DIY_EFI Digest Saturday, 14 September 1996 Volume 01 : Number 273 In this issue: Re: Radial- Diametral Head RE: Altitude Compensation Re: MAP sensor Re: MAP sensor Re[2]: archive search; was Re[2]: Re[2]: O2 Sensor-Leaded gas RE: Altitude Compensation RE: MAP sensor Re: Radial- Diametral Head RE: Altitude Compensation re: Electronic Ignition MISC sensors Vats last word Math Question Map Sensors Re: Math Question RE: Altitude Compensation re: RE: Altitude Compensation Re: Math Question See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: dave.williams@xxx.us (Dave Williams) Date: Fri, 13 Sep 1996 07:17:00 +0000 Subject: Re: Radial- Diametral Head - -> Have a look Zoche aerodiesel web page: - -> http://193.26.97.194 Maybe this will be the future of car diesel - -> also! I have some a 1940s engineering book which makes a strong case for the aviation Diesel. Higher efficiency, Diesel fuel lighter than avgas, less chance of fire in crash situations, etc. It probably would have happened, at least for civilian aircraft, if not for the turboprop and turbojet engines, which used basically the same fuel and were smaller and more reliable than piston engines. ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Fri, 13 Sep 1996 07:49:32 -0500 Subject: RE: Altitude Compensation >On Thu, 12 Sep 1996, tom cloud wrote: >> what do i know ?? As I understand: the ratio of O2 and N2 are >> the same at any altitude us puny homo saps (I know, speak for my- >> self) can survive at (oops, poor english). And on the same day, James Weiler replied: >Absolutely ! and don't let anyone else tell you any different ! It's the >partial presures of each gas constituent that decrease with higher >altitude but the ratios of the gases stay the same. If they were >different how would it stay that way over time?? There is a law called >Brownian motion that dictates that all molecules will proceed from a >place of high concentration to a place of low concentration until they >are equally distributed. This is our atmosphere and it's had lots of >time to equilibrate. To which, I reply replied "And I thought Brownian movement was when those little girls are selling cookies." tom ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Fri, 13 Sep 1996 08:19:55 -0500 Subject: Re: MAP sensor >> I would like to add MAP sensing to my system. What's a good MAP to use, >> how much is it, where does one get it (if it's for a vehicle, I suppose >> a parts house), and how does it work? Alex Cazin replied: >The Ford EEC-IV MAP sensor is a good one. It is a "smart" sensor, >with on-board signal processing and it has digital output, a "near" >perfect square wave (49-51 % duty cycle). It is rugged and it lives >well in the engine compartment and a long vacuum hose from the >intake manifold does not bother it. > >Square wave output makes it easy to process. Output frequency is from >about 159 Hz at 0 in. vacuum (key ON, engine OFF or wide open >throttle, same as baro pressure output) to around 102 Hz at 21 in. >vacuum (idle). > >Frequency vs. vacuum output is pretty linear for a good sensor. > Thanks, Alex. Now, I'll just need to find out how much it costs, what it looks like, how it mounts, etc. To followers of the thread, Todd Knighton recently posted: "Newark Electronics has the Motorola Sensors. They're not to be put in "the engine compartment. They're not ruggedized. We've been putting "them inside the Motronics unit inside the car and they've worked well. "the MPX4250A is a 2.5 bar absolute sensor, so it's good to about 20psi "and absolute vacuum. They make a MPX4100A, I think that's the number, "for normally aspirated vehicles, never ordered that one. These are all "temperature trimmed and compensated sensors so they aren't affected by "different temps like most MAPs are." The data sheets for these are on the Motorola web page, (http://motserv.indirect.com/) and they're listed in the Newark catalog for about $26. They have a linear voltage output (not freq), are small and have different methods for connecting them to the pressure source to be measured (probably via a hose). Now, which to use -- and what does one do with the data re EFI ?? The analog output might be ideal for me to augment the control on the Holley aftermarket system I already have. For a digital system, will simply A-D. Now, the frequency output of the OEM unit -- seems that that would entail either an F-V convertor and then A-D or an interrupt driven timer circuit that would return a number of counts proportional to the period of the sensor output. Any suggestions? Tom ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Fri, 13 Sep 1996 08:41:30 -0500 Subject: Re: MAP sensor >How does it work: To be honest I don't understand the chemistry of how a >signal is generated proportional to the pressure that is exerted on the >sensor. I do know that the MAP output is in Hz Pressure sensors are commonly made using a diaphragm as one plate of a capacitor -- when pressure is exerted on it, the capacitance changes. The easiest way to read capacitance is to make it part of an L-C tank or an R-C network in an oscillator. Then, changes in capacitance cause a change in the frequency of oscillation, which can be directly related to the pressure on the diaphragm. Then, if one side of the diaphragm has a vacuum on it, the output is considered 'absolute' (PSIA). If it is exposed to the ambient atmospheric pressure, it is called 'gauge' (PSIG). Of course, these terms apply to any type pressure sensor -- i.e. whether the reading is absolute or gauge. ------------------------------ From: Johnny Date: Fri, 13 Sep 1996 08:10:51 -0700 Subject: Re[2]: archive search; was Re[2]: Re[2]: O2 Sensor-Leaded gas Jeeez, I go away for a couple weeks on vacation and I get back and someone has changed the furniture around on me again. No problem reaching the US site... still wondering what the problem is going south though? Thanks for setting up the archive. - -j- At [Fri, 13 Sep 96 15:26:47 ] dzorde@xxx.au wrote: dzorde> dzorde> Sorry John, clarification. It is Andrew's site that is un-reachable, dzorde> yours works fine. dzorde> dzorde> Dan dzorde@xxx.au dzorde> dzorde> dzorde> ______________________________ Reply Separator _________________________________ dzorde> Subject: archive search; was Re[2]: Re[2]: O2 Sensor-Leaded gas dzorde> Author: diy_efi@xxx.edu at INTERNET dzorde> Date: 9/13/96 2:36 PM dzorde> dzorde> dzorde> -------- dzorde> dzorde> |That's great for those that can get to the web site. I still seem to dzorde> |have a problem connecting to it. dzorde> dzorde> Are we talking about the same web site? dzorde> dzorde> http://efi332.eng.ohio-state.edu dzorde> dzorde> Not Andrew's site. Andrew tried to mirror his site here, but apparently dzorde> he has the same problem we have going the other way. dzorde> dzorde> If you really can not ftp or telnet to OSU's efi332, I would like to dzorde> know about it. dzorde> dzorde> John S Gwynne dzorde> Gwynne.1@xxx.edu dzorde> _______________________________________________________________________________ dzorde> T h e O h i o - S t a t e U n i v e r s i t y dzorde> ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA dzorde> Telephone: (614) 292-7981 * Fax: (614) 292-7297 dzorde> ------------------------------------------------------------------------------- dzorde> dzorde> dzorde> ------------------------------ From: Mark Pitts Date: Fri, 13 Sep 1996 16:40:32 +-200 Subject: RE: Altitude Compensation And I thought BM was just a technical description of my pool playing... = Oh well. But seriously... I agree oil and vinegar make salad dressing, but it = does need to be shaken to get the relevant flavour, and if you dont = shake the atmosphere, it tends to separate. Not a lot, but it does, and = the light fractions float. Mark =20 - ---------- From: tom cloud[SMTP:cloud@xxx.edu] Sent: Friday, September 13, 1996 2:50 PM To: diy_efi@xxx.edu Subject: RE: Altitude Compensation >On Thu, 12 Sep 1996, tom cloud wrote: >> what do i know ?? As I understand: the ratio of O2 and N2 are >> the same at any altitude us puny homo saps (I know, speak for my- >> self) can survive at (oops, poor english). And on the same day, James Weiler replied: >Absolutely ! and don't let anyone else tell you any different ! It's = the=20 >partial presures of each gas constituent that decrease with higher=20 >altitude but the ratios of the gases stay the same. If they were=20 >different how would it stay that way over time?? There is a law called = >Brownian motion that dictates that all molecules will proceed from a=20 >place of high concentration to a place of low concentration until they=20 >are equally distributed. This is our atmosphere and it's had lots of=20 >time to equilibrate. =20 To which, I reply replied "And I thought Brownian movement was when those little girls are selling cookies." tom ------------------------------ From: Mark Pitts Date: Fri, 13 Sep 1996 17:43:45 +-200 Subject: RE: MAP sensor Just a note: The sensors you are talking about have a nipple for a push fit hose, or = two nipples in the case of the differential ones. If you want to get a = pipe thro' a metal box (shielding or whatever), look at the tank = fittings for model airplanes... they are handy, especially the bulkhead = ones with a threaded bit in the middle and a nipple on each end, so that = you can build a box with all the local electronics inside, and not have = to open it t connect/disconnect the pressure hose. Just an idea Mark - ---------- From: tom cloud[SMTP:cloud@xxx.edu] Sent: Friday, September 13, 1996 3:20 PM To: diy_efi@xxx.edu Subject: Re: MAP sensor >> I would like to add MAP sensing to my system. What's a good MAP to = use, >> how much is it, where does one get it (if it's for a vehicle, I = suppose >> a parts house), and how does it work? Alex Cazin replied: >The Ford EEC-IV MAP sensor is a good one. It is a "smart" sensor,=20 >with on-board signal processing and it has digital output, a "near"=20 >perfect square wave (49-51 % duty cycle). It is rugged and it lives=20 >well in the engine compartment and a long vacuum hose from the=20 >intake manifold does not bother it. > >Square wave output makes it easy to process. Output frequency is from=20 >about 159 Hz at 0 in. vacuum (key ON, engine OFF or wide open=20 >throttle, same as baro pressure output) to around 102 Hz at 21 in.=20 >vacuum (idle). > >Frequency vs. vacuum output is pretty linear for a good sensor. > Thanks, Alex. Now, I'll just need to find out how much it costs, what it looks like, how it mounts, etc. To followers of the thread, Todd Knighton recently posted: "Newark Electronics has the Motorola Sensors. They're not to be put in "the engine compartment. They're not ruggedized. We've been putting "them inside the Motronics unit inside the car and they've worked well.=20 "the MPX4250A is a 2.5 bar absolute sensor, so it's good to about 20psi "and absolute vacuum. They make a MPX4100A, I think that's the number, "for normally aspirated vehicles, never ordered that one. These are all "temperature trimmed and compensated sensors so they aren't affected by "different temps like most MAPs are." The data sheets for these are on the Motorola web page, (http://motserv.indirect.com/) and they're listed in the Newark catalog for about $26. They have a linear voltage output (not freq), are small and have different methods for connecting them to the pressure source to be measured (probably via a hose). Now, which to use -- and what does one do with the data re EFI ?? The analog output might be ideal for me to augment the control on the Holley aftermarket system I already have. For a digital system, will simply A-D. Now, the frequency output of the OEM unit -- seems that that would entail either an F-V convertor and then A-D or an interrupt driven timer circuit that would return a number of counts proportional to the period of the sensor output. Any suggestions? Tom ------------------------------ From: "Robert J. Harris" Date: Fri, 13 Sep 1996 09:36:58 -0700 Subject: Re: Radial- Diametral Head Remember the Reichstag - ---------- > From: Dave Williams > To: diy_efi@xxx.edu > Subject: Re: Radial- Diametral Head > Date: Friday, September 13, 1996 12:17 AM > > > -> Have a look Zoche aerodiesel web page: > -> http://193.26.97.194 Maybe this will be the future of car diesel > -> also! > > I have some a 1940s engineering book which makes a strong case for the > aviation Diesel. Just prior to the end of W.W.II, Napier Deltic built the "ultimate IC engine. It was a 12 cylinder horizontally opposed 2 cycle diesel with 2 stage supercharging, inter and after cooling, the exhaust was compounded and the excess was funneled into a nozzle to develop 750 foot pounds thrust. It developed about 3500 HP and weighed less, thus breaking the 1 hp per pound barrier. Problem was the gas turbine could make similar power, much lower weight and much simpler, so the IC engine was relegated to cheap, low power apps and exists today in ac use only because the lawyers have made it impossible to change anything without a billion $ lawsuit. ------------------------------ From: Chuck Tomlinson Date: Fri, 13 Sep 1996 12:52:38 -0400 Subject: RE: Altitude Compensation Mark Pitts wrote: > >But seriously... I agree oil and vinegar make salad dressing, but it does need to be shaken to get the relevant flavour, and if you dont shake the atmosphere, it tends to separate. Not a lot, but it does, and the light fractions float. Near the ground, the atmosphere *is* shaken (and stirred) by convection currents. The fact that air temp near the surface (<20,000') decreases with increasing altitude *guarantees* constant convective mixing. Convection mixes the air vertically, and winds mix the air horizontally. Up above 60,000' there are layers of the atmosphere that do not have a significant vertical temperature gradient. Convective mixing is minimal there, but my car won't run at that altitude :-) Where we live and drive, the mole fraction of oxygen in air is constant at about 21%. - -- Chuck Tomlinson ------------------------------ From: MSargent@xxx. Sargent) Date: Fri, 13 Sep 1996 12:54:02 +0100 Subject: re: Electronic Ignition > Transistor and CD systems only use the points for switching an electronic > circuit. There is no 'real' inductance attached to the points any- > more -- therefore no real need for a cap. In fact, the cap will > slow down the rise/fall of the signal, so it really should NOT be there. When I converted my boat from points to an MSD ignition, the tech folks at MSD said that the cap can be left in place with no ill effects. +--------------------------------------------------------------------------+ | Michael F. Sargent | Net: msargent@xxx.com | Phone: 1(613)721-0902 | | Gallium Software Inc.| | FAX: 1(613)721-1278 | +--------------------------------------------------------------------------+ ------------------------------ From: peter paul fenske Date: Fri, 13 Sep 1996 08:48:15 -0700 Subject: MISC sensors HI ALL With the interest in Map sensors will try and dig out data sheets For the ford the following in. (HG) kpa Hz 0 0 159 3 10.2 150 6 20.3 141 9 30.5 133 12 40.6 125 15 50.8 117 18 61.0 109 21 71.7 102 24 81.3 95 27 91.5 88 30 101.6 80 The gm Map sensor stamped #460 is similiar but has a analog output. 20 KPa gives about 0.9 volt, with 101 kpa about 4.9 volts. Readily available. sorry but the spec sheet is at work. Will post it later GL : peter ------------------------------ From: peter paul fenske Date: Fri, 13 Sep 1996 08:59:04 -0700 Subject: Vats last word Hiya ALL For the people with lots of resistors here are the VATS resistor values 1, 400 ohms 2, 525 ohms 3, 680 ohms 4, 885 ohms 5, 1,130 ohms 6, 1,465 ohms 7, 1,860 ohms 8, 2,360 ohms 9, 3025 ohms 10, 3,730 ohms 11, 4,750 ohms 12, 6,050 ohms 13, 7,500 ohms 14, 9,540 ohms 15, 11,790 ohms This should let the dedicated DIY er do it to Passkey I It doesn't really help anyone else since it would probably take a while Later: peter ------------------------------ From: "Robert J. Harris" Date: Fri, 13 Sep 1996 10:45:06 -0700 Subject: Math Question Given A. 600 PSI pressure from TDC to BDC B. Any piston diameter C. Any stroke D. any RPM you chose Whats the peak torque and HP possible? Not a trick question, just use any numbers you chose. 600 PSI is the pressure of little old fashioned saturated steam at about 440 degrees f. Raise the temp to 900 with super heat and you get 1200 PSI. These are commercial production steam plant values. For extra credit, look up and plug in the PSI values for the temperatures actually present at combustion. Velocity does not matter - don't even think about it. Consider the RPM limit to be whatever the physical destruction flyapart limit is of your engine. Steam will make 20,000 miles an hour plus because thats what shoves the shuttle into space. Still clueless? What is the result of burning pure liquid oxygen and pure liquid hydrogen with no nitrogen, carbon or other contaminants present? After thinking about the numbers, you can begin to understand the fascination with water fuel blends, injections, mixs, and what ever and why,from since the dawn of the Internal Combustion engine, engineers and experimenters keep coming back to it and not just as an anti-detontant. And for practical applications about how much power is truly available from a small piston, check out the last generation of railroad steam engines. A couple of smallish pistons (displacement compared to the multiple diesel engines that replaced them) moving slowly (thinks tens to a couple hundred rpm max) drove 700,000 LB plus locomotives to speeds over a hundred miles an hour dragging loads of up to 10,000 tons behind them - depending on the speed. It took 3 or 4 1500 HP diesels to replace them and they still didn't quite make the power. And by the way, the peak steam pressure on road locomotives seldom exceeded 300 PSI!!!!!! Remember the Reichstag - ---------- ------------------------------ From: peter paul fenske Date: Fri, 13 Sep 1996 10:34:45 -0700 Subject: Map Sensors HI All FYI the part number for the GM Map sensor is 2503679 . Stamped near the connector is the number 460. This was used in GM applications from 1984 to 1992 so should be common in wrecking yards. Uses three conn. GND, + 5V, and signal. Let me know if you want the pinout. The part number for the Baro sensor is 1600683, stamped 833. Recognized by a piece of foam on the pressure port. Here is cal data for baro. 100 Kpa, 4.9V 90 Kpa, 4.4V 80 Kpa, 3.8V 70 Kpa, 3.3V 60 Kpa, 2.7V 50 Kpa, 2.2V 40 Kpa, 1.7V 30 Kpa, 1.1V 20 Kpa, 0.6V 10 Kpa, 0.3V Check these carefully, seem to remember they might be for the Map. It is relatively easy to make a cal chart using a Mytec tester. GL: peter I"ll put out more sensor info but its at work right now. ------------------------------ From: Chuck Tomlinson Date: Fri, 13 Sep 1996 15:33:34 -0400 Subject: Re: Math Question Robert J. Harris wrote: > >And for practical applications about how much power is truly available >from a small piston, check out the last generation of railroad steam >engines. A couple of smallish pistons (displacement compared to the >multiple diesel engines that replaced them) moving slowly (thinks tens to >a couple hundred rpm max) drove 700,000 LB plus locomotives to speeds >over a hundred miles an hour dragging loads of up to 10,000 tons behind >them - depending on the speed. It took 3 or 4 1500 HP diesels to replace >them and they still didn't quite make the power. And by the way, the peak >steam pressure on road locomotives seldom exceeded 300 PSI!!!!!! If steam engines are so great, why were they replaced with diesels? ------------------------------ From: "David M Parrish" Date: Fri, 13 Sep 1996 16:02:59 +0000 Subject: RE: Altitude Compensation >From: cloud@xxx.edu (tom cloud) > "And I thought Brownian movement was when those little girls are selling > cookies." Well, you certainly diffused that situation. - --- David Parrish Pun-ishmnet is it's own reward. ------------------------------ From: SRavet@xxx.com Date: Fri, 13 Sep 96 16:49:10 CDT Subject: re: RE: Altitude Compensation "David M Parrish" Wrote: | | >From: cloud@xxx.edu (tom cloud) | | > "And I thought Brownian movement was when those little girls are selling | > cookies." | | Well, you certainly diffused that situation. I like puns, but that one made me groan! Steve Ravet sravet@xxx.com Baby you're a genius when it comes to cooking up some chili sauce... ------------------------------ From: "Robert J. Harris" Date: Fri, 13 Sep 1996 20:48:51 -0700 Subject: Re: Math Question Remember the Reichstag - ---------- > From: Chuck Tomlinson > To: diy_efi@xxx.edu > Subject: Re: Math Question > Date: Friday, September 13, 1996 12:33 PM > If steam engines are so great, why were they replaced with diesels? Cost, size, complexity, labor costs and unions, government policy during WWII and sheer stupidity. An external combustion engine for anything other than large marine or stationary purposes is not economically comparable to an internal combustion. BTW, the worlds land speed record was set in the first years of this century by a STEAM driven vehicle (the Stanley Steamer to be exact) and it was one hell of a lot faster than anything else period. Won't quote how much over a hundred miles an hour it was because some anally retentive person will expend the night trying to correct me. The point was, is, and always will be to try to combine the sheer power of a steam engine with the simplicity of an IC engine. The use of a locomotive was to illustrate the power available from steam and small cylinder's not to spend my life re-hashing ancient history. Do you think that catapilar and others are trying to invent a cheaper fuel? Not f___ng likely. What they want is a more powerful engine without increasing the size and complexity of the current production engines. And for those that think that pure technical superiority is the sole cause of replacement or change, perhaps you might review the evolution of betamax vs vhs or any other commercial decision made since moby dick was a minnow. ------------------------------ End of DIY_EFI Digest V1 #273 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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