldnt even need a water pump, just stick the hose in the water, and it sucks it in.

[naru]

if you used water injection on na, you wouldnt even need a water pump, just stick the hose in the water, and it sucks it in.

 

No,That wouldn`t work.In this case more water would be used

under high vacuum than low.Exactly opposite of what is required.

 

"What is the water spraying into? Intake? INtercooler? IS this a turbo car or just SPFI? What is water supposed to do. My understanding is that water is bad. It doesnt compress, and it doesnt burn. Meaning, it cant do much good to an engine other than cooling."

 

It cools the intake charge allowing more optimum ignition

timing w/o detonation or lowers the octane required.

Water vapour compresses OK.

Neither air nor water burn, but both take part in the oxidation of gasoline.Suggest you read this.

http://not2fast.wryday.com/thermo/water_injection/water_chemistry.txt

 

Almost all Formula 1 teams used water injection in the turbo

days(early 80`s) until it was banned.

I don`t think they banned it because it didn`t work.

Here are a few details of its use by Renault.

http://www.aquamist.co.uk/dc/coollinks3/index/race/renaultf1/renault.html

[archemitis]

show me a dyno sheet, it sounds like snake oil unless you have a turbo.

[carfreak85]

Water in small amounts is ok, as long as there is less water than cylinder volume at TDC. Your engine wont run with that much water, but you wouldn't break anything either.