DIY_EFI Digest Tuesday, 26 August 1997 Volume 02 : Number 289 In this issue: Re: Coil-on-Plug Systems Re: Coil-on-Plug Systems Injection timing Injection timing Re: Injector control question P4ECM-SWITCHING Re: Injector Control Re: EFI & furthermore Re: Coil-on-Plug Systems Header parts... O2 sensor buffering/interfacing Re: Header parts... Re: For REALLY good injection, check this out : Re: Anti-turbo lag systems Re: For REALLY good injection, check this out Converting CFM to Lbs/min Re: P4ECM-SWITCHING Re: Coil-on-Plug Systems Re: P4ECM-SWITCHING WOOPS! Re: Coil-on-Plug Systems Re: Header parts... Re: O2 sensor buffering/interfacing Re: Injector control question Re: Converting CFM to Lbs/min Re: Coil-on-Plug Systems Re: Header parts... Re: Injector control question Re: Header parts... Audi A6 TDi 140 Diesel! See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: DemonTSi@xxx.com Date: Mon, 25 Aug 1997 04:59:40 -0400 (EDT) Subject: Re: Coil-on-Plug Systems In a message dated 97-08-25 04:11:27 EDT, you write: << These seem like they could be fired with the current version of EFI332 hardware. Since I am building a 4 cylinder motor, it seems like it should take no more individual driver capacity than a 4-pack wasted-spark coil for a V8. Anybody have further information or ideas? >> You might also want to look into the system that Nissan uses. Most of their engines use a single coil per cylinder ign setup...In the US, I think they've had it on some V6s as far back as 89. ------------------------------ From: txhartma@xxx.com (Terry Hartman) Date: Mon, 25 Aug 1997 06:42:36 -0500 Subject: Re: Coil-on-Plug Systems > From: Gary Ohst > > Subject: Coil-on-Plug Systems > > > 5) All I cound find on what Delco is up to. Just a few sentences at > the end of a general racing technology page. To my knowledge, GM has no ^^^^^^^^^^^^^^^^^^^^^^^^^^^ > production coil-on-plug units like Ford. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > http://www.delco.com/autosmart/96_spring/track.html Get up to date by checking out the new LS1 in the '97+ Corvette and the '98 F-body (Firebird & Camaro) cars.... T. ------------------------------ From: dusher@xxx.com Date: Mon, 25 Aug 1997 09:08:42 BST Subject: Injection timing Can anyone help me with the timing for fuel pulse and duration at differant engine speeds,I know that it depends on load and the rest of it. But just an idea of general timing for an 'average car' would be good!. And what would be nice is to get the whole timing picture, ie: intake open fuel pulse intake close etc etc. Basicaly the _WHOLE_ EFI theory!!!!..... ,Ok thanks bye......Dave G6ZKC any graphs etc would also be good! via dave@xxx.uk - -- ------------------------------ From: dusher@xxx.com Date: Sun, 24 Aug 1997 14:24:16 BST Subject: Injection timing Can anyone help me with the timing for fuel pulse and duration at differant engine speeds,I know that it depends on load and the rest of it. But just an idea of general timing for an 'average car' would be good!. And what would be nice is to get the whole timing picture, ie: intake open fuel pulse intake close etc etc. Basicaly the _WHOLE_ EFI theory!!!!..... ,Ok thanks bye......Dave G6ZKC any graphs etc would also be good! via dave@xxx.uk - -- ------------------------------ From: Tom Cloud Date: Mon, 25 Aug 1997 07:55:21 -0500 Subject: Re: Injector control question >> >> In examining my Holley ProJection (model 502 analog) I find >> >> that the pulse width to the injectors is a constant (approximate) >> >> [ snip ] >> >> >> NEXT ... >> >> >> >> Some time back (few weeks ago) there was a question >> >> about building a meter to monitor the PW of injectors >> >> "why does one want to know the PW when it's the >> duty cycle that's impotent (regardless of whether >> one uses fixed PRR/var. PW or fixed PW/var. PRR) ?? >> Am I incorrect about that ?? I recognize that there's going >> to be errors in fuel delivery calcs at the opening and closing >> of the injector, so short pulses would deliver less fuel/time >> than long pulses and this would imply that a simple duty >> cycle measurement would have some inherent errors, but I'd >> think they'd be minimal. >> >> IOW, seems that duty cycle is what you want to measure, not PW ???? >Why would you want to know the duty cycle? Other than determining if you >break 85% and rick holding the injector open... If you have a sequential >port efi, wouldn't you align the injectors in phase with the intake >event,, so frequency would vary with rpm, then adjust pulse width >according to volumetric efficiency at that point (determined by MAP or >throtle position). That is what I am designing around with my 68HC11 >project. They duty cycle is all over the map from ~1.5% to ~85%, but the >pulse width is from 1.5ms to 18 ms. Maybe I am overlooking something? - one, I'm using TBI (or CPI) not TPI, so the relation of the injector firing to my actual valve opening is not important (is it ??? ). - second, the duty cycle is the amount of fuel you're delivering -- depending on the pressure differential across the injector, the injector "rise" and "fall" (open and close) times, etc. I'm asking because I don't know ..... still seems to me that knowing the duty cycle is more important (and much easier to measure) than actual pulse width time. If you're worried about *when* the pulse is triggered relative to the valve opening (I assume we're talking a certain no. of degrees from TDC), then that's another kettle a'fish again -- isn't it? If you know the duty cycle and the rpm you can deduce the pulse width -- but not with great accuracy (depends on the accuracy of your duty cycle and rpm measurement). Tom Cloud Ever stop to think .... and forget to start again ?? ------------------------------ From: Justin Albury Date: Mon, 25 Aug 1997 23:09:22 +1000 Subject: P4ECM-SWITCHING HI ALL A FEW WEEKS AGO I STARTED OF WITH THE TOPIC OF SWITCHING EPROM CHIPS AND HAD A FEW REPLYS WHICH ENABLED ME TO CHANGE MY DESIGN FOR THE BETTER. NOW FOR THOSE OF YOU WHO ARE RUNNING THE DELCO P4 (IM USING THE 808) THE SIMPLEST WAY AND MOST EFFECTIVE IS : OH YEH THE ORIGNAL EPROM IS A 27C128, THIS IS REPLACED WITH A 27C256 1 - PROGRAM THE EPROM CHIP, THE FIRST FILE LAYS AT 00000 - 03FFF AND THE SECOND AT 04000 - 07FFF 2 - MOUNT IT IN THE MEMCAL (IF YOU MOUNT A SOCKET FLUSH THEN POP THE NEW EPROM IN YOU CAN STILL GET THE MEMCAL LID BACK ON) 3 - STICK IT BACK INTO THE ECM (THE MEMCAL THAT IS) 4 - PICK UP A 12+ POWER FEED FROM THE IGNITION, RUN IT THROUGH A SWITCH MOUNTED ON THE DASH/CONSOLE, THEN TO PIN C9 AT THE ECM 5 - SIMPLE .... WHEN 12+ IS APPLYED THE EPROM AT PIN 27 (A14) IS SWITCHED HIGH BY THE ECM AND WHEN POWER IS TAKEN AWAY THE ECM SWITCHED THE EPROM LOW. 6 - I LIKE THE K.I.S.S. METHOD! GM HOLDEN HAVE BEEN USING THIS METHOD SINCE 1991 ON LPG SYSTEMS SO WHY NOT USE IT IN ANY WAY WE CAN. OH YEH ITS BEST TO KEEP THE SAME BASE PROGRAM AND ONLY CHANGE THE DATA BETWEEN EACH FILE.... ALL THE BEST! Justin jalbury@xxx.au ------------------------------ From: Tom Cloud Date: Mon, 25 Aug 1997 08:12:38 -0500 Subject: Re: Injector Control >Hi! >I was study for some time the injector signal , and , in my opinion , >the pulse width can't be constant . The PW increase or decrease ( aprox. >between 1% to 85% ) according with throttle position and / or MAP sensor >( or airflow sensor ). >If you have right and the PW it's constant , how you increase the RPM >when you press the throttle ? >I'm using this type of modulation ( PW ) on my project and 'till now >it's >OK . >Alex Alex if you have a 1 mS pulse width -- held constant. - with a period of 100 mS, you would have a duty cycle of 1% - 10 mS period would give 10% duty cycle - 1 mS period would give 100% duty cycle So, you can keep the width constant and vary the period to change the duty cycle (this works on throttle body injection systems -- wouldn't be feasible for port injection) If you have port injection, you'd need PW (pulse width) modulation, since the injectors are timed with the rpm of the engine (in the scenario above, the timing is totally unrelated to the engine rpm, but here, it's tied directly to it). But, with either scheme, isn't it the injector open time in relation to the injector firing rate (PW/PRR) that determines the amount of fuel delivered ??? And this is duty cycle, is it not? And duty cycle is easily measured (it's called a "dwell meter" and we all have one of those -- or at least I do 8^) Tom Cloud Ever stop to think .... and forget to start again ?? ------------------------------ From: "Robert Harris" Date: Mon, 25 Aug 1997 07:11:27 -0700 Subject: Re: EFI & furthermore Exact Meaning = Propane (C3H8) is example Fairly Exact = LPG (Liquified Petroleum Gas - contains 50 to 90 % propane, but still well defined random blend of certain gas's) - often interchanged with propane Faily Exact=Intercooler (properly an air charge cooling device between stages), now in general usage includes aftercoolers(devices that do air charge cooler after the last external stage of cooling) "When some one gets something for nothing - some one else gets nothing for something " If the first ingredient ain't Habanero, then the rest don't matter. Robert Harris > > Oh, not to beat it to death, and to be perfectly clear, you state "Words > have > > meanings, - chemical, physical, electrical etc terms have fairly > > exact meanings." > > I already know that words have meanings, since I use them on a more or > less non-arbitrary basis, but what does "fairly exact" mean? I > understand that the english language also has context, and "fairly" is a > contradiction in context with "exact". Not to be so bold as to > contradict you outright, but I understand, and believe to be true, that > mathematics was "invented" as the "language" of science, due to its > exacting precision and unabiguity in fairly describing the various > scientific doctrines. > ------------------------------ From: "Corey L. Cole" Date: Mon, 25 Aug 1997 08:26:48 -0700 Subject: Re: Coil-on-Plug Systems Terry Hartman wrote: > > > From: Gary Ohst > > > > Subject: Coil-on-Plug Systems > > > > > > > 5) All I cound find on what Delco is up to. Just a few sentences at > > the end of a general racing technology page. To my knowledge, GM has no > ^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > production coil-on-plug units like Ford. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > http://www.delco.com/autosmart/96_spring/track.html > > Get up to date by checking out the new LS1 in the '97+ Corvette and the '98 > F-body (Firebird & Camaro) cars.... > > T. No need to spend over $20K to get a coil on plug GM car...look no further than the Quad 4. - -- ============================================================================== Corey L. Cole | I was standing on the side of the road, M/S 19-HH | rain falling on my shoe. E-mail: corey.l.cole@xxx.com | I was heading for the east coast, Phone: 206-662-3596 | Lord knows I've paid some dues. | Tangled up in blue. ============================================================================== ------------------------------ From: "John C. Lagerquist" Date: Mon, 25 Aug 97 10:26:32 Subject: Header parts... I am looking for some sources for header parts i.e. U-bends, J-bends and particularly 2 into 1 collectors. Any suggestions? John C. Lagerquist (vision_a@xxx.net) Staff Engineer Control Vision, Inc. #include ------------------------------ From: "John C. Lagerquist" Date: Mon, 25 Aug 97 10:38:08 Subject: O2 sensor buffering/interfacing I am looking for a circuit example to buffer an O2 sensor. I am unable to obtain the LM9904, and would like an equivalent circuit. John C. Lagerquist (vision_a@xxx.net) Staff Engineer Control Vision, Inc. #include ------------------------------ From: "Jason G." Date: Mon, 25 Aug 1997 11:05:25 -0700 (PDT) Subject: Re: Header parts... Look at 68 -72 Datsun 510s and trucks and 85 (I think )200sx for 2 into 1 parts Jason G. At 10:26 AM 8/25/97, you wrote: >I am looking for some sources for header parts i.e. U-bends, J-bends and particularly 2 into 1 >collectors. Any suggestions? > > >John C. Lagerquist (vision_a@xxx.net) >Staff Engineer >Control Vision, Inc. > >#include > > > > > > <<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>> http://rogue.northwest.com/~verde >>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<< ------------------------------ From: jb24@xxx.com Date: Mon, 25 Aug 1997 16:08:40 -0400 Subject: Re: For REALLY good injection, check this out >>One element that nobody seems to pay much attention to is the fact that roughly 80% of the air component is nitrogen, and does absolutely bupkiss, except pollute the crap out of everything. Being a diver, I'm acutely aware of nitrogen saturation of tissue under pressure, and the effect that compression has on the partial pressures of the various gasses. I suppose the so called "oxygenation" of fuel has some merit, but it's still a concept trying to formulate fuel to fit both carbed, and injected engines. That's just plain stupid. If the gas companies want to get on the boat, why not formulate a fuel specifically for injected engines, (like diesel is), and make a serious attempt to saturate the fuel with oxygen, so that the intake air stream is reduced. Hell, they could even get into agriculture, and use the oxygen given off by plants as the source by tapping the enriched air of the massive acres of greenhouses popping up everywhere. I have no idea what sort of oxygen absorption a particular liquid hydro-carbon has, (pressure dependant, among other things), but getting even a small amount of the nitrogen out of the process in favour of oxygen has big leverage on combustion and power efficiency, as does recovering lost heat, and moving heat out of the intake charge.<< Only problem is fuel costs - and the density of the oxygenated supplements (both generally higher). John Bucknell ------------------------------ From: ptimmerm@xxx.GOV Date: Wed, 13 Aug 1997 16:02:22 -0700 Subject: : Re: Anti-turbo lag systems I think the idea of dumping the hydrocarbons down the exhaust system was used earlier by Audi, although they were in hot compietition with Peugout at the time. The Groupe B quattros and the Pikes Peak car had a fuel injector that dumps fuel during shifts. Not a good idea if you have a cat attached to your exhaust, but effective. I was suprised to hear someone say compressed air. That would not last very long! Propane would be OK, but why carry two fuels? ------------------------------ From: jb24@xxx.com Date: Mon, 25 Aug 1997 16:05:51 -0400 Subject: Re: For REALLY good injection, check this out >>Orbital engine from Australia has been experimenting with this for several years for 2-stroke engines. As I understand it the proper amount of fuel is blown into the combustion chamber with ~100 psi air. A small belt driven compressor supplies the air. The idea is to get good atomization and allow injection after the exhaust port has been covered (preventing raw fuel from going out the exhaust). They have licensed the technology to GM, Ford, Toyota and others. So far nothing meeting NOx has been a problem so no marketable engine has come out. << The only problem with Orbital's engine (and all other automotive two-strokes so far) is while raw fuel doesn't escape down the exhaust port, unburned oxygen does. So the O2 sensor sees a lean mixture (not a big problem in itself, what mapping is all about) but so to does the catalyst. Catalysts are designed for stoic, so the catalyst-out emissions aren't as good as four-strokes, even though engine-out emissions are much lower. If the catalyst industry figures out how to make lean-burn catalysts, many many two-strokes will be on the road. John Bucknell ------------------------------ From: Simon Quested Date: Tue, 26 Aug 1997 09:53:08 +1200 Subject: Converting CFM to Lbs/min Hi All Can anyone tell me the formula for converting cfm to lbs'min @ 200ft and 68 F (20 C) Cheers Simon +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Simon Quested (E-mail questeds@xxx.nz) Computer Technician, Silicon Graphics & Windows NT Support Centre for Computing and Biometrics LINCOLN UNIVERSITY OF NEW ZEALAND Phone (64)(03) 3252811 Ext. 8087 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ http://www.lincoln.ac.nz/ccb/techs/simon/default.htm +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ When the chips are down, the cow is empty. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------ From: lambs@xxx.au (Stephen Lamb) Date: Tue, 26 Aug 1997 10:44:59 +1000 Subject: Re: P4ECM-SWITCHING >A FEW WEEKS AGO I STARTED OF WITH THE TOPIC OF SWITCHING EPROM CHIPS AND >HAD A FEW REPLYS WHICH ENABLED ME TO CHANGE MY DESIGN FOR THE BETTER. > >NOW FOR THOSE OF YOU WHO ARE RUNNING THE DELCO P4 (IM USING THE 808) THE >SIMPLEST WAY AND MOST EFFECTIVE IS : Certainly appear to have reason to be pleased with yourself, but theres no need to shout.......... As an aside, theres an interesting series of articles in recent Silicon Chip issues giving some details about the DELCO ECM's used in locally made Commodes. There's some guy (possibly in South Oz) that's written a comprehensive software package for re-programming the beasts for performance apps. I'll post his name and contact number if anyone's interested. Cheers Stephen Lamb Dept. of Defence DSTO, AMRL 506 Lorimer Street Fishermans Bend VIC 3207 Australia Tel: +61 3 9626 7525 Fax: +61 3 9626 7089 IZCC #180 ------------------------------ From: Johnny Date: Mon, 25 Aug 1997 18:45:04 -0700 Subject: Re: Coil-on-Plug Systems Terry Hartman wrote: > Get up to date by checking out the new LS1 in the '97+ Corvette and the '98 > F-body (Firebird & Camaro) cars.... Speaking of '98 F-body, do you know if they are offering a 90 degree V6 with aluminum heads? I mean the Vortec, or 4.3L or whatever you want to call it, but with a new set of heads and sequential injection like it's big brother? - -j- ------------------------------ From: Jennifer Rose Date: Mon, 25 Aug 1997 18:52:35 -0700 Subject: Re: P4ECM-SWITCHING At 10:44 AM 8/26/97 +1000, you wrote: >>A FEW WEEKS AGO I STARTED OF WITH THE TOPIC OF SWITCHING EPROM CHIPS AND >>HAD A FEW REPLYS WHICH ENABLED ME TO CHANGE MY DESIGN FOR THE BETTER. >> >>NOW FOR THOSE OF YOU WHO ARE RUNNING THE DELCO P4 (IM USING THE 808) THE >>SIMPLEST WAY AND MOST EFFECTIVE IS : > >Certainly appear to have reason to be pleased with yourself, but theres no >need to shout.......... > >As an aside, theres an interesting series of articles in recent Silicon >Chip issues giving some details about the DELCO ECM's used in locally made >Commodes. There's some guy (possibly in South Oz) that's written a >comprehensive software package for re-programming the beasts for >performance apps. I'll post his name and contact number if anyone's >interested. > >Cheers > >Stephen Lamb >Dept. of Defence DSTO, AMRL >506 Lorimer Street >Fishermans Bend VIC 3207 Australia >Tel: +61 3 9626 7525 >Fax: +61 3 9626 7089 > >IZCC #180 > > > Yes please post info- any help in learning how these thing work is always helpful Vance ------------------------------ From: Justin Albury Date: Tue, 26 Aug 1997 12:12:14 +1000 Subject: WOOPS! Sorry about my message on switching eproms typed all in uppercase iv been running in hi res playin around and got to reading/sending mail and couldnt see what i was typing.....oh well sorry all Justin ------------------------------ From: muwtj1@xxx.edu (Bill Jenkins) Date: Mon, 25 Aug 1997 19:56:57 -0700 (PDT) Subject: Re: Coil-on-Plug Systems >Terry Hartman wrote: > >> Get up to date by checking out the new LS1 in the '97+ Corvette and the '98 >> F-body (Firebird & Camaro) cars.... > >Speaking of '98 F-body, do you know if they are offering a 90 degree V6 >with aluminum heads? I mean the Vortec, or 4.3L or whatever you want to >call it, but with a new set of heads and sequential injection like it's >big brother? > I've read that when the 1999 Chevrolet full-size pickup is introduced, it will have a cast-iron version of the LS1; simultaneously the 90-degree "Vortec" V-6 will be re-engineered with LS1-like components, but it will still be cast-iron head. Bill Jenkins muwtj1@xxx.edu http://www.wiu.edu/users/muwtj1 The Chevrolet Beretta Home Page ------------------------------ From: Sandy Date: Mon, 25 Aug 1997 20:25:39 -0700 Subject: Re: Header parts... Their is a place called 'HEADERS BY ED' that sells everything you could ever need, from flanges, to a bunch of bends, to complete kits. Seems to be an expert at header designs as well. I don't have the catalog, as I lent it to my cousin, and have not seen it for a couple of months, but should be in some older hot rods or kit car mags. Sandy At 10:26 AM 8/25/97, you wrote: >I am looking for some sources for header parts i.e. U-bends, J-bends and particularly 2 into 1 >collectors. Any suggestions? > > >John C. Lagerquist (vision_a@xxx.net) >Staff Engineer >Control Vision, Inc. > >#include > > > > > ------------------------------ From: Sandy Date: Mon, 25 Aug 1997 20:28:19 -0700 Subject: Re: O2 sensor buffering/interfacing You can try the circuit that I made for the I/O board for the EFI332 project. It is untested with anything as yet (so i think) but it should work pretty well. The op-amp is suited for automotive use, and the sample circuit that is out on the EFI332 FTP site should do the trick. The gain is set for 4.9 so a typical o2 sensor will give a range that is good for an A/D converter that has a 5 volt reference. Hope that helps, ps, let me know if it works! Sandy At 10:38 AM 8/25/97, you wrote: >I am looking for a circuit example to buffer an O2 sensor. I am unable to obtain the LM9904, and >would like an equivalent circuit. > > > >John C. Lagerquist (vision_a@xxx.net) >Staff Engineer >Control Vision, Inc. > >#include > > > > > ------------------------------ From: MaxBoost@xxx.com Date: Mon, 25 Aug 1997 23:42:40 -0400 (EDT) Subject: Re: Injector control question > I'm asking because I don't know ..... still seems to me that > knowing the duty cycle is more important (and much easier to > measure) than actual pulse width time. If you're worried about > *when* the pulse is triggered relative to the valve opening > (I assume we're talking a certain no. of degrees from TDC), > then that's another kettle a'fish again -- isn't it? I don't know of any current production engine that uses anything other than closed valve injection. That means you fire the injector onto the backside of the warm intake valve and let the fuel start to evaporate before the valve opens. Every thing I've ever read on open valve injection says that you cannot get good enough vaporization from the injector alone and you will wash the cylinder walls down and 'make oil'. IF you could aim the injector to hit the very hot exhaust valve, then you would have something, but getting an injector to hit the exhaust valve on a current engine would be quite a trick. Of course the above doesn't apply to the new direct injection engines developed by the japanese in the last year or so. Also this is in consideration of lower engine rpms, at high speed the cycles occur so quickly that the injector is open most of the time anyway. FWIW the Nissan CONSULT diagnostic computer gives a direct readout in pulse width. Many of their ecu's also have a pin that is dedicated to read this function only. Max ------------------------------ From: A70Duster@xxx.com Date: Tue, 26 Aug 1997 01:24:28 -0400 (EDT) Subject: Re: Converting CFM to Lbs/min What is the medium, air??? See ya, Mike ------------------------------ From: Johnny Date: Mon, 25 Aug 1997 22:41:36 -0700 Subject: Re: Coil-on-Plug Systems Bill Jenkins wrote: > > >Terry Hartman wrote: > > > >> Get up to date by checking out the new LS1 in the '97+ Corvette and the '98 > >> F-body (Firebird & Camaro) cars.... > > > >Speaking of '98 F-body, do you know if they are offering a 90 degree V6 > >with aluminum heads? I mean the Vortec, or 4.3L or whatever you want to > >call it, but with a new set of heads and sequential injection like it's > >big brother? > > > > I've read that when the 1999 Chevrolet full-size pickup is introduced, it > will have a cast-iron version of the LS1; simultaneously the 90-degree > "Vortec" V-6 will be re-engineered with LS1-like components, but it will > still be cast-iron head. To let the cat out of the bag a bit more, I am desperately looking for a source for aluminum heads for Vortec V6. Chev used to make 3 different sets. 2 that were mild and 1 that was crazy with huge ports and canted valves. They have discontinued all but the full race ones which are too large of volumes for what I need and don't accept the standard manifolds. I had heard that Edelbrock had done some preliminary design work for a "Performer RPM" series head for this engine, but had never completed it. I called and talked to Vic Jr. last week and he confirmed that one of the engineers had done some drawings but "we are not working on it at the present time". I begged and pleaded, and even brought up the fact that tooling would be a cinch because of the likeness to the SBC head in ports, valve placement, chamber, stud placement, accessory holes, etc., but I couldn't get him to budge. They want to sell 400-500 sets a year, and he doesn't think the market is there, even though they have had other calls like mine asking about it. Does anyone know of another source for aluminum heads for this engine? The desire for aluminum is strictly from a weight standpoint. I need to lose the 40-50 pound difference that they make. I had heard that the new F-body was going to use the 4.3 revamped with aluminum heads, but I have not been able to get the various dealers to confirm or deny this yet. What does the 500 or so people on diy_efi know about it? And, does anyone have some of the earlier set from chev laying around that they want to sell? I know this ain't the chev list, but it's for an efi conversion setup. - -j- ------------------------------ From: Johnny Date: Mon, 25 Aug 1997 22:49:23 -0700 Subject: Re: Header parts... Sandy wrote: > > Their is a place called 'HEADERS BY ED' that sells everything you could > ever need, from flanges, to a bunch of bends, to complete kits. Seems to be > an expert at header designs as well. I don't have the catalog, as I lent it > to my cousin, and have not seen it for a couple of months, but should be in > some older hot rods or kit car mags. > Header Parts Target Audience: Consumer Publishing Co: Headers by Ed, Inc. Tel: (612) 729-2802 Staff: Publisher - Eddy Henneman Product Line: Complete line of header & custom exhaust parts for the individual or professional fabricator. Largest selection of Header Parts in U.S. covering over 100 different U.S. made 4, 6, V-6, & V-8 engines. Catalog offers information on header & exhaust systemesign plus many essential performance & construction tips. Frequency Of Issue: Annually Subscription: Annual Sub.-individual $3.75, $3.75/copy - -j- ------------------------------ From: Johnny Date: Mon, 25 Aug 1997 22:56:51 -0700 Subject: Re: Injector control question MaxBoost@xxx.com wrote: > > > I'm asking because I don't know ..... still seems to me that > > knowing the duty cycle is more important (and much easier to > > measure) than actual pulse width time. If you're worried about > > *when* the pulse is triggered relative to the valve opening > > (I assume we're talking a certain no. of degrees from TDC), > > then that's another kettle a'fish again -- isn't it? > > I don't know of any current production engine that uses anything other than > closed valve injection. That means you fire the injector onto the backside > of the warm intake valve and let the fuel start to evaporate before the valve > opens. Every thing I've ever read on open valve injection says that you > cannot get good enough vaporization from the injector alone and you will wash > the cylinder walls down and 'make oil'. IF you could aim the injector to hit > the very hot exhaust valve, then you would have something, but getting an > injector to hit the exhaust valve on a current engine would be quite a trick. Does this mean that all of those first years of GM TPI are sequential injection? - -j- ------------------------------ From: eric schumacher Date: Tue, 26 Aug 1997 00:23:52 -0700 Subject: Re: Header parts... JC Whitney sells mandrel bends for rolling your own. Lotsa Luck Eric 85 GTI with VR6 power ------------------------------ From: dusher@xxx.com Date: Tue, 26 Aug 1997 09:06:11 BST Subject: Audi A6 TDi 140 Diesel! Anyone any idea how read in real-time the params of an Audi A6 Tdi, ie like Rinda's Diacom?? for Chrysler etc.......Any ideas OK bye Dave Usher.... - -- ------------------------------ End of DIY_EFI Digest V2 #289 ***************************** 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".