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Tech Information => Water/Methanol Injection => Topic started by: jl222 on February 14, 2009, 11:57:58 PM

Title: Recardo graph on H20 injection
Post by: jl222 on February 14, 2009, 11:57:58 PM
This graph shows how increase boost and fuel to the limit of power and added water injection to increase the Brake Mean Effective Power from 168 to 240 and also leaning the engine out to where he started.

(http://i162.photobucket.com/albums/t246/bvillercr/IMG_2237.jpg)

Title: Re: Recardo graph on H20 injection
Post by: Dean Los Angeles on February 15, 2009, 01:36:56 PM
The fuel was 87 octane.

The octane rating is a measure of the resistance of gasoline to detonation (engine knocking) in spark-ignition internal combustion engines.

If the same test had been done with 119 octane racing fuel there may have been no difference with water injection. I really doubt if water injection can be of any help on a full pop racing engine.

Water injection is used to lower the temperature of the mixture to avoid detonation. If detonation is limiting horsepower, there are other ways to prevent it. At the limits of racing engines I doubt if water would allow more horsepower to be achieved.
Title: Re: Recardo graph on H20 injection
Post by: McRat on February 15, 2009, 01:47:59 PM
The fuel was 87 octane.

The octane rating is a measure of the resistance of gasoline to detonation (engine knocking) in spark-ignition internal combustion engines.

If the same test had been done with 119 octane racing fuel there may have been no difference with water injection. I really doubt if water injection can be of any help on a full pop racing engine.

Water injection is used to lower the temperature of the mixture to avoid detonation. If detonation is limiting horsepower, there are other ways to prevent it. At the limits of racing engines I doubt if water would allow more horsepower to be achieved.

My experience with water on a dyno is limited to diesels, but I haven't seen a gain at either the dyno or the dragstrip by turning on the faucet, unless you add methanol to the mix, which is just adding more fuel for us.

This flies in the face of the advertising brochures, but so far I haven't figured out how to make more power with brochures, since they clog up the fuel filter.  Stickers?  SURE!  :-D
Title: Re: Recardo graph on H20 injection
Post by: 1212FBGS on February 15, 2009, 02:01:37 PM
i think it has some use.... kinda like a band aid.... So many people use band aids to solve a problem and in so create another problem.... in low boost applications (under 20lbs) it might be a cheep fix.... but IMO if your not using 30lbs boost its not a race engine! I don't think water injection makes more power... it might help with detonation or lower charge temp that will allow increases in performances but you should really be looking at the root of your problems instead of a quick fix... Just something else to brake!
Kent
Title: Re: Recardo graph on H20 injection
Post by: McRat on February 15, 2009, 02:36:04 PM
i think it has some use.... kinda like a band aid.... So many people use band aids to solve a problem and in so create another problem.... in low boost applications (under 20lbs) it might be a cheep fix.... but IMO if your not using 30lbs boost its not a race engine! I don't think water injection makes more power... it might help with detonation or lower charge temp that will allow increases in performances but you should really be looking at the root of your problems instead of a quick fix... Just something else to brake!
Kent

What it is really handy for on a high boost racing engine is to suppress high EGT's which can damage turbines.  That's why I run it.  But if you aren't over 1300 deg with an inconel turbine, you are OK without worrying about water.
Title: Re: Recardo graph on H20 injection
Post by: 1212FBGS on February 15, 2009, 05:57:15 PM
so, are you spraying it into the exhaust?
Title: Re: Recardo graph on H20 injection
Post by: McRat on February 15, 2009, 06:05:48 PM
so, are you spraying it into the exhaust?

No, I spray it in the intake.  Drive pressure, high temps, and the risk of cracking plumbing scares me away from going directly into the exhaust.  But someday I'd like to experiment.  Spraying into the intake drops me about 150 F at the turbine with no apparent risk.
Title: Re: Recardo graph on H20 injection
Post by: jl222 on February 15, 2009, 07:25:51 PM
 
 During WW2 the airplanes had up to 115 octane and they still used water injection and as far as I know the unlimited airplane racers still use it ''ADI'' anti detonation injection. Notice how much Ricardo leaned the engine.
 
In ''The 1000 BHP GRAND PRIX CARS '' this is the first paragraph ''Rocket fuel' made it possible.The ball started  rolling in mid 83 when BMW countered Renault's use of water injection by fuel technology.Injecting water into a turbocharger engine's 'charge air' did more than merely assist cooling; for reasons that had no formal, text book explanation the acted as a combustion stimulant, increasing power. Pre war turbocharged aircraft engines had used water injection injection to extend payload. Having picked up on the idea, Renault and Ferrari denied that water cinstituted a power boosting additive: there was no technical explanation to prove otherwise. BMW on the other hand saw more could be gained through manipulation of the composition of the fuel itself.''

             JL222
Title: Re: Recardo graph on H20 injection
Post by: Blue on March 04, 2009, 12:23:42 AM
This graph shows how increase boost and fuel to the limit of power and added water injection to increase the Brake Mean Effective Power from 168 to 240 and also leaning the engine out to where he started.

(http://i162.photobucket.com/albums/t246/bvillercr/IMG_2237.jpg)

What book is this from?
Title: Re: Recardo graph on H20 injection
Post by: interested bystander on March 04, 2009, 12:33:43 AM
Probably "The High Speed Internal Combustion Engine".
Title: Re: Recardo graph on H20 injection
Post by: jl222 on March 04, 2009, 12:58:14 AM
Probably "The High Speed Internal Combustion Engine".

     This graph came from the book ''Turbochargers'' by Hugh Macinnes [HPBOOKS] quoting information from Ricardo's book. Great info in this book from learning how to figure boost temps, tubo sizeing ,tubo map reading ,tubo staging,intercooling and water injection.

                JL222
Title: Re: Recardo graph on H20 injection
Post by: NathanStewart on March 11, 2009, 06:33:37 PM
Quote
I really doubt if water injection can be of any help on a full pop racing engine.
 

On a naturally aspirated motor you're probably right but forced induction applications almost always see a power increase.

Quote
Water injection is used to lower the temperature of the mixture to avoid detonation.

Actually, water is resistant to combustion (obviously) and you could even say that water has an infinite octane rating.  Add in something that doesn't burn but does absorb a lot of heat energy and you effectively reduce the combustion rate of your air/fuel mixture.  It's a "heat sink" if you will that helps to control combustion and not just cool the mixture directly.

Title: Re: Recardo graph on H20 injection
Post by: Dynoroom on March 11, 2009, 07:02:56 PM
Quote
I really doubt if water injection can be of any help on a full pop racing engine.
 

but forced induction applications almost always see a power increase.

Really?
Title: Re: Recardo graph on H20 injection
Post by: NathanStewart on March 11, 2009, 07:11:16 PM
Really.
Title: Re: Recardo graph on H20 injection
Post by: Milwaukee Midget on March 11, 2009, 08:35:49 PM
Quote
I really doubt if water injection can be of any help on a full pop racing engine.
 

On a naturally aspirated motor you're probably right but forced induction applications almost always see a power increase.

Quote
Water injection is used to lower the temperature of the mixture to avoid detonation.

Actually, water is resistant to combustion (obviously) and you could even say that water has an infinite octane rating.  Add in something that doesn't burn but does absorb a lot of heat energy and you effectively reduce the combustion rate of your air/fuel mixture.  It's a "heat sink" if you will that helps to control combustion and not just cool the mixture directly.

Thanks for the topic - it raises a question.  Detonation aside, if water (only) is injected upstream of a properly designed air box (or into a scoop?) on a normally aspirated engine, can one expect a cooled air charge upstream of the carb/throttle body, and thus, a corresponding increase in density of the air/fuel mixture filling the cylinders? 

Chris 
Title: Re: Recardo graph on H20 injection
Post by: jl222 on March 11, 2009, 09:18:48 PM
The fuel was 87 octane.

The octane rating is a measure of the resistance of gasoline to detonation (engine knocking) in spark-ignition internal combustion engines.

If the same test had been done with 119 octane racing fuel there may have been no difference with water injection. I really doubt if water injection can be of any help on a full pop racing engine.

Water injection is used to lower the temperature of the mixture to avoid detonation. If detonation is limiting horsepower, there are other ways to prevent it. At the limits of racing engines I doubt if water would allow more horsepower to be achieved.




       What water injection does [on supercharged engines] is lower the temperature of the boosted compressed air. This shrinks the air allowing more air in the cylinder. This lower temps allowes one to increase boost and make more power. WW2
AERO engines used water injection [anti detonation injection or ADI] to do exactly this and they had 115/145 octane gas and intercoolers. In the South Pacific when fresh water was short they used salt water!! Thats how important it was.
  As i've stated in another post, Formula 1 teams used water injection untill they invented their [rocket fuel] the water injection system weighed around 35lbs so the new fuel was a big advantage.
 The engines that would benefit the most are roots blowers on gas with no intercoolers.
 I'am not sure what the diesel tractor pullers [John Deer] type are doing these days, but at one point when they went to three stages [they had two turbos blowing into another turbo blowing into another] they had no room for intercoolers and injected water at 3 gallons min.


           JL222


Title: Re: Recardo graph on H20 injection
Post by: Sumner on March 11, 2009, 10:37:52 PM
............... The engines that would benefit the most are roots blowers on gas with no intercoolers...........

We feel we owe a lot of our success in spite of some of the dumb things we have done to the water injection we got from Snow Performance with Nate's help.  One run to the 5 mile at 232 without having the cooling water turned on and the water temp pegged past 250 from about the 2 convinced me.  We warped the heads, but to not of grenaded the motor was astounding to me.  The same motor with a little freshening and the boost turned up (roots blower) using the water injection helped us move the record to 249+ the following year.  I use to think it was a gimmick, but it has made a believer out of me and if I ever get turbos on my truck I'll have it.

c ya,

Sum
Title: Re: Recardo graph on H20 injection
Post by: Blue on March 15, 2009, 11:18:32 PM
      What water injection does [on supercharged engines] is lower the temperature of the boosted compressed air. This shrinks the air allowing more air in the cylinder. This lower temps allowes one to increase boost and make more power....
OK, we have to also recognize the other big effects of water injection that are equally important, and in some engines, the dominant reasons for using it.

Yes, the water does cool the charge, IF and only IF the water evaporates before it gets to the cylinder. in many WWII aircraft engines, most of the water went into the cylinders in liquid form because of poor atomization.  So charge cooling was not the dominant effect in that era.  It was late in the war that Pratt & Whitney and Curtis-Wright figured out that injecting the air upstream of the compressor would help mechanically vaporize it, but they were more concerned with even distribution to each cylinder.

Whether the water is evaporated or not, once it is in the cylinder it will also do several other things.  First, it cools the piston crown itself as it evaporates.  As HP/in2 of piston area increases, cooling often becomes critical and pistons start to melt.  We've all seen it.  Rings weld, holes melt straight through the crown, etc.  This isn't as common in modern engines (especially imports) that have dedicated cooling oil jetted right at the bottom of the pistons.  As we boost up modern engines, we use TBC's (thermal barrier coatings) to keep the heat flux under control, water is a last resort.  Among other things, proper cooling from whatever combination of oil, TBC, and water prevents pre-ignition.  Pre-ignition is often called detonation, but it is a different effect and cooling the intake charge has a limited effect on it compared to cooling the piston.

Second, water also retards the burn rate of the end gas;  this is detonation prevention equal to cooling the intake.  It is why cooling the intake with water injection has more effect than lowering the   As the flame moves across the piston from the point of ignition, the remaining gasses compress to far higher levels than where the spark went off.  This effectively raises the compression ratio for the end gas and leads to detonation.  Water in the mix slows down the burn rate.  This actually absorbs power early in the burn and reduces engine output.  In exchange, it takes energy out of the end gas burn, often lowering its energy below the threshold for detonation.

Last, and most important for nitrous engines, small amounts of water provide a large increase in the working gas.  "Working gas" is what we call the nitrogen, CO2, H2O, and Argon that makes up the un-burnable atmosphere and the combustion products from the fuel and O2 in the air (more CO2 and H2O).  If there is more heat than the engine can handle, adding water increases the working gas and creates more pressure and less heat from a given amount of combustion.  For this effect to be dominant, the water actually needs to get into the cylinder in liquid form.

When using nitrous, we are adding fuel and oxidizer and not adding anywhere near as much working gas.  This adds heat.  So an engine making a given amount of power with nitrous will run hotter and pre-ignite/detonate/melt sooner than the same engine on boost, all other things being equal.  In the case of nitrous, more than any other, water is an important tool to provide this working gas.

Before it is used, TBC's and proper cooling MUST be used.  Otherwise, water is just a band-aid.  About half of the air racing crowd has finally figured this out, the other half is still burning engines down no matter how much water they use.
Title: Re: Recardo graph on H20 injection
Post by: jl222 on March 27, 2009, 12:40:47 AM
Blue

How much boost are the air racers using these days and can you tell us anything about boost temps before and after intercooler?

  JL222
Title: Re: Recardo graph on H20 injection
Post by: Blue on March 28, 2009, 01:16:59 AM
How much boost are the air racers using these days and can you tell us anything about boost temps before and after intercooler?
Short answer:  no data

Long answer:
The Mustangs vary from "stock" power at around 60" MAP for a low Bronze class racer to ~120" MAP for a transport case, Allison rod equipped engine called in various circles a "Mouse motor".  The 3350 radials are divided into 2 separate classes:  the DC-7 derived race engines used in Rare Bear, Critical Mass (retired), and September Fury; and the 3350-26WD Skyraider engines used in everything else.  The former run 80+" MAP, while the latter are good for far less.  I honestly don't know what the boost levels are on the R-2800 in Czech Mate or the 4360's in Furias and Dreadnaught.  "Stock" R-2800's are supposed to run 53 to 55", but I've heard of higher numbers.  One of the Yaks runs a smaller engine on even less boost and definitely holds the mph/HP edge;  I wish they had money for a hotter engine. 

While many younger tuners will allude to only-we-know-this-and-you-just-don't-know-enough-to-understand "mods", talking to the older engine builders has proved the sad fact that these engines have almost no changes from 50+ years ago other than removing limiters.  They are not equipped with any rational level of instrumentation, modern engine coatings, and still run carburators and 60 year old magnetos.

I'd love to get some data on interstage temperatures, but none of the Unlimiteds run anything but the most rudementary data acquisition.  Most don't even measure the cylinder-to-cylinder differences.  Even worse, the impellers are stock designs from 40 to 75 years ago and have far lower efficiencies than we are used to with modern compressors and turbochargers which are common in LSR.  So the temperatures are probably 10 to 30% higher than we see with modern compressors for a given boost level.  I can't prove this without proper instrumentation, however I have seen the compressor maps from these old engines and their efficiencies are HALF of modern compressors.  You're smart and you know compressor maps, draw your own conclusions.

The engines are so large (1650 to 4360 ci, 138 to 186ci/cylinder) that the water-methanol injection flows are massive;  like 2-3 GPM!  While not a firehose, it is a garden hose and aspiration is challenging.  Most teams inject the water into the compressor inlet to make the compressor aspirate the liquid because they use low pressure pumps.  What this does is scatter a lot of liquid droplets into each intake runner on the radials and simply pee it into the interstage area on the Merlins.

IF (and that's a BIG if...) the water actually evaporates in the compressor, the mass flow of the water displaces the air and less air is actually pulled into the engine.  Some of the water does, the majority goes into the cylinder in droplet form (liquid, not vapor).  This has been evidenced by opening up the upper galley of Merlins after a race and still finding standing water and fuel in the intake manifold.  Puddles.  The tuners who believe that this is normal never get outside of air racing or believe the idiocy that aircraft engines are somehow "different" from all other engines.  They are, they're older.

Be very careful of comparing old data (WWII) with new technology.  Where the water evaporates in the complete engine cycle and how the engine actually uses that latent heat and working gas varies radically.  A proper system would use high pressure injection to vaporize the water-methanol downstream of the compressor.  Done correctly, this increases the density of the downstream charge and provides a drop in pressure on the back side of the compressor, increasing efficiency and "free" boost in the compressor itself.  I have seen an optimum system and it is very different (and superior) vs. what air racers use.  The Sport Class air racers are more progressive, and several are paying attention to aspiration. 
Title: Re: Recardo graph on H20 injection
Post by: maj on April 02, 2009, 05:58:15 PM
My understanding is there is a trade off , cyl temp for density, steam takes up a lot of space..
not sure there is enough temp even with very fine droplet size to get evaporation and pull the heat in a NA engine
Title: Re: Recardo graph on H20 injection
Post by: jl222 on April 22, 2009, 06:13:25 PM

 New Hot Rod has a 5 page article on water injection, water with nitrous - blowers -diesels and na.

    JL222
Title: Re: Recardo graph on H20 injection
Post by: jl222 on May 06, 2009, 12:06:44 AM
 Going over my WW11 engine books I had bvillercr take some fotos to post. One is on water methanol injection [ADI] or anti detonation injection.
 Most interesting to me is their octane rating for gasoline and ADI. They rated their gas with an octane number such as 100 and a performance number which would be the octane number when running rich
such as 130 or 100/130 they also had 115 octane which was 115/145,
  115/145 when used with ADI gave them 115/170.
  knowing this I never used the high price gas at Bville for many years when we had water injection and never had detonation problems and usually 25-33 lbs boost. 250  degrees after the intercooler at 33 lbs

  We use the high price stuff now and no water injection but have a much larger intercooler and lower temps.

   Ok Troy post the article :-D

    JL222
   
Title: Re: Recardo graph on H20 injection
Post by: bvillercr on May 06, 2009, 10:30:51 AM
(http://i162.photobucket.com/albums/t246/bvillercr/text.jpg)
Title: Re: Recardo graph on H20 injection
Post by: Blue on May 09, 2009, 03:18:23 AM
Historical semantics:

"Intercooler" is a charge air cooler between multiple stages of super or turbocharging;

"Aftercooler" is a charge air cooler between one or more super or turbochargers and the engine.

I'm not sure where we crossed over into calling any charge air cooler an "intercooler", but that's now accepted practice.
Title: Re: Recardo graph on H20 injection
Post by: jl222 on May 09, 2009, 01:26:07 PM
Historical semantics:

"Intercooler" is a charge air cooler between multiple stages of super or turbocharging;

"Aftercooler" is a charge air cooler between one or more super or turbochargers and the engine.

I'm not sure where we crossed over into calling any charge air cooler an "intercooler", but that's now accepted practice.

  The merlin had water passages between stages that they circulated to keep the whole blower assembly cooler.
 Bvillercr said he would take a foto after we finished the 222 car and got it loaded for El Mirage [he just showed up got to get going on car].

  I never heard of an intercooler untill the 1980s after drag racing an owning supercharged engines since 1956.

      JL222
 
Title: Re: Recardo graph on H20 injection
Post by: jl222 on May 21, 2009, 02:41:31 AM
 One cool thing about last weekend at elmo is we pitted next to Bob Button and the unlimited air racing mustang'' Vodoo'' big rig. Of course I had to ask about the engine.

  160 in of boost, thats about 65 lbs psi  :-o No intercooler and only one impeller [not 2 stageing it] and lots of ADI [water-methanol injection]

  At 65 lbs of boost my charts show 570 degree temp at 65% efficiency on a 70 degree day coming out of the blower that should evaporate a lot of adi :-P

  Bob bought Seth Hammond's modified roadster and he and their crew are fun guys.

   JL222
Title: Re: Recardo graph on H20 injection
Post by: Tom Simon on July 16, 2009, 04:10:30 PM
I am putting a real simple water injection unit (that I experiemented with 25 years ago) on a stock '65 VW bus. No racecar, the VW is bone stock and burns regular 87 octane pump gas. The goal is to cooler temps while running the poor little thing at 4200rpm for 30hrs straight (during the upcoming Vancouver to Ensenada "Beetleball 24" Rally race, we are entered in the stock bus class) Anyhow, I should have something to report with respect to cylinder head and oil temps, but no dyno other than 'seat of the pants'.

One mechinism that I has not been mentioned is water turing to steam in the combution chamber... water expands what, an order of magnatude by volume when it changes state (liquid to gas). If done right, by happenstance or on purpose, that expanding steam could translate to an increase in power in an ICE engine (normally aspirated or supercharged), couldn't it?

Getting really far out there...  if we could just get the hydrogen to separate out from the oxygen, then into hydrogen's smaller components, duterium and tritium, get the cylinder pressure to about one million bar or so, you'd might get a small fussion event inside your engine with each pulse! The good news is you wouldn't even need another fuel (other than water) The bad news is you'd need a stronger engine just to keep the heads on and the rods in it!  :-o

Sorry... the science geek in me just had to go there  :oops:
Title: Re: Recardo graph on H20 injection
Post by: Stan Back on July 16, 2009, 06:10:06 PM
I don't know how to research it -- but years ago there was reference on this site to Bruce Crower's newly-invented (and patented?) 6-stroke combustion engine that relates to what you said.  Fascinating article.  His health in recent years may have contributed to his on-going research.  Someone help us out?

Stan Back
Title: Re: Recardo graph on H20 injection
Post by: 4-barrel Mike on July 16, 2009, 07:00:06 PM
Jack D said: 

   Re: Hayabusa Engines in Car Classes
« Reply #60 on: July 30, 2007, 08:13:30 PM » Quote 

--------------------------------------------------------------------------------
Look up Bruce Crower's 6 cycle diesel that uses the exhaust heat with water to extract the additional power that water to steam can provide in an otherwise idle cylinder.
Consider the expansion rate of water to steam and see if otherwise waisted heat might be useful.
It is proposed to be a High School project for next school year using one of My RX7s.
Several truck engine builders are interested in his patent.


http://www.google.com/search?hl=en&q=bruce+crower+diesel+patent (http://www.google.com/search?hl=en&q=bruce+crower+diesel+patent)

Mike
 
 
 
Title: Re: Recardo graph on H20 injection
Post by: Tom Simon on July 20, 2009, 05:16:32 PM
One possible power adding mechinism that I has not been mentioned is water turing to steam in the combution chamber... water expands what, an order of magnatude by volume when it changes state (liquid to gas). If done right, by happenstance or on purpose, that expanding steam could translate to an increase in power in an ICE engine (normally aspirated or supercharged), couldn't it?

I was thinking along the lines of water acting both as a buffer (that maybe cools and stabilizes the burn somewhat, but takes power away), and a small power adder at the same time. Takes some power away early in the burn, but adds power late in the burn through expansion into steam. 

I'm no chemist, but I think there is something going on at the molecule level where a small amount of water raises resistance to detonation (raises octane).

About 8 months ago, I attended a project update, where these computer modlers are working on better understanding combution were reporting back to their sponsor. They are coming up with a predictive (computer) code to model the combustion event inside the combustion chamber. Their goal is to first better understand the multi-faceted internal burn, model statified charge, pressure wave propagation and a whole bunch of other stuff I barely understood. Then use that information to better control things like cam, ignition, injection timing and duration to keep an engine right at the edge of detonation. Sort of ultra-lean burn for fuel economy. The same thing could help racers, which is why I took the time to listen to the talk.

'You can't control it if you don't understand it'