Water Injection to prevent Detonation!

Hi all,

Does anyone here have experience with either the Edelbrock Vara-Jection or Holley Water Injection systems?  I have just started researching the usage and found the information very useful.  These systems were used to eliminate detonation when gas made a change to lower octane levels for emissions standards.  Today, the turbo/ supercharger guys use water injection it for the same purpose when running high boost to keep the mixture from detonation.  The water injection system is also said to increase mileage and power, but in naturally aspirated engines running high compression, I would sway more toward the idea the running your timing to the motors original specifications is where the power comes from, rather than running less timing to accommodate the lower octane to somehow cheat the detonation which still occurs.  If anyone has done this, please let us all know because this would be a great way to run the higher compression motors at full timing without the over-heating issues.  Many people on the net claim that it works with amazing results. BTW:  I just bought a brand new Edelbrock Vara-Jection kit still in the box for $60 at a garage sale.  Hmmmm....


Some basic history on water injection that I found from another web site:

The essential idea was developed in the first decade of the last century. The original purpose was enhanced cooling. By 1910 some engines which had been water-cooled were simply produced without water-jackets after addition of 'internal cooling', as water-injection was first called. Those engines had compression ratios around 4:1 and the phenomenon of pre ignition (knocking, pinking) was unknown. Later however this became the main reason for water injection which turns out to give spectacular octane improvement, allowing CR as high as 13:1. By the end of World War II many aero engines used water-injection. German versions used water-methanol mixtures, partly because straight water would freeze in winter. The Wright Cyclone, a main U.S. aero engine, tested with water and methanol-water (the two liquids being miscible in all proportions, unlike methanol & petrol), showed 50:50 best (as had the Germans). The results were summarised as "high savings in fuel cost - 52% at 100% power, decreasing to 25% at low cruise powers... pure water is approximately equal to fuel when used as an engine internal coolant at high power". Water gained the Corsair (flown by some Kiwi pilots in the Pacific) 350 bhp on its normal maximum of 2100 bhp - a 17% increase. These were supercharged engines, so the results may not translate readily to normal aspiration. Another alcohol, infamous ethanol, was similarly mixed with water before injection, but was not as good.

When Renault attacked Formula 1 with twin turbos cramming several atmospheres of boost into Gordini's 1500 cc V6, they readily achieved 450 bhp, but burned holes in pistons. Then a Kiwi mechanic recalled water-injection; a reliable 550 bhp won the championship. The Saab turbo works rally car at one period had a water tank as big as the petrol tank. Some modern gas-turbine aero engines use water-injection for maximum power at takeoff. Various naval and rail external-combustion rigs are improved by steam injection.  
1969 Custom S

Hey Guys,

Nobody has tried this?  Pontiacman8 and Barneyformula, you guys must know something about hooking up water injection... what do you think?  
1969 Custom S

just curious...    are you using it for racing??? or street????

there have also been vapor injection systems..  that use a canning jar... a multi turn needle valve.. a short section of hose and a fish tank bubbler...    a vacuum hose attached to a ported venturi vacuum source...  would lower the pressure in the bottle..  with the air coming into the bottle.. limited by an almost closed needle valve and its flow run through the short section with the bubbler at the bottom...   the vacuum hose is at the top and pulls air from above the water in the bottle...
the problem with this system..  trying to find a ported vacuum source on the carb.. that feeds both sides evenly..

i have seen people build tiny tubing that is routed into the venturi to pull the supply the vacuum to pull the vapors out and into the motor...


there have also been steam injection systems..  with little curved tanks hose clamped to the exhaust pipe...   so the faster you drive the more heat.. the faster the water turns to steam..  it was run again to a tube device above the venturis..


there is a lot of reading to ***  and on some of the systems.. you need a significant amount of water.. or alcohol and water..

with todays cheep high pressure wand type washers...  one might be able to rig up actual fuel injectors to spray water in... at selected times...  there are detonation sensor displays...  so you could trigger it with  signals from that.. if you are creative...


it is really really.. important to use a 2 or 3 wire oil pressure switch to control the systems... as most are activated by  a vacuum switch...   when the engine is not running...  there will be no vacuum.. so the system may fill the motor with water... it has happened dozens of times before...


the oil pressure switch will cut off the water pump when the engine stops and the oil pressure drops


it all depends on what you are planning on doing..

i bet that there are some smokey books on it..


there have also been a few tries at supercooling the intake charge with various freons...  let loose from a small high pressure liquid tank.. into a large low pressure tank...   still a closed system.. between runs.. it is pumped back to the high pressure liquid side ...  since you only need a few seconds of cooling during the burn out and 10 to 12 for the run...  i am counting the time the motor is run up during staging...  as to not give away actual ET's/// then you might know who is doing it.. i don't know if they are still keeping it quiet..???     they are also using a hydraulic accumulator to maintain the pressure on the high side liquid tank...   works so much better with an even pressure there..  

I am going to set this up for the 67 GTO for full time use.  The Edelbrock Vara-Jection set-up uses sensors for vacuum pressure and RPMs from the coil negative.  It comes with a tank, pump, harness, programmable box and the squirters for 2 barrel or 4 barrel set-ups. It has 3 stages of use for different scenarios.  In my case, I am running OK until I WOT, then I may flash detonate on occasion and although I am not sure of this, I will not know until I take it to a speed shop dyno- but I suspect that I am.  This will sense the WOT, and inject the water vapor through the carb intake and cool the charge and eliminate the detonation. The Holley system works approximately the same way through vacuum sensors, and I am searching for that set-up as well for some experimentation with my MG Midget which has a 32/36 DGV and some speed mods.  I will post my results when I complete the tests on a weekend when I have time to do the installation.  I will also try to take photos.

Lou  
1969 Custom S

hmm...

how about installing a detonation sensor on the side of the block...   and using the matching display to trigger the water injection...      or just having it.. for fine tuning..  i have always wondered if the alert levels of detonation were adjustable as to when it turned on the light..?? over background engine noise...  

the vacuum switches are adjustable....  so you will also need to set up a temporary rack of vacuum gauges to monitor things while setting up...

the large hand held fuel pump vacuum gauges are cheep and not hard to rack mount... just for testing.. mount several on a temp panel... one for ported vacuum  one for manifold vacuum... if your carb has a ported vacuum port...

i take it that you are also running vacuum advance...     have you backed off some of the advance to see if it reduces the knock...    you might also want to hook up a vacuum gauge to the advance line.. to see what thats doing..

you could always rig up a cam corder to record the gauges... while you drive...  a poor mans data recorder...



just a thought...  

Sorry, I've never tried water injection, never needed it or knew anyone who needed it. I imagine Edelbrock has fully researched and engineered their system. There is a long history of using water injection, as we've already read and it is a proven method of controlling detonation and increasing power. That's about all I can add....
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

The lack of response to your post may be because most old Pontiac lovers have spent so much time trying to keep water out of their engines and avoid sensors. I don't mean that in a condesending way at all - it may be something we've all been missing out on and didn't even know it. Wayne the Brain seems to have some good solid  suggestions. Please keep us posted on the progress - it seems like an interesting project and good luck.
Brazil  

Guys,

Thanks for all of the input.  It is greatly appreciated.  I posted some pictures of the water injection kit in my readers rides section under the 67 GTO page if anyone was interested in the parts used before I actually get into the installation.

Lou  
1969 Custom S