cottoneg

Sorry, I am off on a tangent. The post on gas for a 1969 got me thinking about water injection. I do not need it now with my new motor. But I remember researching it when I had the original 350/350 with 11:1 compression ratio.

My friend who is a pilot, mentioned air craft have used it successfully for years. I know Edelbrock had a unit, but it those that tried it said it never worked correctly. Did anyone ever come out with a good water injection unit.

7T1vette

Water injected into a high compression engine assists in creating a better 'burn' process during combustion. It has the 'side effect' of increasing power, as a result. WWII [piston-powered] aircraft used this to advantage during take-offs and when max power was required.

I don't know a lot about it, but think you have to be in the 11+:1, or higher, compression ratio and some really high octane fuel, for water injection to even be of any benefit at all. It would probably be more applicable to an engine which is supercharged, turbo-charged, or uses nitrous.

Now, if you are "inventive" and come up with an operational system that will allow present-day vehicles to have 12.5:1 compression and burn 93 octane fuel effectively, you could make a lot of money.

7t9l82

water injection has much potential, and even on a lower compression engine with a little extra Timing it is helpful. but be careful.

U17

We used water injection on larger radial engines... R2800's... 2800 cu.in. 2500hp ...It would add 350hp on a normal 2150hp,R2800... It was only used for higher weight take-offs.. It improved cooling and combustion...And allowed more manifold pressure ect.... It is made up of 49.5% water, not tap water...49.5% alcohol and 1% fish oil...

Bugman Jeff

What you need is a little teeny carburetor for the water system so the engine will only injest as much water as it needs for a given speed/load. Way back in the day my Dad made a simple system that was just a hose from the water tank into the manifold with a fish tank regulator as the (manually operated) valve. Once up to speed on the highway, he'd open the valve and adjust until the car "felt" best. Very crude, but it was good for a few MPG anyway

TOM B1

Many years a go I hade water injection on my 74 pickup.
It was a Ford F250 with a 390 and I installed a custom turbo.
The water injection worked great.
Today you can do better by adding a methenal injection kit sold by Summit racing and others, just add windshield washer fluid for a COOL charge and add about 75 horses also!

Vette5.5

I used water injection on a few cars years ago, before higher octane fuel was availible. Actually one car still has it on, but not sure if the controllers working. Really just going with higher octane fuel now, even if needing some racing gas mixed in. Keep in mind, if your foots in it a lot, the water/maybe alcohol tanks going to empty out pretty quick.

billla

It's intended to match a power-adder...not really practical for daily driving.

Bugman Jeff

Out of curiosity, for those of you who've used it, you mention that you can run out fo water pretty quickly. I assume you still use more gas than water. What's the approximate ratio of fuel injected to water injected? Thanks for the info.

Vette5.5

Really no answer to this one, as depend's on what size water injection nozzle you're using. The systems I've used had tanks less than a gallon. When having a little street fun, dont last very long between fill ups. Some guys in our road track group have highly boosted turbo 4 cyl cars, and filling the water tank after every 20 minute session.

Ironcross

Hilborn injection nozzles screwed into a carb base plate fed on demand with a electric fuel pump could spray any type of compatible fuel into the intake...have to be below the carb to prevent a vacuum leak......cheap NOS type of system......

Faster Rat

Another old timer!
My dad flew "The Hump" in WWII and told me they used to inject ethylene glycol at high altitude over the Himalayas. I believe the engines were supercharged and the anti-freeze was used to keep the cylinder head temps down, especially as the mixtures were leaned out to extend the range. They carried 55 gallon drums of fuel for the Flying Tiger P40s in China. When I was in the Navy during the Viet Nam years, I flew on many radial-engined planes (C54s, C118s, S2s and P2s) but never heard of any of them using any kind of injection.

larrywalk

I am using an old Spearco Water Injection unit on my 406 SBC with 11.5:1 compression ratio. Based on 1/4 mile speeds, it's about 550 hp flywheel naturally aspirated. The system uses a vacuum switch which I've set to 6" Hg to turn on when the vacuum drops below this value (near full throttle), and an electronic control unit which initiates at approximately 1700 rpm and increases the water flow as rpm increases. I've had no problem with knocking when using this system.

The injection fluid is held in a plastic reservoir with a small pump (like used for a windshield washer system). Rather than using water, I use blue windshield washer fluid for the injection fluid (about 40% methanol and the remainder water). And, when I added this Spearco system to my '78 which is used mainly for low and high speed NCCC events, I simply used the existing windshield washing reservoir and pump - the pump is now controlled by the Spearco control unit, and the fluid was re-plumbed to squirt into the carburetor primaries.

I find that for a day's worth of track events, it uses about a half tank of WSW fluid. Of course, no fluid is used for cruising on the highway since vacuum runs at 17 to 19" Hg at highway speeds. Just check it daily and you'll be fine.

I've used this system with engines having 11:1 CRs for about 30 years and have had no problems with it, although I did add a small plastic back-flow check valve in the line to ensure that fluid delivery had no lag due to back flow back to the reservoir.

Vette5.5

Thank's for that, as the Spearco's what I still have on one of my cars with the red tank. Is this company still around, or goners. Just know after a night of street racing, the tank was going down pretty quick. Gotta look, as think I still have the manual and a couple nozzle's laying around somewhere.

Ralphbf

Years ago I played around with water injection.

We simply hooked it up to a Carb. port that didn't have vacuum at idle.
Used an aquarium air stone in a quart of water.

As crude as this sounds it got rid of the ping when accelerating.

It will also clean all the carbon out of the combustion chamber.

There are different size stones to play with.
for $10 bucks it fun to play with, and it does work.

There was a guy selling platinum injection units.
is was a liquid solution and he used basically the same system.
Just a different liquid.

Ralph

U17

I'm not a "old timer"... yet... I was just lucky to grow up around those great planes ... Then flew airshows,freight ect in them... And like old cars you work on them often !!!

cottoneg

I could understand adding alcohol for aircraft, to keep the water from freezing at high altitudes. Unless the weather is below freezing, why would you add alcohol and fish oil?

I did not know Spearco made a water injection unit. If guys with high compression engines are having trouble finding good gas and have issues with detonation, why would more people not use water injection?

U17

More complete burn and lube.....

Bugman Jeff

Alcohol also vaporizes faster, cooling the intake charge faster.

mtcyclon

Water injection has come a long way since the old systems. Snow performance has several kits using computer control for flow settings. Arent electronics great!?