DIY_EFI Digest Thursday, April 29 1999 Volume 04 : Number 250 In this issue: RE: MC6840 timer specs. Fuel injector choice? Inefficient engines-- Re: Direct Injection Re: Fuel injector choice? RE: multiple O2 sensors Re: MC6840 timer specs. Direct Injection - very simple model cam grinds for SC Re: Help - Pickup Circuit Re: Fuel injection plugs Flame - Not Re: Flame - Not RE: Fuel injector choice? Re: Fuel injection plugs RE: Fuel injector choice? RE: Fuel injector choice? Re: Fuel injection plugs Re: Help - Pickup Circuit Re: Fuel injector choice? Need Fuel Injector Data Re: Fuel injector choice? Re: Fuel injection plugs Re: Need Fuel Injector Data See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 29 Apr 1999 13:12:00 +0200 From: Niinikoski Juha Subject: RE: MC6840 timer specs. Try this one http://mot2.mot-sps.com/cgi-bin/dlsrch Juha > -----Original Message----- > From: Daniel R. Henriksson [SMTP:rotax@xxx.se] > Sent: 29. huhtikuuta 1999 10:28 > To: diy_efi@xxx.edu > Subject: MC6840 timer specs. > > Hi > I need the specs. on the MC6840 timer IC, i've searched around on the net > with no luck, there must be some datasheet pdf's out there... > > (Weber Marelli WD48.08 uses one of those 6840's...) > BR > Daniel Henriksson ------------------------------ Date: Thu, 29 Apr 1999 06:27:57 -0500 From: Thomas Martin Subject: Fuel injector choice? I am starting to gather enough info to PFI my 77 Olds 350 in my 85 Cutlass this summer, and would like some input on what is the better fuel injector to look at. The Multec or Bosch? Or is there another? Is the late 70's Cadillac (Olds) 350 with EFI a port type? Can I modify my factory alum intake (from 82 307) with injector boss's? Or is there any reason to use the stock 77 iron piece instead for PFI? Thanks Thomas Martin ------------------------------ Date: Thu, 29 Apr 1999 07:07:20 -0700 From: "Michael Selig" Subject: Inefficient engines-- Fuel for thought-- - ----- Original Message ----- From: Espen Hilde To: Sent: Thursday, April 29, 1999 1:30 AM Subject: Re: Fuel injection plugs I thought the bennefits from diesel was the fact that its run under full compression during part trottle.making for a compleat and fast burn. The down side is that the exess air is cooling the combustion . a gasoline engine on part trottle is run at low compression (less air) the burn is slower ,we have to try to compensate with more ign.advance, and gets more negative work done and expose the internals of the engine with heat for a longer period.(low rpm, high advance =long time period for negative work) The cars are run at part trottle most of the time :-).......exept from some folks like myself trying to be effective....(scratching my speed itch) We are running ineffichent engines all of us that uses gasoline ,most of the time when we are cruising at part trottle.This is really not acceptable.We are accepting it because at low output the engine is not using that much fuel so a increase is not that much. One way to solwe this is to cut cylinders.Making it possible for the cylinder to operate closer to max torque where its most effective. Espen Hilde ------------------------------ Date: Thu, 29 Apr 1999 07:55:20 -0400 (EDT) From: Pat Ford Subject: Re: Direct Injection Previously, you (William T Wilson) wrote: > On Wed, 28 Apr 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > > > this couln't have possibly worked > > it wasn't simulated on a computer before it was built > > Wonder how they built the first computer then? ;) LOL > > > it's just not possible to make a FI system effeicient without hanging > > a few hundred pounds of miscellaneous wiring and computer chips off it > > Unless you are being facetious, I point you to... every diesel engine made > before the advent of electronic controls? > I think you missed his point - -- Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ Date: Thu, 29 Apr 1999 08:13:50 EDT From: AL8001@xxx.com Subject: Re: Fuel injector choice? In a message dated 99-04-29 07:34:55 EDT, marttj@xxx.com writes: >Is the late 70's Cadillac (Olds) 350 with EFI >a port type? Yes, the rear wheel drive Nova based Caddy Seville with the 350 Olds engine is port FI. The first year front drive Seville/Eldorado, Olds powered _may_ also use port FI. The system uses a Bendix ECU with operation similar to the Bosch D-Jetronic( map sensor). D Jet was popular with VW, Mercedes, SAAB, Volvo. Harold ------------------------------ Date: Thu, 29 Apr 1999 07:40:39 -0500 From: Don.F.Broadus@xxx.com Subject: RE: multiple O2 sensors They are to big to be EGT and are at leaset 2 inches down from the head. > -----Original Message----- > From: Tony Bryant [SMTP:Tony.Bryant@xxx.nz] > Sent: Wednesday, April 28, 1999 8:25 PM > To: diy_efi@xxx.edu > Subject: Re: multiple O2 sensors > > > > Take a look at the JUNE 1999 issue of Chevy High Performance magazine. > On > > page 83 is a photo of John Lingenfelter's 357 cube > > race truck engine. There are O2 sensors in each header tube. Only the > > passenger side is shown but it is likely the driver side header has 4 > > sensors also. Two Holley 750 dominators feed the engine. Pi Research on > > board data acquisition collects all of the sensor data. The article does > not > > reference the O2 sensors and they appear to be at least 3 wire types. > Has > > any one seen this set up before ? > > More likely they'll be EGT probes. > ------------------------------ Date: Thu, 29 Apr 1999 05:56:06 -0700 From: Mike Brown Subject: Re: MC6840 timer specs. Daniel R. Henriksson wrote: > > Hi > I need the specs. on the MC6840 timer IC, i've searched around on the net with no luck, there must be some datasheet pdf's out there... > > (Weber Marelli WD48.08 uses one of those 6840's...) > BR > Daniel Henriksson Daniel, I searched arround also for a data sheet on this part also with out much luck. It is a pretty old part. Finally found a older Hitachi data book and got one from there. I also ordered a set from.... can't remember now from where. Not Motorola, I think from Thompson. Anyhow I do have paper copies for this part if you need them. I got one of these Weber Marelli units in the Edelbrock system I'm running. If you think finding info on this part is tough wait to you get to that PAL right alongside of the 68HC11. There is acouple of other very strange SG parts in there that I had to model to figure out what they are doing. If your unit is the same as mine I do have considerable information on it (hand written schematics and programing info). Good Luck, Mike ------------------------------ Date: Thu, 29 Apr 1999 13:40:47 GMT From: bob@xxx.com (Robert Harris) Subject: Direct Injection - very simple model Middish sized V-8. Use a standard 4 barrel carb manifold. Start with mounting a standard throttle plate from a Holley vacuum secondary ( or other brand ). Connect the primaries to the foot feed. Connect the diesel pump "throttle" to the foot feet. Throw away everything above the throttle plate and plug the non sensor holes in the throttle plate. Basic Stamp or similar computer. Inputs - MAP, air temp, EGO, coolant temp, RPM. throttle position from the diesel injector. Output - stepper motor position for the secondaries. In this scenario, using the primaries tied to the diesel pump, the mixture will vary from rich to pig rich depending on the air flow to pump flow relationships. The computer compensates by adding AIR to the engine ( leaning it out ) from some simple tables and measurements. The EGO fine tunes it. Notice the complete lack of injector timing or pulse widths or cylinder to cylinder stuff. Since the calculation is not time critical in respect to crank angle, the algorithm needs only to loop at some speed necessary to update the single output - stepper motor position - in near real time to the engine. Next observe that the fuel flow LEADS the air flow. The computer is always in catch up mode - leaning the mixture back to set-point after an increase in fuel flow. This natural behavior eliminates any need for computer aided enrichment "accelerator pump" stuff as it is built into the design. Stanameyer makes a number of diesel pumps and injectors for mid range V-8 engines that is compact enough to work well and the older GM units are reasonably available in pre-owned parts palaces. To placement of the injector - an enlarged sparking plug hole. There was a thread about plasma jet ingnition. There is was also one about stratified charge. The model to look at is fuel scavenged prechamber stratified charge. Essentially a small pre-chamber which couples the fuel injection and the sparking plug into a smallish chamber that leads to the main chamber. The fuel is injected past the sparking plug and straight into the main chamber. The prechamber is extremely rich. Since the sparking energy is an order of magnitude or more less in a still chamber, it is extremely easy to get a plasma jet effect. Also, the firing phase of all spark ignitions cares less about the "mixture" at the plug as every thing is stripped below its corporate atoms. The optimum is excess hydrogen from fuel rich conditions as it is the hydrogen atoms after the plasma explosion ( all spark ignitions ) that travel furthest into the "mixture" and initiate the chemical / thermal reaction of the fuel. Don't agree? Argue with John B. Heywood, Director Sloan Automotive Laboratory, M.I.T Internal Combustion Engine Fundamentals, ISBN 0-07-0286-37-x Chapter 9 Combustion in Spark-Ignition Engines - with emphasis on flame jet pre chamber stratified charges. Bought the book and actually read it. >From the above. a mechanical direct injection based on a diesel pump and injectors is not out of the reach of a moderately competent fangler - once you rescrew your hat and think "Control The AIR". Using the GM/Ford diesel pump will force the fuel into the chamber at about 1800 psi and during a relatively small number of crankshaft degrees - about any time you want it. Think vaporization - screw atomization. This also should qualify as a doable in your lifetime DIY_EFI because its not going to work without a simple computer to control the air like conventional EFI controls the fuel. Think about it - its not that hard to do. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Thu, 29 Apr 1999 10:00:59 -0400 From: jsg@xxx.com Subject: cam grinds for SC I'm about to install a Vortech supercharger on my SBC 305 TPI, and I'm thinking about changing cams too. The vortech FAQ has this to say about cams: 4) What is the correct cam to run with my supercharger? Cam selections are best discussed with the various cam manufacturers. Many people select cams which are not the correct choice for centrifugal superchargers. When discussing the cam with a manufacturer make sure they understand a Turbo cam or a cam for a Roots style supercharger is different than a centrifugal cam. Generally speaking the supercharger and the cam do the same thing (increase volumetric efficiency), be cautious of choosing a cam that has large amounts of lift and duration. Ideally for a street application retaining decent idle, emissions and drivability are important, for this reason we suggest a "moderate" camshaft. Given the choice between two cams we suggest the milder of the two for street applications. Of course that is of little help, and I would like some idea of what's going on before contacting manufactures. So, what does make for a good cam for applications like this? How do these cams differ from turbo or roots specific cams? john ------------------------------ Date: Thu, 29 Apr 1999 08:50:17 -0400 From: Barry Tisdale Subject: Re: Help - Pickup Circuit You could fire a one-shot w/ the inductive pickup. A 74121 or 74123 would do it - as far as a circuit diagram goes, probably one of the Radio Shack books would have one. 'Engineer's Notebook' or 'Semiconductor Reference Guide' from RS have sample circuits. I build lots of that stuff. Barry At 09:14 AM 4/29/99 +0200, you wrote: > > > >Hi, Please help, > >I have seen some of the discussions on the subject of Inductive pickups for >spark. > >I have a system where the signal from a inductive pickup is fed into the >mic input of a pc, to count the sparks. > >The problem is that the software gets confused, for every spark puls >consists of a number of pulses that is picked up. > >Can anybody please supply me with a circuit to convert the input to one >single spike per spark ?? > >Thanks Michael. > > > > > ------------------------------ Date: Thu, 29 Apr 1999 10:07:05 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Greg Hermann wrote: > The difference MIGHT be almost this big at part throttle--but the > difference is due mostly to pumping losses, not necessarily to > thermodynamic superiority This was a figure from an automotive engines book I had from an autoshop class. The figure seems to be confirmed by other texts/sources, but they don't detail the conditions under which the engines see this effeciency numbers. > They are really quite close on a volume basis! within 2% or so, with > gasoline a bit ahead. You got me there, according to this site (below) it is exactly 3%. http://www.cs.ruu.nl/wais/html/na-dir/autos/gasoline-faq/part1.html > No--more like it cannot burn all of the oxygen it breathes in, so it cannot > make as much power. As long as the fuel is completely burned, it shouldnt matter should it? Seems like you could have as much oxygen just sitting there as you want, it would just not participate in the reaction. > For a given volume of fuel, a diesel produces roughly twice the > >pressure as a gas engine right? > > Not at all--only place the pressure is higher is at the top of the > compression stroke, prior to ignition/injection. But this is where the reaction occurs and where the temperature and pressure are relevant. In the other 3 strokes, the only thing affecting thermal effeciency is thermal losses. I was speaking in terms of the combustion, a diesel can see 20:1 where a gas engine might only see 10:1. The diesel generates enough pressure and heat to self-ignite the mixture! Do you mean that after/during ignition, the force/pressure generated by a gasoline reaction is greater than a diesel reaction? Why would a diesel produce so much more torque then? > Where you goofed is by just applying pv=nrt. > > The power that you can (ideally) get out of a given amount of gas will > always be limited by the (useful) delta T times the specific heat times the > mass flow. The "useful" delta T is limited by the available expansion > ratio. If the gas is losing heat to the water jacket as it expands, you > will get less than the ideal amount of work out of it. Assuming the same types of thermal losses between the two, the diesel will still retain twice as much heat because of the nearly doubled pressure. Most of the heat of these systems is lost to the water jacket and exhaust system, but at least they can compared given proportianate thermal losses. I used pv=nrt just to find temperature with regard to the volume and pressure of the system, I don't see how it is not applicable (except that we are not dealing with an *ideal* gas). > T1/T2= (P1/P2) exp (0.283) = (V2/V1) exp (0.4) ----These exponents are for > air, and would change somewhat for different gasses. But plenty close > enough to figure out how things work. Likewise--specifc heat varies with > both pressure and temperature, but holding it constant is close enough to > get a GOOD feel for how things work. Q=C(Tf-Ti). I think we need to know the temperatures of the reactions and the heat capacity of gas and diesel to be able to make and assumption. According to the equation, it could vary quite a bit assuming a large temperature difference. > The ideal work out of a power stroke, W = (T1-T2) x (specific heat) x (mass > flow). My physics book defines work as the integral of p*dv, so the work done will be proportional to the expansion ratio. > As you can see from the first equation, (V2/V1) ---the expansion ratio-- > determines how much delta T is possible with a given engine design. > But--since we are talking about RATIOS, a higher absolute T1 allows more > work from a given mass flow at any given expansion ratio. Right, the diesel sees a far greater t1 being that it self-ignites the fuel at this point right? > No, it does not!! > > A diesel sees a higher pressure at the top of its compression stroke than a > spark (Otto) engine does, but then burns its fuel at a nearly CONSTANT > pressure. Because it cannot burn at stoichiometric, and because it burns at > constant pressure, its peak temps are not as high! If it didnt see a higher peak temp, then why would diesel self-ignite? By virtue of the doubled pressure, due to cr, at tdc combined with the combustion reaction the temp would have to be higher. Why would the reaction be a constant pressure reaction? In any case, the pressure would increase during the reaction. > An Otto cycle engine burns its fuel at a nearly constant VOLUME, and at an > approximately stoich a/f ratio--therefore its peak pressure and temperature > go quite a bit higher than a diesel's do!!! This can't be right, "If the volume of a system (such as a gas) is held constant, that system can do no work." That being said, a constant volume reaction would do no net work. > These facts are exactly why an Otto cycle is inherently more efficient than > a diesel cycle!! I think I am missing something here, maybe just my flimsy grasp of the 1st law of thermodynics. But my automotive books do indicate that a diesel has greater thermal efficiency, by virtue of maintaining more of the heat produced. James Ballenger btw, what do you guys have your word wrap set to? Every message I write now seems to come out with the wrong word wrap. ------------------------------ Date: Thu, 29 Apr 1999 14:13:07 GMT From: bob@xxx.com (Robert Harris) Subject: Flame - Not It wasn't supposed to be a flame - just exasperation at the inability of people to understand that what's new and hot - generally is not. Example - name the most modern valve configuration Overhead Valve, Dual Overhead Cam, Valve in block ( flathead ) Correct answer FLATHEAD. It was evolved to reduce the production costs associated with OHV or OHC. Every time you see a "new" engine idea, check with the guy at the patent office. Most likely it was invented during the pre-WW II "racing" era where each major power sponsored outrageous prizes to develop the military technology needed for the coming war. And when national survival is at risk, it inspires a fantastic spurt of development. And please don't draw inferences from the "current" implementation of a specific technology as to what that technology is capable of. I know I come across as cranky and an old pharte at times, but when you small box categorize things, you lose the beauty of using something in ways that expand the mind and solve the problem eloquently. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Thu, 29 Apr 1999 10:56:56 -0400 (EDT) From: "Clive Apps Techno-Logicals 416 510 0020" Subject: Re: Flame - Not > > It wasn't supposed to be a flame - just exasperation at the inability of > people to understand that what's new and hot - generally is not. yeah a lot of that in the auto world other than the elctronic stuff, and some exotic platics most of the tech is more than 50 years old > > Example - name the most modern valve configuration Overhead Valve, Dual > Overhead Cam, Valve in block ( flathead ) OHC was around in the 20s > Correct answer FLATHEAD. It was evolved to reduce the production costs > associated with OHV or OHC. > > Every time you see a "new" engine idea, check with the guy at the patent > office. Most likely it was invented during the pre-WW II "racing" era where > each major power sponsored outrageous prizes to develop the military > technology needed for the coming war. And when national survival is at risk, > it inspires a fantastic spurt of development. yes lots of good stuff in the first few indy type cars > > And please don't draw inferences from the "current" implementation of a > specific technology as to what that technology is capable of. I know I come that was a joke dude I know what all the old stuff is caplable of a well tuned Weber setup is still about as good as most EFI setups for both power and economy d > across as cranky and an old pharte at times, but when you small box categorize > things, you lose the beauty of using something in ways that expand the mind > and solve the problem eloquently. better than a miserable old s**t ttyl Clive ------------------------------ Date: Thu, 29 Apr 1999 10:31:04 -0500 From: Don.F.Broadus@xxx.com Subject: RE: Fuel injector choice? The Olds engine in the caddy is port fuel injected. A 2 bbl TBI is used in the center of the intake. This is your best bet to inject an olds engine. I see these cars at the U-Pull-it all the time, there is not much interest in them so you can grab all you want. You could up grade the ECM to a 165 and batch fire the injectors. The Intake, TBI, injectors, and fuel rail will set you back around $200 at you-pull-it I don't know what type of HEI was used, any late model computer HEI (1982-later) will work. Good luck on this project. I had thought about doing a similar swap on my friends 455 Olds. Don > -----Original Message----- > From: Thomas Martin [SMTP:marttj@xxx.com] > Sent: Thursday, April 29, 1999 6:28 AM > To: diy_efi@xxx.edu > Subject: Fuel injector choice? > > I am starting to gather enough info to PFI my 77 Olds 350 in my 85 Cutlass > this > summer, and would like some input on what is the better fuel injector to > look at. The > Multec or Bosch? Or is there another? Is the late 70's Cadillac (Olds) > 350 with EFI > a port type? Can I modify my factory alum intake (from 82 307) with > injector boss's? > Or is there any reason to use the stock 77 iron piece instead for PFI? > > Thanks > Thomas Martin > > > > ------------------------------ Date: Thu, 29 Apr 1999 11:00:27 -0500 From: steve ravet Subject: Re: Fuel injection plugs > > An Otto cycle engine burns its fuel at a nearly constant VOLUME, and at an > > approximately stoich a/f ratio--therefore its peak pressure and temperature > > go quite a bit higher than a diesel's do!!! > > This can't be right, "If the volume of a system (such as a gas) is held constant, > that system can do no work." That being said, a constant volume reaction would do > no net work. The spark engine burns it's fuel much faster than the diesel engine. It burns fast enough that it's simplified to a constant volume compression because it burns while the size of the combustion chamber is not changing size that much (right around TDC). The volume then changes of course, when the piston moves down under the pressure of the hot burned mixture. That's where the work comes from. The whole cycle isn't constant volume, just the part where the heat is added. The diesel engine injects and burns fuel during the whole power stroke. While the fuel is burning and trying to raise pressure, the piston is moving down and releasing pressure. It's modeled as a constant pressure expansion. - --steve > > > These facts are exactly why an Otto cycle is inherently more efficient than > > a diesel cycle!! > > I think I am missing something here, maybe just my flimsy grasp of the 1st law of > thermodynics. But my automotive books do indicate that a diesel has greater > thermal efficiency, by virtue of maintaining more of the heat produced. > > James Ballenger > > btw, what do you guys have your word wrap set to? Every message I write now seems > to come out with the wrong word wrap. - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ Date: Thu, 29 Apr 1999 15:00:02 -0400 From: Teller.John@xxx.com Subject: RE: Fuel injector choice? Put a 2 bbl TBI from a 350 on a 455? Can that throttle body flow that much air? Or did the caddy come equipped with something else as its power plant? - --- John T. >The Olds engine in the caddy is port fuel injected. A 2 bbl TBI is used in >the center of the intake. This is your best bet to inject an olds engine. I >see these cars at the U-Pull-it all the time, there is not much interest in >them so you can grab all you want. You could up grade the ECM to a 165 and >batch fire the injectors. The Intake, TBI, injectors, and fuel rail will >set you back around $200 at you-pull-it I don't know what type of HEI was >used, any late model computer HEI (1982-later) will work. Good luck on this >project. I had thought about doing a similar swap on my friends 455 Olds. ------------------------------ Date: Thu, 29 Apr 1999 14:12:04 -0700 (PDT) From: Squash Subject: RE: Fuel injector choice? I can't believe the easiest way to EFI an olds or buick or caddy or whatever is to get this old FI system. Just get an intake and mount injectors in the runners. You can have a shop such as force-efi (.com) do all the machinework for you. Costs a bit more, but it sure is nice! - --- Teller.John@xxx.com wrote: > Put a 2 bbl TBI from a 350 on a 455? Can that > throttle body flow that much air? > Or did the caddy come equipped with something else > as its power plant? > > --- John T. > > >The Olds engine in the caddy is port fuel > injected. A 2 bbl TBI is used in > >the center of the intake. This is your best bet to > inject an olds engine. I > >see these cars at the U-Pull-it all the time, there > is not much interest in > >them so you can grab all you want. You could up > grade the ECM to a 165 and > >batch fire the injectors. The Intake, TBI, > injectors, and fuel rail will > >set you back around $200 at you-pull-it I don't > know what type of HEI was > >used, any late model computer HEI (1982-later) will > work. Good luck on this > >project. I had thought about doing a similar swap > on my friends 455 Olds. > > > _________________________________________________________ Do You Yahoo!? Get your free @xxx.com ------------------------------ Date: Thu, 29 Apr 1999 16:00:42 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >> > An Otto cycle engine burns its fuel at a nearly constant VOLUME, and at an >> > approximately stoich a/f ratio--therefore its peak pressure and temperature >> > go quite a bit higher than a diesel's do!!! >> >> This can't be right, "If the volume of a system (such as a gas) is held >>constant, >> that system can do no work." That being said, a constant volume >>reaction would do >> no net work. Thanks for the answer, Steve. I must have missed this post earlier! What I said is most certainly correct, and your have described why rather well. I never said "constant volume expansion, I said constant volume combustion. It is mechanically impossible to inject fuel into a diesel quickly enough to approach the burn rate that an Otto (spark) cycle engine has. > >The spark engine burns it's fuel much faster than the diesel engine. It >burns fast enough that it's simplified to a constant volume compression >because it burns while the size of the combustion chamber is not >changing size that much (right around TDC). The volume then changes of >course, when the piston moves down under the pressure of the hot burned >mixture. That's where the work comes from. The whole cycle isn't >constant volume, just the part where the heat is added. > >The diesel engine injects and burns fuel during the whole power stroke. >While the fuel is burning and trying to raise pressure, the piston is >moving down and releasing pressure. It's modeled as a constant pressure >expansion. > >--steve > >> >> > These facts are exactly why an Otto cycle is inherently more efficient than >> > a diesel cycle!! >> >> I think I am missing something here, maybe just my flimsy grasp of the >>1st law of >> thermodynics. But my automotive books do indicate that a diesel has greater >> thermal efficiency, by virtue of maintaining more of the heat produced. The diesel cycle is less efficient than the Otto--their higher compression (really expansion) ratio brings some of this back. The fact that they have no pumping losses at part throttle is the big one behind why they get better mileage in everyday driving. Regards, Greg ------------------------------ Date: Thu, 29 Apr 1999 18:10:41 -0400 From: "Bruce Plecan" Subject: Re: Help - Pickup Circuit At Radio Shack they have a series of books called something likt Mini Engineers Guide to ----- ----. In one of them, they mention opto-couplers. Use one of these of off the neg side of the coil. No RF to deal with that way Bruce > >I have seen some of the discussions on the subject of Inductive pickups for > >spark. > >I have a system where the signal from a inductive pickup is fed into the > >mic input of a pc, to count the sparks. > >The problem is that the software gets confused, for every spark puls > >consists of a number of pulses that is picked up. > >Can anybody please supply me with a circuit to convert the input to one > >single spike per spark ?? > >Thanks Michael. ------------------------------ Date: Thu, 29 Apr 1999 18:13:00 -0400 From: Frederic Breitwieser Subject: Re: Fuel injector choice? > runners. You can have a shop such as force-efi (.com) > do all the machinework for you. Costs a bit more, but > it sure is nice! Its actually not that difficult to do yourself... either with a proper welder, or a product called durafix. Durafix comes in two flavors, ferrus and non-ferrus, so you can weld steel/iron or brass/copper/aluminum, etc. Its good to about 40,000 psi of pressure if you are a pro, or I'd cut that figure in half. For welding bungs on an intake, its great stuff, nice and fast, and doesn't leave a rotten stink in the room (don't use the product in your living room however). All ya need is a stable surface, a $20 propane torch, and a pair of shop goggles. torch welding products: www.durafix.com My intake (I tig'd it, but it gives you the idea): http://www.xephic.dynip.com/dodge/dodge.html ------------------------------ Date: Thu, 29 Apr 1999 15:56:23 -0700 From: "Gerald B. Clark" Subject: Need Fuel Injector Data This is a multi-part message in MIME format. - ------=_NextPart_000_008B_01BE9258.D5499820 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit A friend of mine and I are working on an unusual project. We are adapting a '93 Saturn ECM and two DIS modules to run a Continental O-200 aircraft engine. The engine is 200 C.I. (3.3 L) 4 cylinder dual plug and should make about 120 HP at about 2800 RPM. Unfortunately, the fellow who chose the Saturn ECM and specified the fuel injectors died. We have tried two different sets of fuel injectors and neither seem to work right. The first set was apparently way too large. They were the Rochester p/n 17104988 which flow about 72 LB./hr. and 2 Ohm. We felt that they were going to be too big when we started. Next we tried a set of Rochester p/n 17102119 that are rated at 19 LB./hr and 16 Ohm. The second set appears to be too small. Part of the problem may be that the ECM has 2 Ohm drivers. We are looking for some data to select the correct injectors for the job. We believe that we need a flow of about 15-19 LB/hr. and 2 Ohm Peak and Hold. The pockets installed will take a type 5 (3 O-ring) injectors. Can anyone supply us with the information or give us an idea of where we can find a chart with the injector data? If someone can suggest a year and model of engine using the correct injectors for us, we could go to the dealer and buy them. If anyone needs 4 of the Rochester 17104988 injectors which we believe are for the LT-1 Corvette, we would like to find a new owner. The injectors have about 30 minutes running time on them. Jerry Clark (K7KZ) http://www.AZStarNet.com/~gbclark PGP key http://pgpkeys.mit.edu:11371/pks/lookup?op=get&search=0x30FD11E5 - ------=_NextPart_000_008B_01BE9258.D5499820 Content-Type: image/jpeg; name="Notebook.jpg" Content-Transfer-Encoding: base64 Content-ID: <008a01be9293$8186de60$8b9dfea9@xxx.com> /9j/4AAQSkZJRgABAgEASABIAAD/7QSyUGhvdG9zaG9wIDMuMAA4QklNA+kAAAAAAHgAAwAAAEgA SAAAAAADBgJS//f/9wMPAlsDRwUoA/wAAgAAAEgASAAAAAAC2AIoAAEAAABkAAAAAQADAwMAAAAB Jw8AAQABAAAAAAAAAAAAAAAAYAgAGQGQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA4 QklNA+0AAAAAABAASAAAAAEAAQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAA4QklNBAoAAAAA AAEAADhCSU0nEAAAAAAACgABAAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEA L2ZmAAEAoZmaAAYAAAAAAAEAMgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklN A/gAAAAAAHAAAP////////////////////////////8D6AAAAAD///////////////////////// ////A+gAAAAA/////////////////////////////wPoAAAAAP////////////////////////// //8D6AAAOEJJTQQAAAAAAAACAAA4QklNBAIAAAAAAAIAADhCSU0ECAAAAAAAEAAAAAEAAAJAAAAC QAAAAAA4QklNBAkAAAAAAqIAAAABAAAAgAAAAAIAAAGAAAADAAAAAoYAGAAB/9j/4AAQSkZJRgAB AgEASABIAAD//gAnRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcKggNC4wAP/uAA5BZG9i ZQBkgAAAAAH/2wCEAAwICAgJCAwJCQwRCwoLERUPDAwPFRgTExUTExgRDAwMDAwMEQwMDAwMDAwM DAwMDAwMDAwMDAwMDAwMDAwMDAwBDQsLDQ4NEA4OEBQODg4UFA4ODg4UEQwMDAwMEREMDAwMDAwR DAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDP/AABEIAAIAgAMBIgACEQEDEQH/3QAEAAj/xAE/ AAABBQEBAQEBAQAAAAAAAAADAAECBAUGBwgJCgsBAAEFAQEBAQEBAAAAAAAAAAEAAgMEBQYHCAkK CxAAAQQBAwIEAgUHBggFAwwzAQACEQMEIRIxBUFRYRMicYEyBhSRobFCIyQVUsFiMzRygtFDByWS U/Dh8WNzNRaisoMmRJNUZEXCo3Q2F9JV4mXys4TD03Xj80YnlKSFtJXE1OT0pbXF1eX1VmZ2hpam tsbW5vY3R1dnd4eXp7fH1+f3EQACAgECBAQDBAUGBwcGBTUBAAIRAyExEgRBUWFxIhMFMoGRFKGx QiPBUtHwMyRi4XKCkkNTFWNzNPElBhaisoMHJjXC0kSTVKMXZEVVNnRl4vKzhMPTdePzRpSkhbSV xNTk9KW1xdXl9VZmdoaWprbG1ub2JzdHV2d3h5ent8f/2gAMAwEAAhEDEQA/APROif0Kv6X81T9L j+ar/m/5K0F8rJJIfqlJfKySKn6pSXyskkp+qUl8rJJKfqlJfKySSn6pSXyskkp+qUl8rJJKfqlJ fKySSn//2ThCSU0EBgAAAAAABwABAAAAAQEA//4AJ0ZpbGUgd3JpdHRlbiBieSBBZG9iZSBQaG90 b3Nob3CoIDQuMAD/7gAOQWRvYmUAZIAAAAAB/9sAhAAMCAgNCQ0VDAwVGhQQFBogGxoaGyAiFxcX FxciEQwMDAwMDBEMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMAQ0NDREOERsRERsUDg4OFBQO Dg4OFBEMDAwMDBERDAwMDAwMEQwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAz/wAARCAAYBaAD ASIAAhEBAxEB/90ABABa/8QBPwAAAQUBAQEBAQEAAAAAAAAAAwABAgQFBgcICQoLAQABBQEBAQEB AQAAAAAAAAABAAIDBAUGBwgJCgsQAAEEAQMCBAIFBwYIBQMMMwEAAhEDBCESMQVBUWETInGBMgYU kaGxQiMkFVLBYjM0coLRQwclklPw4fFjczUWorKDJkSTVGRFwqN0NhfSVeJl8rOEw9N14/NGJ5Sk hbSVxNTk9KW1xdXl9VZmdoaWprbG1ub2N0dXZ3eHl6e3x9fn9xEAAgIBAgQEAwQFBgcHBgU1AQAC EQMhMRIEQVFhcSITBTKBkRShsUIjwVLR8DMkYuFygpJDUxVjczTxJQYWorKDByY1wtJEk1SjF2RF VTZ0ZeLys4TD03Xj80aUpIW0lcTU5PSltcXV5fVWZnaGlqa2xtbm9ic3R1dnd4eXp7fH/9oADAMB AAIRAxEAPwCv0T+n4/8AxrP+qavW15J0U/r+P/xrP+qavWg8eKElsWSHZfXWYe4A+ZUMjIFTJBE/ Fc1kXbg63mJP+amk0uesGqdc19Sup2ZrLmWGQxwLR4B35v8A0V0qKlJJJIqUkkkkpSSSSSlJJJJK UkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSS SSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJ KUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpS SSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJ JKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkp SSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJJJKUkkkkpSSSSSlJJ JJKUkkkkpSSSSSn/0J9G6oKn04zKKXOdYA6x7d1kOP8Ag/3Hs/MXY/sOl/0hYfCT/wCQavnZJArQ /S1HTXVN21+weYa7/vqzcroeQ+Q3XcYOn/mbF89pIaJfpboXRK+k1uDQPUsILyONPotZ/JatRfKq SSX6qSXyqkip+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJ KfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp +qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6 qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqp JfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl 8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXy qkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKq SSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJ KfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp +qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn6 qSXyqkkp+qkl8qpJKfqpJfKqSSn6qSXyqkkp+qkl8qpJKfqpJfKqSSn/2Q== - ------=_NextPart_000_008B_01BE9258.D5499820-- ------------------------------ Date: Thu, 29 Apr 1999 19:52:37 -0400 From: Frederic Breitwieser Subject: Re: Fuel injector choice? > My intake (I tig'd it, but it gives you the idea): > http://www.xephic.dynip.com/dodge/dodge.html I forgot to say, click "engine", then "383cid" then "EFI Intake" on the flip down menus on the left frame. um, ooops. ------------------------------ Date: Thu, 29 Apr 1999 19:56:37 EDT From: AL8001@xxx.com Subject: Re: Fuel injection plugs In a message dated 99-04-29 12:48:18 EDT, Steve.Ravet@xxx.com writes: < lots of stuff cut out > >The spark engine burns it's fuel much faster than the diesel engine. it burns while the size of the combustion chamber is not >changing size that much (right around TDC). That's where the work comes from. > >The diesel engine injects and burns fuel during the whole power stroke. >While the fuel is burning and trying to raise pressure, the piston is >moving down and releasing pressure. > >--steve > > So, would it be safe to deduce that these specific differences are the reason a diesel has much higher torque output than a similar sized gas engine? Harold ------------------------------ Date: Thu, 29 Apr 1999 21:46:40 -0400 From: "Bruce Plecan" Subject: Re: Need Fuel Injector Data Couple things come to mind. GM 1987 Sunbird 2.0L 4 cylinder Turbo might be close, they are P+H. www.lindertech.com that's off the top of my head but they are in gasoline Alley Indianapolis, IN. Then RC Eng in SoCal.. How much info do you have about that ecms prom calibrations?. If your point man is gone, you might need to reevaluate your posistion. Bruce > A friend of mine and I are working on an unusual project. We are adapting a > '93 Saturn ECM and two DIS modules to run a Continental O-200 aircraft > engine. The engine is 200 C.I. (3.3 L) 4 cylinder dual plug and should make > about 120 HP at about 2800 RPM. > > Can anyone supply us with the information or give us an idea of where we can > find a chart with the injector data? ------------------------------ End of DIY_EFI Digest V4 #250 ***************************** 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".