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Water Injection for Industrial V-Twins

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Grumpy Cynic
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I think the paper on the effect of droplet size was by the same authors as the one I already posted.
Will try to refresh my memory on this. Stuck inside today due to weather when I should/could be working on tangible things. Not doing good things for my mood...........

Edit:
Pages that won't let me read until I agree to their "cookie policy" aren't helping any.
Next.
 

rv7charlie

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Heh heh...My father ran what was not-uncommon at the time, water 'vapor injection' on 6cyl Studebakers and a '64 Chevelle with a 283" 2 barrel carb. Simple to build: Quart jar with a rigid tube soldered into the lid reaching to the bottom of the jar, and another tube soldered in, barely entering the jar. Needle valve in series with the 2nd tube, feeding a plate under the carb with a port into the side of the plate. Manifold vacuum sucks air into the jar through the long tube, bubbling water in the jar. Moisture rich air flows into the manifold with the fuel mixture. He claimed that he got a couple of mpg better mileage, and increased performance. That was shortly before I started driving, so I never checked the mileage claims for myself. With a carb, vapor flow will decrease when you think you need it most, during hard acceleration or WOT.

Remember, intake plumbing and especially, combustion chamber shape, were really primitive back then. Engines would 'ping' (detonate) with minimal provocation, even with good fuel. Lead and carbon (with attendant hot spots) were a way of life in those engines. I'd be surprised if something like that would have any noticeable positive effect on a modern engine, unless it's been pushed to limits way beyond what's sensible for an aviation engine.

Water injection (engine) - Wikipedia
 

pictsidhe

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If you put the nozzle in carb venturi, flow will be greatest at max airflow. I am hopeful that something like the Chevelle setup, but with a liquid nozzle in the venturi, will meet my needs.
 

Protech Racing

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I raced 500$ endurance cars for 10 years .
I turboed a VW and used water injection triggered by the TPS switch. The position of the injection point was a low pressure point of the intake , just prior to the turbo . The squirter was made from crushed 3/16 steel line soldered shut and drilled with 2. 040 holes. 1 Standard VW windshield washer pump. I still have a couple spares.
It worked fine. Lowered the temp and eliminated detonation . 10# boost max target.

I also used the same pump system onto the front brakes at Sebring . 1 Driver hated the work load of having to turn it off . ( driver was /is a pilot!!) I cut him loose. Total water used was 4 gallons per 2 hrs.

 

Mike0101

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There are good Tech papers from WWII era testing (NACA and others) out there. Keep in mind, the higher the RH (relative humidity), the more you have to lean on pressure to get droplet size down. With smaller droplets you effectively increase surface area, which interns helps with phase change (evaporation). If you don't want distribution issues (cylinder-to-cylinder), small droplets are essential, with that expect 100+ PSI pressure (nozzle size dependent) at a reasonable engine load.

As for the "hypersonic nozzle" that's marketing nonsense (BS), it's the tolerances and materials that are important. It's too small to be a true swirl type.

EDIT - Above refers to induction spraying (same as mentioned hypersonic nozzle)
 
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Geraldc

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In my collection of random objects is a water injection system from about 1958. It consists of a half gallon glass bottle and holder feeding to an alloy grenade shaped metering unit that is fed off a vacuum pipe.
 

pictsidhe

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Oil furnace nozzles are one source for us. The ADI ones being another. The oil burner ones are pretty much standardised. The ADI ones are very variable in quality and specs.
 

Mike0101

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Oil furnace nozzles are one source for us. The ADI ones being another. The oil burner ones are pretty much standardised. The ADI ones are very variable in quality and specs.
See link Nozzle . At the top of the page is the one used by many kits (even on aircraft).
 

pictsidhe

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See link Nozzle . At the top of the page is the one used by many kits (even on aircraft).
Yes, like that. When I needed inexpensive misting nozzles some years ago, I used oil furnace nozzles. Proper water nozzles were horribly pricey. One oil nozzle catalogue actually had information for water use. Flow rate and angle is different. Oil nozzles are $5...
 

karmarepair

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Parsing some of the automotive sites, they suggest water/methanol ratios around 15% of fuel flow, up to 25% , for NA engines. This is to effectively boost octane to allow more advance and compression. I'll have to do some math, but let's say fuel flow for 40 hp is 2 gph. 6-8 ounces per hour of water/methanol should suffice. Half a beer. I'm tired, so go easy on me, but seriously, it's not going to be much. And do you really, when sport Flying, climb at Vy for a **** HOUR? Full throttle climb at low airspeed is when I would want this little bit of help.
 
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pictsidhe

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Parsing some of the automotive sites, they suggest water/methanol ratios around 15% of fuel flow, up to 25% , for NA engines. This is to effectively boost octane to allow more advance and compression. I'll have to do some math, but let's say fuel flow for 40 hp is 2 gph. 6-8 ounces per hour of water/methanol should suffice. Half a beer. I'm tired, so go easy on me, but seriously, it's not going to be much. And do you really, when sport Flying, climb at Vy for a **** HOUR? Full throttle climb at low airspeed is when I would want this little bit of help.
That's for ADI and charge cooling, not engine cooling. Engine cooling will need a lot more.
 

TiPi

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If you are using nozzles without a check valve (non-drip), you will need a solenoid to close off the water otherwise the low pressure in the manifold will keep pulling water through when you don't need to use it. Injecting it before the carburetor or into the venturi increases the likelyhood of carb ice.
Water/methanol is on my list for testing with the test club to see if there is a measurable power gain.
 

Vigilant1

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If we are talking now of using water for more than charge cooling and want power augmentation, maybe nitrous oxide has a place. One switch could open the solenoid to the nitrous bottle, the flowing gas then brings in water and methanol in the right proportion. Methanol for fuel, nitrous for oxygen, and water enough to keep the temps in line while the engine is being flogged hard. Might work, briefly. Simple in one way: no interface with the throttle opening. Everything is in the right ratio automatically.
 
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rv7charlie

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Learning sources and methods is great, but if you're running normally aspirated, what problem are you solving? These engines are designed to run at full throttle, full rpm, at sea level, on the worst gas you can buy, after it's been 'aged' over a winter (or two).

Enhancing octane displaces some of the energy content of the fuel. It worked great 50 years ago in poorly designed combustion chambers, but with today's tech, the problem is almost nonexistent unless the engine is modified to raise combustion pressures a lot (high compression pistons or boost).

I know the mud boat guys and the tractor pull guys are extracting impressive HP from little engines, but they aren't flying them. Putting the engine in an a/c and then pushing it hard enough to need detonation protection seems...counterproductive, at best.

FWIW, the most successful automotive conversions seem to be the ones that change as little as possible from the original engine configuration.The ones that accumulate a lot of hours are the ones that operate well within the original HP specs.
 

Vigilant1

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Power levels above OEM come with an increasing risk of failure. But, for whatever reason, people want to consider /talk about flying with very high specific power.

The VW Type 1 works reliably in acft use at about 175% of the OEM engine--but with entirely new cylinders, heads, rods, pistons, crankshafts, it's truly not the same engine at all. The improved heads go some distance toward allowing better heat rejection than the OEM heads, and the increased displacement comes with increased cylinder area that helps, too. Unless a lot of this is done for industrial engines, and they are refined in flight for a few decades, similar reliability at similar specific power levels is unlikely.
 
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pictsidhe

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I would like extra power for climb. If also prefer not to run very rich. Newer engines have been leaned out to please the EPA, but not the engines.
Cruise will be well inside stock limits.
You've never looked at the head design of these things, have you? I've seen better ports and chambers in 70 year old engines.
 

mcrae0104

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If we are talking now of using water for more than charge cooling and want power augmentation, maybe nitrous oxide has a place.
I believe Rare Bear had a nitrous system at one time. I do not know that it was ever used in a race. I have also heard rumors that some in the F1 class have attempted to sneak a small bottle aboard that could be connected after being closed in. Perhaps @Creighton could shed more light?
 

Protech Racing

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There is a very small power increase with water/meth injection for an NA engine. Probably Not worth the effort IMHO for take off power, unless the engine is just plane weak and needs a lot of help at WOT. . The power increase is partly due to charge cooling and partly due to a very slight increase in cyl pressure. 2-4% total. If you squirt it at cruise , you can use a bit less fuel and still make the same cylinder pressure .
Look up the new BMW water injection .

The cylinder temps will drop a few degrees. Not 50 * maybe 25 on 300* head.
 
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