924Board.org

[bruni]

Who has water/methanol injection? what do you think of it, which make or home brew, what are your views on nozzle placement any other comments ?
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1982 931
1975 harley sportster

[ideola]

tuurbo has one from Snow (I think) and Smoothie has a home built version. Lots of posts covering this topic if you search
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erstwhile owner of just about every 924 variant ever made

[tuurbo]

Hi Bruni, Ideola, yes I have a Snow system that puts in about 120 ml/min using two 60 ml/min nozzles, one before the turbo, from the airbox straight into the CIS, and one about 5" from the throttle in the aluminum charge tube. They spray a pretty spectacular, strong burst of mist. It's something one should show a cat, at a distance, just for amusement. The pumps are plentiful so easy to replace.

I use two very fine nozzles to achieve peak atomization. I was unsure of how important atomization was in the equation and took a guess that more was better. So far it's been exceptional.

I have used 90% alcohol 10% distilled water when I've wanted to richen the mix, and have settled on 50% mix now because it is more important to me that I cool the charge. Germany used to have MW50 which contained a few drops of oil.

Unfortunately, I was getting detonation quite early on in the boost phase. I think that it's because the head was reconditioned and shaved. I was getting ping at <1 PSI of boost. Since installing the boost switch properly I've eliminated the ping. The downside is that I use a bit more juice because the pump comes on at <1 PSI. I think I get around 3-5 tanks of gas before I replace the gallon or so (7 litres?) of boost juice. You can feel the car runs like it's intercooled from the moment the boost comes on right up to 10+ PSI.

The next situation, which I'm doing now that the car is off the road, is a second stage of boost juice to kick on at 7 PSI through to 12 PSI. I have a solenoid I can switch on at 7 PSI and run the second 60 ml injector, or a third. I can see room on that aluminum pipe to have four nozzles, if someone wanted it. Two should be enough for me.

I'm sourcing nozzle fittings right now so that I can use maybe a metal hose/plumbing in the engine bay.

The ideal situation is a progressive controller. It can be used with the existing car, or I suppose hooked up to Megasquirt. One of the guys here, I think Min, and others too suggested that you could squirt in methanol and distilled water and even tune it with MS. I think you could get some impressive changes in EGT. For me, I can't do MS right now, but something I'm drawing out in my mind is how one can use individual 'tunnels' with four injector nozzles to spray in with the air directly above the head, without modifying the head. I just don't know right now how I could benefit from doing so without the kind of precise timing you'd get from EFI and electronic injectors.

One thing I've been wondering is this: Does it even make sense to use IAT to measure the effectiveness of methanol and water injection? How do you know you're not measuring the temperature of the liquid medium? Don't EGT measures or O2 signals tell you useful things about how your system is working?
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[bruni]

Hi thanks for that, all good information, I want to fit a system to my 82 turbo which is standard as far as i am aware, however it does ping slightly on full throttle so I intend to fit water injection. I know what you mean about the AIT sensor, however provided it is not directly in the path of the spray nozzle it should be OK. an EGT sensor is a really useful tool but not necessarily on its own, a good indicator of AIT as I believe it is more directly affected by mixture and timing. In an ideal world I would have AIT, EGT, and O2 sensors ++++ but hey I live in the real world
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1982 931
1975 harley sportster

[alexvex]

I've got a coolingmist setup that's going on this week...
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--Alex--
1992 Porsche 968 (VW 2.5L I5 Turbo swap in the works)
1995 Audi 90 Quattro Sport (4.2L V8 Swap)
2010 Touareg TDI
Past Pcars: 80 931, 87 924S, 87 951

[Scorpio]

tuurbo you are the water injection king!
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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

[tuurbo]

lol I'm totally a fan of water and methanol injection Scorp. It's doing everything I'd want an intercooler to do.

Here are some articles I'm using to do a write up on water and methanol injection.

The jump page:

http://www.wwiiaircraftperformance.org/

Detailed Reports on Water Injection

http://www.wwiiaircraftperformance.org/f4f/fm-2-16169.pdf

http://www.wwiiaircraftperformance.org/f4u/kd227.pdf

The R2800 Double Wasp, ThunderBolt, P47, Hellcat, FW-190A, Messerschmitt (e.g., performance improvement was about 10% or 200 HP) and Corsair all used it. Finally, the P-51H was the finest US fighter during the war and it used water injection. I'm sure they needed reliability in battle. So I'm confident of the numbers that came out during that time.

The following shows two figures in each cell. The first set of values in each cell is when water injection is used. Note too that these tests were done using aircraft equipped with intercoolers - it seems they found benefits by using water injection even with an intercooler, and note too that they're not using methanol.



Note that the Time to Climb Height is fully 1 minute earlier at 15,000 ft which would give American pilots a huge gain over aircraft with no water injection. Once you're up higher, you're in a position to attack.

It was also used on commercial aircraft, which is interesting because it's an environment where reliability and timeliness is also very important.

My wife's father worked on the P47 in Europe.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[bruni]

Wow what fantastic documents
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1982 931
1975 harley sportster

[ideola]

Autospeed has a worthwhile series on Water Injection. Starts here:
http://www.autospeed.com/cms/A_110212/article.html
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erstwhile owner of just about every 924 variant ever made

[ideola]

tuurbo, one question that occurs to me about the use of water-alcohol mix is whether the alcohol can cause any detrimental affects to the stock system due to its corrosive nature. Granted, most of the sensitive components are in the fuel delivery system which would be upstream of the water/alc injection point...just a passing thought...
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erstwhile owner of just about every 924 variant ever made

[tuurbo]

[ideola]

Be careful about your assumptions re: old aluminum heads. From my research on E85, all manufacturers have been required by federal law (and the laws of physics) to formulate and treat aluminum engine components so that they are safe with Ethanol-mixed fuels since ... (and here's the key) ... the early 1990s. Our late 70s designed engine components have no such treatment, so the concern over prolonged exposure to any type of alcohol is real. Treatments include flavors of nitriding, anodizing, and powder coating.

Now, having said that, Ethanol is not nearly as corrosive as Methanol (by at least an order of magnitude). Based on what I've seen, Methanol has been proven to be highly corrosive to untreated aluminum. God only knows what grade aluminum is used in our heads and intake tracts. I don't mean to be a fear monger, because I don't know, I can only report on what I've researched. Personally, it gives me pause to think about spraying methanol into the untreated early interior of our intake manifolds. The corrosion, by the way, causes microscopic degradation of the aluminum, which creates issues for both pollution and contamination of the fuel.

As for rubber and nitrile and other components. This is a significant concern. I am convinced that no fuel system should be blindly converted over to ANY concentration of Ethanol (let alone Alcohol or Methanol) without addressing it from head-to-toe. That means from the tank all the way to the combustion chamber. The biggest concern is that the stock rubber seals and the stock rubber and nitrile lines from the fuel pump, within the CIS components, and the fuel injector lines WILL degrade MUCH faster when exposed to higher concentrations of Ethanol, much less more aggressive forms.

I was even contacted by a board member here who works for Shell R&D in the UK and has had significant challenges sourcing components that were compatible with BOTH regular pump gas and ethanol-based mixtures. As I shared with him:

[tuurbo]

Carefulness regarding the assumptions is an issue when using methanol and water injection, just as it is an issue when rejecting the use of methanol and water injection, or supposing that it harms the head or intake.

Have you found any evidence of methanol-water injection ruining someone's aluminum head?

If so, I'll listen.

I haven't yet found evidence of methanol and water injection resulting in aluminum head damage on aircraft or automobiles. Remember, the following are production numbers for each aircraft:

1. P-47C - 57+55+128, nearly 200 aircraft, with no reports of head problems due to methanol injection.
2. Rolls Royce Dart engine in production from 1950 through to 1987 in the following aircraft, without aluminum degradation:

* Armstrong Whitworth AW.660 Argosy medium-range transport (C Mk 1 variant)
* Avro 748 Feeder airliner
* Grumman Gulfstream I Executive/Passenger aircraft
* Breguet Alizé anti-submarine aircraft: Dart RDa 21 1950hp with water/methanol injection
* Fokker F.27 small airliner
* Handley Page Dart Herald small airliner
* Hawker Siddeley Andover military transport
* NAMC YS-11 short/medium range airliner (Japanese Aircraft)
* Some Douglas DC-3 transport aircraft have been upgraded to use Darts. DC-3's in BEA service which received this update were called Pionairs.

3. Rolls Royce Merlin and Griffon - The Merlin used aluminum heads, water jacket, crankcase, the Griffon used an aluminum crankcase, cylinder banks and heads. All made since 1950. Here's the breakdown for the Merlin, for example:

Model V-1650-9
Application All models:
Engine Type V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material Aluminum heads, water jacket, crankcase; Steel cylinder liners; Forged aluminum alloy pistons
Bore x Stroke 5.4" x 6.0"
Compression Ratio 6.00:1
Supercharger type Two stage engine driven supercharger, 12.0" first stage, 10.1" second stage
Supercharger Ratio 6.391 (low blower), 8.095 (high blower)
Anti-detonation 50:50 water-methanol injection anti-detonation injection (ADI)
Fuel System Bendix-Stromberg PD18, Type G-9 pump, 9 psi idling, 12-16 psi operating
Weight 1,690 lbs
Power 1735 bhp @ 3000 rpm 66" boost
Rotation: CCW crankshaft rotation when viewed from supercharger end
Cylinder ID Bank: Right - A, Left - B when viewed from supercharger; "A" has oil regulator; 1-propeller end, 6-supercharger end
Firing Order 1A-6B-4A-3B-2A-5B-6A-1B-3A-4B-5A-2B,
Spark Plug 14mm thread, 0.011-0.014" gap
Magneto BTH C6SE12S/2 (Ex: AN SF 12RG-P-3 or SF 12RA-P-3, In: AN SF 12 LG-P-3 or SF 12LA-P-3)
Northeast (Ex: AN SF 12RA-P-4, In: AN SF 12LA-P-4)
Magneto Direction Exhaust Side -- CW, Intake Side -- CCW, viewed from driving end
Spark timing Fully Advanced: Intake 45° btc, Exhaust 50° btc, Magneto breaker gap 0.011-0.014
Cam Timing
(crank degrees) Intake: Valve opens 31° BTDC, Closes 52° ABDC, 0.015" clearance (cold), 0.590" max lift -- Note: Time w/0.020
Exhaust: Valve opens 72° BBDC, Closes 12° ATDC, 0.020" clearance (cold), 0.590" max lift
263° intake duration, 264° exhaust duration
Note: Tappet clearance for timing -- 0.020"

If you add water to methanol, you have the oxygen required, I should think, for re-oxidization to happen. Even 1% could be enough. I run 50:50.

I'm willing to entertain thoughts of methanol screwing up the aluminum in my 1980 Porsche 931, but I'll worry when I see an empirical case of it.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[ideola]

First, just because one aluminum-based motor used it safely means nothing, unless you have empirical information detailing the grade of aluminum used and any special treatment was given to those materials.

Second, in the absence of empirical evidence, we can make inferences based on what OEM manufacturers are doing. The fact that ALL major OEMs changed their manufacturing process around aluminum-based engines in the early 90s specifically because of the concerns over Ethanol-induced corrosion is enough of a reason to be concerned in my opinion. Multiply that by whatever order of magnitude you want for the increased corrosiveness of Methanol over Ethanol.

Third, yes, I have found empirical evidence of problems systems not designed for Ethanol based fuels. Do some poking around at this site: http://icorr.net/papers.html
While I didn't find anything specific to an aluminum head, this is one of the few sites I found that actually cited scientific studies vs. the usual fear-mongering found on discussion forums.

Bear in mind, Methanol is more aggressive than Ethanol. I'm not a chemist, so the nuances of the impact of water mixtures and whatnot escapes me. But I do know that one of the big concerns over any Ethanol based fuel is its hydroscopic nature, which actually increases the rate corrosion.
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erstwhile owner of just about every 924 variant ever made

[tuurbo]

Yes but Dan, the Merlin is a WWII engine. You said clearly: