DIY_EFI Digest Saturday, 26 December 1998 Volume 03 : Number 617 In this issue: misc. gizmos for sale/trade Re: Chemical warfare Re: spiralmax See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Stowe, Ted-SEA" Date: Fri, 25 Dec 1998 09:35:09 -0800 Subject: misc. gizmos for sale/trade hi. I have to clean up my computer/project room to make way for new toys, I thought this stuff might appeal to someone here, throwing it out seems morally wrong. I have a nice 8051 PC from blue earth research, imbedded cmos version, I/O, analog/digital, extra I/O modules, etc. w manuals/software $40.00, rs-232, led driver, etc etc. (works too). Toshiba laptop parts, (nice small HD drives) 1.4 GB HD 814 Mb HD 3 memory modules for a Toshiba laptop 1 8 Mb 1 32 Mb 1 16 Mb all this works, penalties of upgrades. $50.00 for all of the PC parts. a programmable electronic ignition kit, from Jaycar in Australia, model kc5202. unassembled, still in packs, manuals, etc. (adjustable timing, tach drive, etc) $50.00 I could use some GM parts from an '85 sunbird 1.8 or 2.0 liter, engine wiring harness, Coil, distributor, ECU, aldl plug, air cleaner, etc. Thanks, Ted Stowe ------------------------------ From: Chris Conlon Date: Sat, 26 Dec 1998 01:05:58 -0500 Subject: Re: Chemical warfare Hi everyone, Greg wrote: > Here I thought that only code heads did lots of caffeine and > worked real late!! Ahh, but these days writing code is what pays the bills around here. Though come to think of it, late nights have always been a way of life. So here's my Xmas contribution. [reasons for power increase due to water injection] > Don't be forgetting about the increase in net output due to > absorbtion of heat (and consequent reduction in work done) during > the compression stroke. This is something I can understand but that I don't really have a good feel for. I have to admit I've been very lazy about all this and haven't done any of the calculations I should be doing. Yet. My current hope is that high compression work is not a *terribly* bad thing *as long as* your cylinder is insulated well enough that it turns into expansion work a moment later, and not into heat lost into the water jacket. > In the real world, this means > that the first thing to condense on a too cool engine surface will > be rather strongly concentrated, highly corrosive acids. A seriously > water injected engine might burn enough cooler to justify running a > significantly hotter thermostat in order to help avoid acid > condensation! Hmm. I think sulfuric & sufurous acids will be the bigger problem as far as water injection goes. Lean, hot conditions favor NOx, and N2O5 + water is how you make nitric acid. Cooler, richer conditions disfavor NOx, giving you less acids. (Also the BP of nitric is way lower than sulfuric.) The path for sulfuric and/or sulfurous acid production is similar, except that it depends absolutely on the availability of sulfur in the gas, and less so on lean conditions, and still less on hot conditions. I had read that GDI was currently impractical on USA pump gas due to high levels of sulfur... but have no real knowledge of this subject. > I SUSPECT that this phenomenon may be the real root of corrosion > troubles in alky motors, too. Actually, I had meant to ask if anyone knew the exact chemical path by which alcohols were so corrosive to engine parts. I have some vague guesses, but would like to have a real answer. Helene V. wrote: > There is also something I have been wondering, what about the effects > of minerals in water like Ca and Na? You would have to use distilled > or at least demineralized water, right? While I'm sure some people run tap water all day long, personally I'd stick with distilled. It's still way cheaper than the gas that the car uses in the same amount of time. I think Greg pointed out that Ca and Mg will be the big troublemakers, their salts are less soluble than Na or K. Here also sulfuric is more of a problem than nitric, sulfates are often way less soluble than their nitrate equivalents. > Well here I must say that just as with NOx, it is a question of > whether you want to have performance "on motor" or "anything goes". > It flatters my ego more to kick a** on motor and controllers alone > because I know I can do it again and again provided I keep my car > in good tune, whereas this guy is a bit embarrassed when the bottle > peters out or the mixture For me it's less about ego and more about afforability and sustainability, and to a lesser extent crusing range. I want power that the engine can sustain more or less continuously (assuming infintite fuel and other consumables), and I want those consumables to be relatively afforable, say no more than the 2x cost per mile of 93 octane pump gas. I have nitrous, and it's fine for what it is, but it doesn't fit this description. Water injection, OTOH, is fine for me because I'm prepared to treat it just like gas, and fill up every so often. But of course, to each their own. Tom Sharpe wrote: > I agree 100%.I would like to see a discussion of ammonium nitrate > (fertilizer) and ??? injection. Would methanol/ethanol disolve it? > Anything else?? I have some experience with liquid and semisolid explosives using ammonium nitrate (AN) as one of the components. While I'm not gonna say it wouldn't work (cos I'm sure it could be made to work) I'll point out a couple engineering details to consider. AN loves water, and dissolves incredibly well in it, but is much less soluble in nonpolar stuff. Solubility in MeOH or EtOH is so variable with temp that (as a field technique) we would use methanol and ice (or dry ice) to crudely recrystallize AN from all the mud, etc, that it comes mixed with in fertilizer grade AN prills. The blending octane is probably very low, but you probably can't use too much anyway. IMHO it's pretty likely to deposit AN powder residue in various places in your injection nozzles & engine, this will be "bad" if it's let to sit as it will suck water from the air, form metal nitrates, release ammonia, etc. Robert Harris wrote: > Acetone is always an option. What's the octane number of acetone? I'd be scared that it, like most small ketones and aldehydes, would be a strong pro-oxidant and prone to detonation and/or doing nasty things to the insides of your fuel system. But hey, simple theories are so often wrong. Greg wrote: > >Now if water/methanol formed a more stable azeotrope, in some ratio, > >that might give a higher heat of vaporization than either one alone. > > Guessing here, but I bet on them forming the more stable azeotrope--it > takes an awfully big (tall) tower to completely dry out alky, and alky and > H2O have a really high affinity for each other--which is part of why > methanol is such a good fuel tank dryer outer. Yeah, I was thinking of the relative difficulty of drying out small alcohols. (Instead of looking things up like I should). I'm not sure you *want* such a high heat of vaporization unless you really do need the charge cooling. Think the other way - imagine if you could inject liquid freon or particulate dry ice into the cylinder. Since with those materials you would not have to pay the high heat cost of vaporizing water, there'd be more heat "left over" to raise the pressure. But of course water has the 2 unbeatable advantages of being cheap, and not requiring more oxygen to maintain stoich. (Since, except for a monopropellant setup, oxygen is still one of the limits on generating heat and thus power.) But for the sake of something, consider: Ethylene glycol, propylene glycol and glycerol as polyols capable of sucking up a lot of heat of vaporization. Does anyone have octane numbers for these puppies? The headstrong may consider methyl nitrate, ethyl nitrate, and propylene glycol dinitrate. #1 was used as rocket fuel in WWII, and once upon a time I made some, but as I recall it was very liable to detonate with increasing pressure, much more so than nitromethane. ("Under pressure" being anything above atmospheric.) On the plus side it has almost all the oxygen it needs to burn right in the molecule. (Ethylene glycol dinitrate is even more dangerous, it's one step short of nitroglycerin. On the plus side it undergoes exactly stoich self-combustion. I never felt comfortable making more than small amounts of this stuff at once.) "Propylene tri-ol trinitrate" would be nitroglycerin, let's not go there. Propylene glycol dinitrate might even be manageable, but I never had easy access to PG and have never made it. (Note: don't try this at home. But if you do, please put me in your will.) Someone mentioned hydraulic lock. That sure would suck, but it seems to me that this could happen with the fuel even more easily, since a much larger volume is being injected. As for corrosion, etc, many things are solved cos you only inject water under higher loads, and remember to run it at low load long enough to flush the water out nicely. (Like cooldown on a turbo car, or using gasoline to flush out an alcohol engine.) One thing I rarely see mentioned is that the ignition system may need some help with water injection. (My 10 year old stock one is marginal right now, and totally loses it with a 50HP nitrous shot.) Certainly the burn rate will change, which could easily mean you need a new ignition timing curve for optimum power. Unfortunately I don't have any practical info on this. Ok, 'nuff bs from me for tonight. Happy Holidays everyone! Chris ------------------------------ From: Aaron Willis Date: Sat, 26 Dec 1998 00:32:57 -0800 Subject: Re: spiralmax Daniel Peper wrote: > Have any of you guys heard of a product called SpiralMax, its a piece of > metal that has fixed blades on it and you put it inside the intake hose and > it supposedly swirls the air causing a turbocharge type of effect. their > webpage is at http://www.spiralmax.com/ > > I just want to know what you guys think. > > On a second note, I wrote them an email saying I was skeptical, and this is > what I got as a reply, I almost can't believe it. > > "You're young, and you are hard to part with your > money that is the reason why you are so skeptic, it is not that you are > skeptic because you are a scholar or scientist. That category of people > are skeptic of everything, laws of physics and chemistry take a change > every so many years. You are also making assumptions on a subject you > know nothing of, i.e. that you are the most skeptic of all my customers, > what do you know to say that? We have had 100's of thousands of > inquiries, do you know all of them? Your remark is emotional then, as > Spock would say, illogical. Just the facts, is the way to go." > > I think someone needs to work a little more on their customer relation > skills. > > Just for that I probably won't buy the product. Daniel, Holy Turbulence! You made my night. Just when I thought humans were progressing, a bozo like this comes along...first off, to insult a potential customer AND state that the "laws of physics and chemistry take a change every so many years"...unbelievable. But to sell a product like this? Well, they must sell some, as they have a lot of advertising, which isn't cheap. But this thing has to be a joke. I HAVE seen products that are similar for the Harley-Davidson market. They are little brass inserts with blades that are bent so as to impart a spin to the incoming air. The difference is that these are installed AFTER the carburetor, and are intended to improve air/fuel atomization (a noble quest) by tumbling the mixture. I don't see how disturbing "dry" air in an otherwise smooth path can possibly improve the intake charge, especially that far up- stream of the fuel. I will also forward this to an EFI mailing list and see if I can get any input from them. There are some genuine rocket scientists on that list and they might know something we don't. Thanks for a good laugh - Aaron ------------------------------ End of DIY_EFI Digest V3 #617 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".