Steam injection pre turbo
 

Why would steam not show the same characteristics as a very fine mist of water when injected pre turbo? My home steamer's mist is not hot further than a few inches from the nozzles- ie it's cool after three inches. I would think with a inverter and a 115 amp alt I could power the steamer and utilize it pre turbo. Thoughts?
I posted the same ? over at WI forum.

You would not gain anywhere near as much power as it takes to make the steam.

The power in water injection comes from the water to steam expansion rate = 1:1,600. Also, the transition from liquid to gas takes (a little) energy. I would think that a vapor mist would work better than steam for this reason. It could not contain any minerals though which could be abrasive.

Incorrect, pure water injection produces no (zero) hp increase. Alcohol (Methanol) must be mixed with the water before there will be any power gain.

Incorrect again, evaporating water takes lots of energy. Thats why it cools the air.

Although I've never had water injection on a diesel, we used it successfully on gas engines w/o methanol and got substantial power gains. I'm pretty sure that it will do the same on a diesel.

water will make the charge air colder, therefore denser. On a gasser, it will allow you to dump a ton of fuel in and it will also allow you to run higher compression ratio without pre-ignition. Diesels do not have this problem, so it really does nothing more than cool the charge air. If you were to dump a ton of fuel into the mix (which we can't do with the stock IP), it might help to keep temps down. Otherwise, as Forced said, there seems like little benefit... However, water injection combined with propane injection might prove useful...

GB is right. Denser air on a gas engine means more air and fuel flow into the cylinders.

Denser air on these mechanical diesels does nothing but help it run cooler. I have used water injection and the difference between no injection and pure water is 0.3HP and 0lb/ft of torque, easily within the error range of the dyno. View it HERE.

Using a 50/50 (by weight) methanol mix at 300cc/min added 3.2hp and boosted torque in the upper RPM range.

It would help the cylinders run cooler- and I think perhaps I'd get a bit less smoke out the tail pipe, which are two good things in my view. The 110 volt steamer (600watts) would take little power from the engine, as it would tax the battery and alt a bit, but certainly not much. WI helps keep the cylinders free of carbon build up also IIRC. There's three things. My real question is the effectiveness of steam. Yes, the cooling of the intake air comes from the water to gas transformation; and thus the conventional wisdom says you cannot get that energy back to cool the air. However, the steam is really no longer steam less than 6 inches from the nozzle, so I fail to see how this applies. Try it- home steamers are just water soakers 4-6 inches from the point of exit. Pre turbo amounts of WI are much less than the post turbo amounts needed for the same effects also. I view it as an overall safety feature if you are running more than stock amounts of fuel, air, and other combustion gases- propane, methanol or alcohol.

Water injection = good if the cylinder temps are getting out of control.

Last week we dynoed 924 HP with Diesel and 949 with a water injection system using pure water. This was a Cummins, not a MBZ though. Not a huge increase, but the system is to save the engine, not add power.

The little MBZ with moderate fueliong increases may see a few ponnies if your lucky, but it may be so small you would hardly notice.:confused:

Once you get one cranked up to 500 or so....then the water may add a few more.

We were only getting about 4HP from water, but tweaked it a bit for 25 more!

:)

Great.... What is needed here is to address the question at hand. If you have information of what you are doing now and how it relates to what I've or others have asked, let's hear it.

My question is if you are willing to go that far, why not get a good pump (~$50) a nozzle ($10) and do it right?

A person could use the heat from the exhaust pipe after the turbo to create steam and it would draw no power from the engine.

You are missing the point. The water is used to cool the intake air. If it is already hot steam there will be no benefit since the water can't absorb heat from the air or evaporate.

I have not found a $60 system that "does it right" for pre turbo injection. Post turbo is complex- you have to have the proper installation at a suitable post turbo/post IC site. I don't have such a site unless it's gonna be right at the cylinder entrance- which means I'll have five nozzles. Your previous system may have had this issue. It also means I have to inject much more water- over 500 cc according to many, including your estimates. Reading thru many threads over at WI show the complexities that accompany post turbo, and even pre turbo.
The major issue with pre turbo is the water drop size- causing impeller damage. Steam condenses if it has the distance/time and will still be small enough water droplets that it should not cause this damage. That's the theory, and until it's hashed out, the subject will not be closed or fully explored.

Does steam stay in gaseous form without further heating? When it enters the cooler realm of ambient air it starts the transformation to liquid. Water in liquid or gas form will clean build up in it's path, and that is a benefit itself. Obviously using heat already made by the engine sounds like a win/win, however I believe both you and I think at this point it may not be worth the time to design, fabricate and install a system based on this.

Pump: $40
Nozzle: $15
Pressure switch: $12
Hose: $10
Tank: Free, share the washer bottle
Total: $77

Suitable means anywhere post turbo and post intercooler. The EGR port, compressor housing, etc.

Don't make it sound complicated. It is very simple.

Pumping 212*f steam into 200*f compressed air isn't going to cool anything.

Wrong, I'm have been working on a port injection system for several weeks. The only thing holding me back is lack of available money.

If you search for "pre-turbo water injection" in google there are plenty of cases where pre-turbo water injection, if done right, does not harm the propeller blades as commonly thought.

The cases where it did where cases where other objects got into the intake.

Is there a way to mist the water without using heat that would work? I know there are cool vaporizers for use in your house. Is there some way to rig up something like that rather than producing steam?

Small nozzle, 100-150psi pressure should do the trick. You don't have to heat the water.

It DOES wear damage the wheel by dulling the blade edges. Don't be LAZY, post-turbo injection is the only right way to do it.

Why are you so sure? There are plenty of accounts where people used it without any harm. Even Saab used it.

That doesn't mean it didn't do any damage. Any wear on the blade edges will reduce its efficiency and loose it's balance.

There are "plenty of accounts" of people using Lovecraft's system too, that doesn't mean they re right or doing what they should be doing.

Saab is an embarrassment to the automotive industry. Their ONLY good point is they aren't afraid to use turbochargers on production cars.

I know this is a lot more complicated, but didn't older diesel engines use water injection ATDC directly to the cylinder? It seems to me, that this would be the best scenario, because you can really utilized the expansion of the phase change. I think that would be pretty sweet to have DI water.

Care to quantify that statement? My brother has an 87 SPG that is a wonderful car to drive, fast, hugs the road, and economy>30mpg to boot... all on 87 octane. Very reasonably priced (far less than my 300TD).. Quite reliable, hardly any maintenance required compared to the benz... My mom drives a GM900S which has proven a very inexpensive car to drive for the last 50k... just oil changes and tires so far.. Once big things start to go bad on them its time to get rid of them, because exhaustive repairs can be pricey, but certainly less of an embarrassment to the automotive industry than, say, GM.. at least in my experience...

As for the pre-turbo WI, seems like a bad idea regardless of the phase the water is in. Seems nearly as bad an idea as running the CCV into the impeller. When I took my turbo apart to rebuild it I got about 1/16-1/8" of encrusted oil sludge out of the housing, which can't be good for airflow...

I wasn't aware older diesels had DI water injection.. That is an awesome idea though, and could be done fairly low-tech. Bruce Crower made a 6-cycle engine recently out of a one-lung diesel that he put a carb on to run on gasoline, and injected water with the injector+IP... I like the idea of injecting H20 ATDC, probably does wonders for emissions too... I wonder if we could get away with installing H2O injectors in the GP holes? Would an IDI diesel have a snowball's hope in hell of starting w/o GPs? Maybe a WD-40 injection system for starting? I bet an EFI common-rail setup like megasquirt or something similar could be constructed fairy simply for the water...

What about those ultrasonic humidifiers that were all the rage back in the mid 1980s? The make such small droplets that they will stay suspended in the air just from brownian motion of the air molecules themselves. You'd need a whole array of the things to atomize water at the rate needed, but it'd be about as abrasive on the turbo vanes as driving through fog. Best part, they don't use tons of power since phase change of the water isn't involved, so you still get the phase change cooling benefit.

I haven't seen them sold as humidifiers in years, but I think the craft stores still sell the equivalant things as fog/mist generators for decorative fountains.

Or you could always generate a heap 'O tiny droplets by bubbling millions of tiny O2 and H2 gas bubbles through some water... Oops.. wrong thread :D.

100 psi would be minimum. The nozzle either has to be spraying a cone right onto the nut which is very very difficult to do properly, or it has to be back some distance and spraying the proper direction to not condensate on the intake walls or form larger drops. Some engines have far greater psi pumps that spray under 5um size drops. The amount pre turbo to simulate post turbo effects is much less- I think close to a 1/4. FI is correct- larger drops will degrade your blades. A system pre turbo must have very very small drops sizes- and that is why I am asking about cold steam. The steam is cold to my hand at 6 inches- so it must have lost quite a bit of it's heat. The real question is this- how long does steam hold it's heat, and does steam when it leaves a steamer nozzle condensate to itself with water surface tension and form large drops?

how about LOX

lox? lol...

You'd throw a rod.. or seriously gum up the engine :D

Some person in a gasser tried that here a few years back by driving through the liquid O2 vapor cloud leaking from a damaged tanker truck. The car was parked about 50 feet past the cloud down the on ramp, and I'd bet they got most of that distance coasting after they threw a rod or whatever :)

If you are going to have a 100psi pump and atomizing nozzle, don't even bother trying to put it pre-turbo.

May I as why do you think so?

Fi, you're a little bit vague for me sometimes.

Read this it's all about pre turbo injection. a 25 page thread.

Lets throw a curve in here, what about water injection in the exhaust stream pre-turbo to provide extra pressure/boost at low power or to spool the turbo faster?

The turbine blades are much more durable than the compressor blades also.

steam wont work because its the water droplets turning into gas (steam) in the heated air that absorbs energy (it takes energy to change states of matter), thus cooling the intake charge.

Because you are already doing all the work (switch, 100psi pump, nozzle, etc). The only thing you have to do is mount it in the intake or compressor housing.

Iron and steel also rust much better than aluminum.

This is really the crux of the matter that everyone seems to miss....

Is steam still steam in colder air? For how long? Steam is obviously hot.... but when you take a home cleaning style hand held steamer
and have steam come out the nozzle- in about four inches IT IS NOT HOT. Since steam is hot, I'm assuming it's no longer steam. Therefore using a hand held steamer to generate steam which is then no longer steam is really just a device to make very very small water droplets.

Something that otherwise takes a very high psi pump and specific nozzles. Normal post IC systems will not do this, and FI is correct in saying it will cause issues with the turbo. I am not talking about a normal post IC system and putting it in front of the turbo. If you want to talk about that make another thread. I'm not talking about normal post IC WI, make another thread. If you want to talk about post exhaust WI, make another thread. Let's get to the bottom of what I am talking about and then move forward from there.

Steam is hot water vapor. Clouds are similar to steam. It will condense if allowed to, but the water vapor is what you have.

The conversion from water liquid to water vapor/gas takes energy, and expands roughly 1,600times. Water vapor also adds to the thermal mass of the intake air and can transfer more heat energy in or out.

True, but at ~900F and with high-velocity hydrocarbons/acids/carbon solids hitting the wheel, I don't think rust is a problem. Plus, put aluminum alloys next to cast iron in a salt-spray environment, and you'll see the aluminum alloy become the sacrificial anode.

I'm just curious about the possible performance benefits, I have spare turbos to play with.

Give it a try.

Sorry if this is to far after the fact, POWER IS POWER,(P=VI) 600 Watt steamer will require 50 AMPS at 12V to run, so you are overtaxing your alternator for this, if you intend to run it for longer than a pass down the track.

I don't think a 115 amp alternator is taxed too much by 50 amps... is it? ;)

Depends on the RPM.

use heat from the exhaust manifold to generate steam

what about a heat exchanger loop wrapped around the exhaust manifold, the downpipe, or wherever, and a regular old WI system (shurflo pump, nozzle, solenoid, etc) that injects HOT water pre-turbo? The "superheated", high pressure water (T>100C) will flash to vapor as soon as it leaves the nozzle due to the pressure drop. You the run the watery mix through the turbo, through the intercooler (yes some will condense, deal with it appropriately), and into the engine...

EDIT: My vote is still for a "IDI" water injection system where the glowplugs are replaced with injectors (like those found on your average FI gasser) and supplied with high-pressure water. A crank position sensor (like the RPM sensor?) provides timing info for a little computer which times your water injection event at some point ATDC (ideally when the diesel fuel injection event has terminated).. Think it will work? It doesn't sound too expensive if using parts from a junk gasser motor...