Brings back old memories...

Way back in the early 1980's I used to have a 1970 Torino Cobra fastback with a 429CJ that I was dumb enough to rebuild the engine with 12:1 compression ratio. It ran wonderful on 100LL but that was impractical and it pinged pretty good under loads on premium gasoline. I installed a Shelby Spearco water injection system and it actually worked really well. I ran a 50/50 mix of distilled water and methanol and had a throttle position switch that turned on the pump for wide open throttle, plus a push button on the side of the gearshift T-handle for on-demand operations. It didn't take much spray volume to stop the pinging either, a 2 gallon reservoir would last me almost a week of daily driving as long as I kept my right foot light (hard to do for a 19-20 yr old college kid back in those days).

Back when I had this car and installed the water injection system, one of my father's buddies who flew bombers for the Air Force during WW-II and thru the early '50's commented that they experimented with water injection system on the big supercharged radial engines back then.
 
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Quote.... Soldan told us the system could be made available for Experimental aircraft if there's sufficient interest.

Weight of the system is estimated to be about 42 pounds for a single-engine airplane, including a full tank of fluid. As of early 2013, Air Plains said a single-engine ADI system would be priced at about $9000 and a twin around $11,000. For more, see AirPlains.com or call 800-752-8481.....end

This is not complex enough to pay that much for it here in the experimental world. I expect to see a system for RV use to show up here at VAF for under $500.00

BTW..... It sure would eliminate carbon build up on the piston, head and valve.
 
I did a calculation...

...and determined that for water/methanol mix at 2.11/gal, the owners of big twins with high octane requirements would pay for an $11,000 certificated system from AirPlains in about 220 flying hours. My number were based on ~35 gph and the current AirNav difference between MoGas and 100LL of $1.40/gal.

One would think that is a pretty attractive ROI to the guys that statistically represent 20% of the GA aircraft and 80% of 100LL use. Planes like that probably fly over 200 hours/year.

I wrote an e-mail to AvWeb suggesting that they need to do more follow-up - did not get a response. This is a proven solution. I have a friend who worked for the original Frontier Airlines as an A&P 35 - 40 years ago. They had DC-3s with water/methanol injection systems.

It seems like a win-win situation for everyone. The rich guys save money, we get MoGas at every field and 100LL goes away naturally. Seems like MoGas prices might even come down if it became the fuel of choice.

Larry Tompkins
N544WB -6A
W52 Battle Ground, WA
 
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I wonder how this would affect erosion or corrosion and making TBO. Bet there's some shorter valve life and maybe some piston issues over time.

Dave
 
gasman said:
Weight of the system is estimated to be about 42 pounds for a single-engine airplane, including a full tank of fluid. As of early 2013, Air Plains said a single-engine ADI system would be priced at about $9000 and a twin around $11,000. For more, see AirPlains.com or call 800-752-8481.....end

This is not complex enough to pay that much for it here in the experimental world. I expect to see a system for RV use to show up here at VAF for under $500.00
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Really quite laughable it would cost that much. It can be done for under $200. The only time it is needed is at full throttle. All one needs is a tank, needle valve, a fuel pump, and and injector with some sort of ball check valve in it.

Does anyone have a formula for the required amount of water/methanol given a particular fuel burn?
 
I suspect Ross may know a thing or two about this---------or anyone else who plays around with the fast guys at Reno.
 
A surplus fuel injection nozzle, an electric Facet pump, a needle valve to choke it down a bit, and you're done. With a little extra effort you could create the automatic interface to turn it on at specific manifold pressure and CHT points.

I'm running 8.5:1 compression so this is a spectator sport for me.
 
For those running 8:1 or less, which is probably 80% or more of all Rvs,
you don't have to buy anything, 91 Octane mogas works just fine.
No fear of detonation as long as you keep your temperatures in check,
a smart thing to do wether you use 100LL or 91 Octane.
I am aware that water/methanol injection works but why complicate things when you don't need to.
 
rocketbob said:
Really quite laughable it would cost that much. It can be done for under $200. The only time it is needed is at full throttle. All one needs is a tank, needle valve, a fuel pump, and and injector with some sort of ball check valve in it.

Does anyone have a formula for the required amount of water/methanol given a particular fuel burn?
Click to expand...

Yes Bob, but my estimate included the electronics to read MP and temp to control automatically.

Look here.... http://www.snowperformance.net/stage-2-boost-cooler-n-a.html already packaged.
 
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Just thinking... but wouldn't it be cool if the experimental EFIS/EMS makers all put some general purpose switched outputs on their EMS systems which could be triggered by setting up some user-programmable logic in the configs where you could input by a series of:

when
{parameter name}(logic operation){value}
{boolean operation}
{parameter name}(logic operation){value}
{boolean operation}
{parameter name}(logic operation){value}
{boolean operation}
{parameter name}(logic operation){value}
etc
...
{then perform function = turn general switched output #3 on}

You could then do stuff like automatically turn on relay to power up a water injection pump when a combination of conditions are happening, or do lots of other conditional things.
 
caveman easy!

If I can do it, anyone can. You can build up a system for about $125 (low pressure), or for high pressure, the cost goes up a bit (more expensive pump).

High pressure atomizes better, so using a needle valve to set the flow (reduce pressure) will actually do harm to what you want. That being said, I saw no operational difference between the good ol' ShurFlo pump (Harbor Freight) and the super-duper 200PSI unit (AEM). The Air Plains unit uses a 6PSI fuel pump as its supply, with 2 nozzles. Maybe one of those tiny Facet pump would work?

I am running the smallest nozzle I could find (.016), and it turns out to be just right for my setups (either pump). I have a 6 gal tank (Reno, ya know), but normal flying would call for a 2 gal tank for most ops. X-CY might complicate matters, tho straight water works OK too, if it's not below 32F.

I use the spray during racing, of course. Normal use also is during climb, right AFTER takeoff. I can lean about 2-3GPH depending on altitude, and during this time I'm using the spray instead of a rich mixture.

SAFETY POINT: I do not activate the system until I am established in the climb - I saw one racer crash on takeoff @ Reno due to his system (set for race power) flooding his engine out at about 50AGL. Bad juju.

How it works: I watch the EGTs drop off, and then lean to bring 'em back to where they started. Piece o cake - caveman simple.

My system is pilot operated, tho a 25"MP switch might do the trick - I would not wait for 400F CHTs to show up before the spray would come on. I would still worry about flooding the engine on takeoff with a 25"MP switch...

Buy tanks here: http://www.flambeaufluids.com/multi-purpose/multi_purpose_tanks_overview.html
Buy pumps, filters, and nozzles here:http://www.aemelectronics.com/water...engines-51/?osCsid=eaa8l2bmop5teaidifgq258le2

If you buy a ShurFlo pump from Harbor Freight, be sure it is a recirculating type with a pressure switch.

Nyla-flow line will work aft of the firewall; use alum line fwd please.

The injector(s) should be fwd of the fuel controller - not where it might be subject to vacuum. I have made nozzles out of misting systems (same .016 size), and also got 'em from AEM - no difference in operational aspects. The AEM nozzle is higher quality, with a check valve. The misting nozzles (brass w/SS inserts) are $3 ea.

Get a switch from Home Depot or Lowe's. I think an "ADI ON" indicator light is a good idea.

The alky is actually optional if the OAT is OK for water, and you have an FI fuel system. If you have a carb, or it's c-c-c-cold, use the alky to eliminate carb icing and frozen ADI in the tank.

ADI flow rate should be 10 to 15% of the best power fuel flow; my ADI flow is around 2-2.5GPH. That would work with a 540, and maybe a 390, but I'd look for less flow with a 360, and certainly a 320. Maybe a bleed orfice in a return line would work?

NOTE: 'best power fuel flow' is NOT the normal ~200ROP you see in normal WOT ops. Best power mixture @ WOT would put you in the Red Zone rather quickly, draining your wallet even quicker. So, if your normal takeoff FF is ~25GPH or so, best power would be closer to 21 or 22GPH. AT least, this is the FF difference I see system off vs on. YMMV.

Another positive is that you can run your ignition timing a bit more aggressive too, if cruise CHTs will allow it. I added 2.5 degrees.

It's easy stuff, and yes I can run MOGAS if I want. E10 runs fine too. Do not store E10 for more than 30 days if possible.

Roll-your-own alky: buy some E85, and add water to it in a glass jar (clear 1.75L liquor jugs work fine). The gas floats to the top, where you can pour it off. You end up with the perfect alky/water ratio when finished, but it smells like bourbon when you hit the switch. Methanol is available in 55 gal drums for about $2.75/gal if you look around. Use distilled, or rain water - NOT regular faucet water. Denatured alcohol will also work, but it's expensive.

ADI mixtures are expressed in weight ratios; Water is 8.5lbs/gal; alky is 6.5lbs/gal. 30% alky is fine for our expected MP settings - the Germans in WW2 called this mix EW30. They also has EW50, MW30, and MW50. MW of course means methanol/water. The allies used similar fluids.

BTW: ADI controls CHT AND OT, and can be sprayed on the oil cooler.

Questions?

Carry on!
Mark
 
Mogas'ers

Mark is correct!
Just some R&D testing:
Meth / Water injection, I have done some testing on the dyno. I used a Snow Performance injection system to start with and R&D other sources. The Shur-flow pump is heavy and has a 10 ? 13amp draw @ 200psi. The Snow nozzles will provide a good atomization @ high pressure, however poor at low. I have tested and used misters/ nozzles that are used for deck/patio link: http://www.aeromist.com/mist-nozzles.html A 3-series BMW windshield washer pump out-put is about 40psi and weighs a few ounces and has a low amp draw 1 to 1.3amps. 2 of these pumps in series will produce about 70psi. Board one day and I did some full power dyno pulls back to back with Conaco pump gas (91 octane) and 100LL to see the difference, if any. The power was about the same @ 100%. Mogas burned a lot cleaner according to the wide band sensors. More data needs to be accumulated on multiple Mogas pulls with different configs.
Question:
Mogas?ers, what configs would you like to see run in the test cell, I?m open to suggestions for different set-ups on Mogas dyno pulls.
 
Since you ask

I would like to see exactly when and where detonation occurs
Using 91 octane mogas.
My nonscientific testing shows no detonation occurs in my
NA IO 540 with 8:1 .
I don't really want to find detonation but in my limited tests
210 F oil temp ,hot engine,OAT 101F full power maximum
Climb out to 10000 feet , max cylinder temp 380 and
No detonation detected as per data dump from EI engine monitor.
So, at what point do we need water injection to keep detonation in check?
 
I'm curious about relative low RPM, full throttle and leaning. AKA, the "red box". On a stock -360 with 8.5:1 pistons running 91 octane pump gas. 2500rpm, full throttle and lean. Try again at 2400rpm, 2300rpm, maybe 2200rpm.

It's not too far out of the ordinary, and will show how much detonation margin is left.
 
I'm with Bob & David;
87 octane and 8.5:1. This is the most advantageous fuel, and the most common compression ratio.
The greatest number of pilots/planes would be informed, helping the topic 'take off'. Once that happens, other engine and fuel combinations will naturally follow.
With fuel prices expected to rise alarmingly, this is a good topic. :eek:
 
I'd certainly be interested in this scenario, knowing the detonation limits on 87mogas, I might be going from 91 octane to 87 octane.


I'm with Bob & David;
87 octane and 8.5:1. This is the most advantageous fuel, and the most common compression ratio.
The greatest number of pilots/planes would be informed, helping the topic 'take off'. Once that happens, other engine and fuel combinations will naturally follow.
With fuel prices expected to rise alarmingly, this is a good topic.
Click to expand...
 
I suspect the way one can make 87 mogas detonate is only at relatively low RPMs (2300) and high manifold pressure (27+).
 
That would be my guess.


suspect the way one can make 87 mogas detonate is only at relatively low RPMs (2300) and high manifold pressure (27+).
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Plus hot cylinders.

Using a low-octane gasoline whose ignition temperature is too low causes pre-ignition. Low-octane automotive gasoline (87-octane) has a typical ignition temperature of 300 degrees Celsius; high-octane (93-octane) automotive gasoline has a typical ignition temperature of 400 degrees Celsius. Aviation gasoline is blended to ignite at 500 degrees Celsius. High compression and high cylinder temperature will cause the fuel to ignite before the sparkplug fires.
Click to expand...

I would be really great to find out exactly where or what combination of engine parameters present the limits for detonation.
 
Flambeau Windshield Washer tank

I have been following this thread with great curiosity. I see on the Flambeau tank site Mark referenced that they make tanks with integral windshield washer pumps. Also noted that Thomas has used a BMW windshiled washer pump.

Do either of you two think the Flambeau Windshield Washer tank w/ pump would be worth pursuing? Just looking for a way to avoid reinventing the wheel.

Larry Tompkins
N544WB -6A
W52 Battle Ground, WA
 
Reno racer ADI

I was the Crew Chief for the Reno Racer that crashed when the ADI flooded the engine. I was not there that year and had retired from the crew earlier and moved to Independence.

The Questair Venture "Bad Intentions" had a twin turbos, intercoolers, ADI and water spray cooling. It ran at about 3000 rpm at over 65" boost producing somewhere around 750 HP. Fuel was controlled by a SDS injection system, the first and only use to date of Ross's system at Reno. ADI was a Devils Own controller pumping fluid into 6 locations in the induction air system. Top speed per telemetry data, was over 450MPH.

Needless to say, the engine would not last one second if the ADI shut off at full power, so we spent a lot of time making sure it was adequate. We did not have sponsors, so we were a relatively low cost effort. The Devils Own system worked well in our application. We turned it on at around 40" boost and the flow increased as boost went up. Unfortunately, because of the pump they use, it has a minimum flow of around 7 gph. We could easily reduce the fuel flow with the SDS system by the appropriate amount when the ADI came on so the transition was smooth. The minimum flow would be an issue with the ideas being discussed in this thread. The more alky injected, the smoother the engine ran.

The crash was because the pilot armed the ADI on takeoff, not a normal procedure, and then went too far with the throttle on takeoff and got the ADI going. He was going over gear speed and rapidly reduced boost below the ADI point, but the ADI does not shut off immediately and the motor flooded and shut down. It did not clear before he hit the ground, but the fuel flows and ignition were normal (per the engine data) the entire time.

There is a lesson in that, someone pointed it out in a post.
 
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