DIY_EFI Digest Wednesday, 27 March 1996 Volume 01 : Number 088 In this issue: Re: DIY_EFI Digest V1 #87 Re: 4.3 multi-port fuel injection injector sizing TEC Returned Maial crank/cam + ignition/fuel 68332 timing relationships unusbscribe Re: crank/cam + ignition/fuel 68332 timing relationships Re: TEC lambda sensor Re: 4.3 multi-port fuel injection [none] Honda "leanburn" Sensors Re: Injectors Multi Spark Ignition... Re: Multi Spark Ignition... Re: Multi Spark Ignition... Re: 4.3 multi-port fuel injection Re: LPG + low octane pump gas LPG injection Re: LPG injection injector pulse width Re: Multi Spark Ignition... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: talltom Date: Tue, 26 Mar 1996 04:13:15 -0800 Subject: Re: DIY_EFI Digest V1 #87 >------------------------------ > >From: Charles Morgan >Date: Mon, 25 Mar 1996 18:51:05 -0800 (PST) >Subject: Re: 4.3 multi-port fuel injection system > >On 3/25/96 -0600, Ryan Harrell wrote: >>I was wondering if anybody knows if Chevrolet (or any aftermarket vendor) has >>a multi-port fuel injection system available for a 4.3L V6. I believe there >>is one, but I have no information on one. If so, does anybody know of a >>manufacturer who makes computers for these engines (Everybody seems to be >>obsessed with V8 engines)... > >The turbocharged 4.3L V6 that Chevy used in the Typhoon/Cyclone models is >true multi-port, but getting one of these would be darn near impossible >(I've tried). The 4.3L Vortec V6 introduced by Chevy in 1992 is called >"Central Multi-Port Fuel Injection" although it uses a single injector with >poppet valves at each intake port. It's performance, however, is very >adequate. Turbo City (714-997-1196) sells a multi-port kit for non-Vortec >4.3L V6s; I beleive they use a GM computer. > >Charlie Morgan > >------------------------------ > >From: Jim Steck <72614.557@xxx.com> >Date: 25 Mar 96 23:27:29 EST >Subject: 4.3 multi-port fuel injection > >>I was wondering if anybody knows if Chevrolet (or any aftermarket vendor) >>has a multi-port fuel injection system available for a 4.3L V6. > >Haltech's competition is : > >Electromotive >14004-J Willard Drive >Chantilly, VA 22024 > >1-800-843-3889 > >They also use GM sensors. I've built three engines with their TEC systems . . . >including two 300 horsepower 2.0 liter turbocharged Alfa Romeos. Their system >has been very reliable (no failures in 100,000 cumulative miles) and is very >flexible. Prices are similar to Haltech. > >- -Jim Steck >AutoComponenti And for those "obsessed" with v8's I believe the 96 Chev 454 also uses whatever G.M. calls it's version of Bosch's constant injection system. Haven't seen one, but have read that it operates on the same barn door blowing in the breeze configuration and poppet valves in the ports. ------------------------------ From: Fred Miranda Date: Tue, 26 Mar 1996 05:25:07 GMT Subject: Re: 4.3 multi-port fuel injection I've built three engines with their TEC systems . . . Their system >has been very reliable (no failures in 100,000 cumulative miles) and is very >flexible. Prices are similar to Haltech. > >-Jim Steck >AutoComponenti you have been lucky. both the TECs I have have failed. the first (a TEC1) died after 8 months in my autocross Spitfire. the second (TEC2) developed an intermitant problem after about 2 years and 30kmiles in the 323. Fred ------------------------------ From: Jim Steck <72614.557@xxx.com> Date: 26 Mar 96 08:41:25 EST Subject: injector sizing Here are some more injectors at the low end of the flow range. This was taken from a Bosch sizing chart (in German) . . . now about 5 years old. There certainly will be more choices by now. Even the new motorcyles are using EFI. Manuf. Part # Flow @xxx.5 bar ================================================ Bosch 423700 21.4 (Porsche) Bosch 423710 16.7 (Alfa Romeo) Bosch 423719 13.6 (Renault) Bosch 423731 17.0 (BMW) Bosch 423732 16.7 (BMW) Bosch 793725 24.2 (Audi) Bosch 793730 24.2 (Audi) Bosch 793733 24.2 (Audi) - -Jim Steck AutoComponenti ------------------------------ From: Jim Steck <72614.557@xxx.com> Date: 26 Mar 96 10:02:14 EST Subject: TEC >>I've built three engines with their TEC systems . . . >>Their system has been very reliable (no failures in 100,000 cumulative miles) > and is very flexible. Prices are similar to Haltech. >> >>-Jim Steck >>AutoComponenti >you have been lucky. >both the TECs I have have failed. the first (a TEC1) died after 8 months in my >autocross Spitfire. the second (TEC2) developed an intermitant problem >after about 2 years and 30kmiles in the 323. I hope it continues. The oldest system was installed 8 years ago and has seen 60,000 miles. The only problem I've ever had was a magnetic pickup I damaged by mounting it a little too close to the trigger wheel (the crank moved around more than I expected). That created an intermittant problem that was solved by replacing the pickup. - -Jim ------------------------------ From: Stephen Callender Date: Tue, 26 Mar 1996 11:32:03 -0500 Subject: Returned Maial If you were trying to contact the following, please note the correct address. mrdown@xxx. Downs [Mike] Either the user name or host name was incorrect. Also the domain most.magec.com has been changed to most.fw.hac.com because of the purchase of Magnavox by Hughes Aircraft. The domain magec.com will disappear after March 26, 1996. Message headers follow: ----- Transcript of session follows ----- 554 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05979; Tue, 26 Mar 96 06:18:56 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005955; Tue Mar 26 06:16:36 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05952; Tue, 26 Mar 96 06:16:33 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005921; Tue Mar 26 06:14:17 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05918; Tue, 26 Mar 96 06:14:14 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005896; Tue Mar 26 06:12:59 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05893; Tue, 26 Mar 96 06:12:56 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005852; Tue Mar 26 06:10:22 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05848; Tue, 26 Mar 96 06:10:20 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005821; Tue Mar 26 06:08:52 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05818; Tue, 26 Mar 96 06:08:50 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005784; Tue Mar 26 06:07:16 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05781; Tue, 26 Mar 96 06:07:13 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005732; Tue Mar 26 06:04:40 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05729; Tue, 26 Mar 96 06:04:37 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005644; Tue Mar 26 06:02:04 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05637; Tue, 26 Mar 96 06:02:01 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005585; Tue Mar 26 05:59:21 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05582; Tue, 26 Mar 96 05:59:18 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005541; Tue Mar 26 05:56:45 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05538; Tue, 26 Mar 96 05:56:42 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005509; Tue Mar 26 05:54:21 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05506; Tue, 26 Mar 96 05:54:18 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005463; Tue Mar 26 05:51:51 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05460; Tue, 26 Mar 96 05:51:48 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005431; Tue Mar 26 05:49:33 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05427; Tue, 26 Mar 96 05:49:30 EST Received: from gw1.magec.com(151.168.2.3) by gw1 via smap (V1.3mjr) id smI005408; Tue Mar 26 05:48:14 1996 Received: by most.fw.hac.com (4.1/SMI-4.1) id AA05405; Tue, 26 Mar 96 05:48:12 EST Received: from coulomb.eng.ohio-state.edu(128.146.90.150) by gw1 via smap (V1.3mjr) id smI005381; Tue Mar 26 05:46:13 1996 Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for diy_efi-digest-outgoing id KAA02046; Tue, 26 Mar 1996 10:00:11 GMT Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) for DIY_EFI-Digest-Send@xxx.edu id KAA02040; Tue, 26 Mar 1996 10:00:08 GMT Date: Tue, 26 Mar 1996 10:00:08 GMT Message-Id: <199603261000.KAA02040@xxx.edu> From: DIY_EFI-Digest-Owner@xxx.edu To: DIY_EFI-Digest@xxx.edu Subject: DIY_EFI Digest V1 #87 Sender: owner-diy_efi-digest@xxx.edu Precedence: bulk Reply-To: diy_efi@xxx.edu Stephen Callender Magnavox/Hughes Aircraft Corp 219-429-6557 slcall@xxx.com ------------------------------ From: jfisher@xxx.edu (Jeff Fisher) Date: Tue, 26 Mar 1996 10:49:15 -0600 Subject: crank/cam + ignition/fuel 68332 timing relationships As more and more of my EFI code comes together I'm begining to deal with timing and TPU issues. One that I just can't figure out is the relationship between ignition and fuel injection signals: If you use a crank sensor, you can set up the PSP (position-synchronized pulse generator) TPU function to fire the ignition coils every 90 degrees. No problem. But, I do not see how you can set up this function to fire the fuel injectors from the crank sensor, since they would inject every other complete revolution of the crank. Can you specify angles greater than 360 degrees in PSP? Likewise, if you go with a cam only sensor, you can set up all of the injectors using the PSP function, but the coils would have to fire 2 times for every cam sensor revolution. Is there a way to make the TPU take care of rescheduling the PSP event?? I know you could handle this by having the CPU rewrite the configuration of PSP every time the crank turns over, or every half time the cam turns over. But this seems wrong. It defeats the purpose of the TPU being able to function independantly of the CPU. How would you do it? Thanks, Jeff Fisher ------------------------------ From: Chan Lui Date: Tue, 26 Mar 1996 10:49:30 -0600 (CST) Subject: unusbscribe unusbscribe DIY_EFI cosc19wi@xxx.edu ------------------------------ From: John S Gwynne Date: Tue, 26 Mar 96 12:10:30 -0500 Subject: Re: crank/cam + ignition/fuel 68332 timing relationships - -------- In message , you write: | As more and more of my EFI code comes together I'm begining to deal with | timing and TPU issues. One that I just can't figure out is the | But this seems wrong. It defeats the purpose of the TPU being able to | function independantly of the CPU. | | How would you do it? Use the PMMX, PSP12, and PSP3 TPU functions instead :). (see http://www.cs.ubc.ca/spider/rodb/tpu/tpu.html) This code was made for a 58X wheel, but I would think you could modify it for other sensors if needed. Any reason why your using PSP? John S Gwynne Gwynne.1@xxx.edu _______________________________________________________________________________ T h e O h i o - S t a t e U n i v e r s i t y ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA Telephone: (614) 292-7981 * Fax: (614) 292-7297 - ------------------------------------------------------------------------------- ------------------------------ From: Bruce Bowling Date: Tue, 26 Mar 1996 12:33:48 EST Subject: Re: TEC ~ ~ >>I've built three engines with their TEC systems . . . ~ >>Their system has been very reliable (no failures in 100,000 cumulative miles) ~ > and is very flexible. Prices are similar to Haltech. ~ >> ~ >>-Jim Steck ~ >>AutoComponenti ~ ~ >you have been lucky. ~ >both the TECs I have have failed. the first (a TEC1) died after 8 months in my ~ >autocross Spitfire. the second (TEC2) developed an intermitant problem ~ >after about 2 years and 30kmiles in the 323. ~ And dealing with the personnel at Electromotive ranks right up with removing one's own eye will Channelock pliers (with no pain killers). And they have lawsuits with almost everyone on the planet (with me probbly being the next one on the list). I wonder if they won the $10 million dollar lawsuit against GM (who supposedly stole their ideas)? - - Bruce - -- - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- Bruce A. Bowling Staff Scientist - Instrumentation and Controls The Continuous Electron Beam Accelerator Facility 12000 Jefferson Ave - Newport News, VA 23602 (804) 249-7240 bowling@xxx.gov http://devserve.cebaf.gov/~bowling - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- ------------------------------ From: yudhiar ariestono Date: Wed, 27 Mar 1996 00:43:49 +0700 Subject: lambda sensor Does anybody have any info on adapting a lambda sensor to my toyota engine (7K series engine, 1800 cc)? because the stock ecu did not have one (BTW it is an open loop system and i want to modified it into a close loop system). What type of lambda sensor that matched to my engine, and where i can get it? please help me!!!!!! thank you!!!!!!! ------------------------------ From: Jerry Wills Date: Tue, 26 Mar 96 10:25:14 PST Subject: Re: 4.3 multi-port fuel injection >>>>> "Jim" == Jim Steck <72614.557@xxx.com> writes: Jim> P.S. I want to add water injection to one of the turbos Jim> . . . anyone have any experience with nozzles and solenoids that Jim> will stand up to 50/50 water methanol mix? The old and crude way was a windshield washer setup, and you change the voltage, to change flow. In "Turbocharging" by Hugh McGinas he describes some diff setup and making your own jets for it. Jerry Wills I'll have enough POWER when I can spin the tires at the end of the straight! 89 FJ DERSLYR, DoD#500 KotF(Flag) Mark Donahue, about 917's USC/Information Sciences Institute (USC/ISI) SoCal (310) 822-1511 x 236 ------------------------------ From: "Shaw, Chris" Date: Tue, 26 Mar 1996 14:29:34 -0500 Subject: [none] This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. Contact your mail administrator for information about upgrading your reader to a version that supports MIME. - ------ =_NextPart_000_01BB1B20.A843CE20 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit unsubscribe DIY_EFI shaw_c@xxx.mil - ------ =_NextPart_000_01BB1B20.A843CE20-- ------------------------------ From: Land Shark Date: Tue, 26 Mar 1996 14:51:54 -0700 Subject: Honda "leanburn" Sensors I need to convert the output from a Honda Leanburn Sensor (or a Bosch/NTK UEGO) into a 0-1 volt signal for use by an ECU .. Does anyone have any ideas how to do this .. Does anyone know what type of sensor the Honda one is??? Does it output a Voltage, or is it a constant-voltage "watch the current" one?? Jim Conforti lndshrk@xxx.com ------------------------------ From: "Jim Staff" Date: Tue, 26 Mar 1996 21:46:37 GMT Subject: Re: Injectors > and the pulse widths are down in the 3-6 ms range. The strange thing about > the > injector is that the nozzle is plastic with a large (approximately .080" > diameter) straight orifice, and squirts a collinear stream, not a spray... > > I've considered reworking the orifice to reduce flow/generate a conical > spray. > > Anyone have any suggestions? > > > Cliff Ducharme It would be cool if you could send those schematics to me! (I've got mine done for the PC card) I've had injector problems. I've had problems just getting one, that works. I did however hook up an injector that ran like a carb, it was effected by the engine speed. So it sucked, but anyway it worked ok. It was similar to the one you described, if it's jet black, has a plastic face and fires a stream instead of a conic mist, it's most likely similar to the one I got off an ford, but unfortunatly I had an accident. I had it in the dyno (Which no longer works) I got up to 4.7 hp on my 3.0hp briggs when the improvised carb with port injector exploded. Back to the real topic, there are injectors that are rated for 15.8lbs/hr, that means a 17% duty cycle for a 3.5 hp @xxx. They are Lucas parts # 5208006 If you find a place that sells them tell me I can't find a local place that carries them. (There are only 3 local, and 1 other place I looked at.) Check out bowlings engine page to get information of injector sizing. BTW : Did you ever find Volumetric efficiency curves for these engines?? If not I'll just run the system with dynamic correction (Which is a bitch). ------------------------------ From: "Jim Staff" Date: Tue, 26 Mar 1996 22:41:31 GMT Subject: Multi Spark Ignition... Has anyone here ever played with multi spark ignition? Where instead of firing once the plugs fire 5 to 20 times very quickly. I saw one of them a few days ago on an S10 chevy, it picked up it's power 40% according to the engine dyno!!!! I was thinking about making a DIY version, having flutter on 500ns intervals. I know that it will burn out the ignition coils I have (junk ford coils), I think that would be a cool ignition inprovement for my Briggs, also I was wondering for all you people out there that know what you're doing. Is a 6amp @ 100V transistor enough to switch the power conections to an injector and a standard ignition coil? Thanks, Jim Staff ------------------------------ From: MSargent@xxx. Sargent) Date: Tue, 26 Mar 1996 18:40:40 -0500 Subject: Re: Multi Spark Ignition... That's a Multiple Spark Discharge unit you probably saw. They are commercially available from MSD and available at any speed shop. Since they sell for just over $100, I wouldn't bother building one. I have the marine version in my boat (MSD 6M-2). They don't burn out coils, but replacing your coil with a strong aftermarket coild doesn't hurt. I used the MSD potted high vibration part. As for 40% increase in power ... bull****. Someone is really putting you on. Either that or that S10 must have been just barely running. On my boat I noticed a definate improvement in idle quality, and ease of starting. It also no longer "loads up" when idling, and so I can transition from a slow idle to full throttle without any stumble or hesitation. However, there was no noticable difference in top end speed with the MSD in place. A 40% increase would have resulted in the top end increasing by about 8 MPH (from 45 MPH to 53 MPH), but top end is still around 45. Mike +--------------------------------------------------------------------------+ | Michael F. Sargent | Net: msargent@xxx.com | Phone: 1(613)721-0902 | | Gallium Software Inc.| | FAX: 1(613)721-1278 | +--------------------------------------------------------------------------+ ------------------------------ From: Darrell Norquay Date: Tue, 26 Mar 96 20:14:32 MDT Subject: Re: Multi Spark Ignition... Jim: > Has anyone here ever played with multi spark ignition? Where instead of firing > once the plugs fire 5 to 20 times very quickly. I saw one of them a few days ago Got one in my beater. Works great. Easier starting, better idle, very slight increase in power, but 40%??? No way... > know that it will burn out the ignition coils I have (junk ford coils) It won't burn out the coils, the output is current limited... > for all you people out there that know what you're doing. Is a 6amp @ 100V > transistor enough to switch the power conections to an injector and a > standard ignition coil? Injector, maybe, coil no. You need a high voltage (450V) transistor for the coil driver, because the coil gives high back-emf when you switch it off. Also, you will need some transient protection diodes and possibly a zener or two to protect the transistor. Ed Lansingers article in Circuit Cellar Ink #63 (Oct 95) has a pretty good example of how it should be done. The output transistor is an SK10117. Rating would need to be at least 15A, 450V. (for the cheap solution, use the horizontal output transistor from an old TV) As far as the injector goes, if it is a low resistance (1-2 ohms), you will need to current limit the driver. Resist the urge ;) to just use a resistor to limit current, it will dissipate much too much power and drop the voltage enough so the injector may not open. Use active current limiting. If it is a high resistance (10-15 ohms), just hook one terminal directly to the +12 rail, and the other to the transistor. The transistor will complete the circuit to ground. The injector will have a much lower back_emf than an ignition coil, but the transistor voltage rating will still need to be around 100V, with a current rating at least 50% higher than the injector draws to provide a good safety margin. You will still need some clamping circuitry to protect the transistor from transients. regards dn - -- - ----------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Voice: (403) 243-2220 Calgary, Alberta, Canada Fax: (403) 243-2872 "Absolutum Obsoletum" - If it works, it's obsolete - ----------------------------------------------------------------- ------------------------------ From: William Sarkozy Date: Tue, 26 Mar 1996 22:35:08 -0800 Subject: Re: 4.3 multi-port fuel injection At 10:25 AM 3/26/96 PST, you wrote: >>>>>> "Jim" == Jim Steck <72614.557@xxx.com> writes: > >Jim> P.S. I want to add water injection to one of the turbos >Jim> . . . anyone have any experience with nozzles and solenoids that >Jim> will stand up to 50/50 water methanol mix? > >The old and crude way was a windshield washer setup, and you change >the voltage, to change flow. In "Turbocharging" by Hugh McGinas he >describes some diff setup and making your own jets for it. > > > Jerry Wills >I'll have enough POWER when I can spin the tires at the end of the straight! >89 FJ DERSLYR, DoD#500 KotF(Flag) Mark Donahue, about 917's >USC/Information Sciences Institute (USC/ISI) SoCal (310) 822-1511 x 236 > > > My new boat motor will be using this same technique for detonation control. I'll be running on gasoline under low power, and then iinject M85 or water/methanol solution under boost conditions. My plan is to salvave a roller-vane fuel pump from a port fuel-injected junker. These units usually put about 80-90 PSI. Normally the pump won't run. At about 0" manifold absolute pressure, I'll start the pump, the pressure being regulated by an adjustable orfice (needle valve) in the return line. My DFI system has an additional output to interface to a nitrous oxide system. When a programmed combination of throttle position and boost conditions are met, the output goes high. I'll set it for about 10 PSIG and use this output to open a solenoid valve to the supply jet(s). Here's where I'm lost. My turbo man says to build a plate to sandwich behind the throttle body on my GM TPI system and inject there. I can only imagine the rear cylinders getting most of the juice and melting pistions in the front. The alcohol will not be totally vaporized and will therefore have some inertia, no? It would be relatively easy for me to add individual jets in the runners below the plenum. I think this would be a superior setup. Another concern is the water/methanol mix. I'd like to use M85 (15% gasoline, 85% methanol) and adjust my fuel map to cut back on the gasoline at WOT while I add the juice. Several people have expressed concerns about the different flame propogation rates of methanol versus gasoline. Incidently, the DFI unit also adjusts the ignition lead (plus or minus, programmable) when the nitrous-oxide interface output is high. I suppose using a water/methanol mix really doesn't add fuel, but only acts as a detonation deterrant? If anybody has any ideas on this or has done something similar, I'd like to hear from them. Bill ------------------------------ From: Darrell Norquay Date: Tue, 26 Mar 96 20:37:39 MDT Subject: Re: LPG + low octane pump gas George: > Has any one heard of using low octane pump gas plus LPG or CNG as a possible > octane booster? Yeah, I actually tried this once. I hooked up a standard pressure regulator to a propane tank, (vapor outlet), and plumbed the output of the regulator into the air cleaner. I drilled and tapped a hole into the regulator housing on the back side of the regulator diaphragm, stuck in a fitting, and plumbed a hose into manifold vacuum. The idea was to set the regulator so it was at zero pressure at idle, and as manifold vacuum dropped when the throttle was opened, it would allow the regulator to open up and inject propane into the carb. Sort of a vacuum enrichment valve (similar in principle to an EFI fuel pressure reg)... Results were inconclusive. The problem I was trying to overcome was pinging in the engine no matter how much I cranked back the timing. Turns out it was a completely different problem (it was the transmission - be damned if it didn't sound and act EXACTLY like detonation! The fourth mechanic I took it to finally figured it out) so I abandoned the idea. Later, I converted the engine to LPG fuel anyway, so it got shelved permanently. This is a simple thing to try, anyone who has detonation problems should look into it... regards dn - -- - ----------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Voice: (403) 243-2220 Calgary, Alberta, Canada Fax: (403) 243-2872 "Absolutum Obsoletum" - If it works, it's obsolete - ----------------------------------------------------------------- ------------------------------ From: Mike Klopfer Date: Tue, 26 Mar 1996 22:05:52 -0600 (CST) Subject: LPG injection I was looking at a SAE book on the Natural Gas Vehicle Challenge and several of the entries used Bosch injectors which I'm guessing are standard pintle type injectors used in gasoline vehicles. I took a quick glance at the paper from some Nebraska university and it talked about having two levels of pressure regulation the final one supplying the injectors at 100psi (as I remember). It also seemed that they used two injectors per cylinder to get enough flow. This lead me to wonder what are the reasons for wanting to inject liquid propane instead of propane vapor. From the various threads on the subject I gather that there might be some problem getting the liquid to a vapor at low temperatures. I'd guess that it takes less injection time to inject a given mass of fuel as a liquid. Wouldn't you need some pressure regulator in either case? I suppose the density of propane vapor would vary considerably with the temperature but as long as it followed the ideal gas law it should be easy to compensate for. mike ------------------------------ From: robert dingli Date: Wed, 27 Mar 1996 15:56:15 +1100 (EST) Subject: Re: LPG injection Mike writes, > > I was looking at a SAE book on the Natural Gas Vehicle Challenge and > several of the entries used Bosch injectors which I'm guessing are standard > pintle type injectors used in gasoline vehicles. I took a quick glance > at the paper from some Nebraska university and it talked about having > two levels of pressure regulation the final one supplying the injectors at > 100psi (as I remember). It also seemed that they used two injectors per > cylinder to get enough flow. This lead me to wonder what are the reasons > for wanting to inject liquid propane instead of propane vapor. From the > various threads on the subject I gather that there might be some problem > getting the liquid to a vapor at low temperatures. I'd guess that it takes > less injection time to inject a given mass of fuel as a liquid. Wouldn't > you need some pressure regulator in either case? I suppose the density of > propane vapor would vary considerably with the temperature but as long as > it followed the ideal gas law it should be easy to compensate for. Based on some of our work with port injected CNG and propane, The benefits of injecting as a liquid as I see them are: - - inlet charge cooling - - simple multi port control - - no gas carburettor restrictions The technical problems to be adressed: - - any vapourisation within the lines or injector will adversly effect flow The LPG would need to be pumped to a pressure higher than the vapour pressure in the tank to avoid vapourisation due to higher temps/ lower pressure along the lines - - injector lubrication - - injector degradation due to internal cavitation - - inlet charge over cooling Injection as a gas is possible using specialised injectors, but doesn't offer the benefit of intercooling the air stream. Using the vapouriser to cool an air-con system rather than using a compressor would utilise some of the cooling affect. This could be a suitable alternative for some applications. Robert - -- Robert Dingli r.dingli@xxx.au Power and Control Systems (+613) 9344 7966 Thermodynamics Research Labs (+613) 9344 7712 University of Melbourne, AUSTRALIA ** he who dies with the most toys, wins ** ------------------------------ From: dzorde@xxx.au Date: Wed, 27 Mar 96 15:16:29 Subject: injector pulse width Hope someone can help, I have put a TPI of a 305 camaro ('84 of memory) onto a 350 block. The cam is something like a 28/63 (fairly moderate for a mild cam). Does anyone have any idea how much fuel the 305 injectors flow (I think they are Bosch units) ? and the maximum pulse length required for the 350 using the same injectors (using the standard 305 fuel rail regulator)? Is it correct the 305 uses a 38PSI regulator, while the 350 uses a 40PSI regulator ? In fact does anyone have a fuel map printout for either a 305 or 350 they could mail me ? It may make it easier to start setting up the map. Any help appreciated Dan dzorde@xxx.au ------------------------------ From: Mark Boxsell Date: Wed, 27 Mar 96 19:06:40 +1000 (EST) Subject: Re: Multi Spark Ignition... At 10:41 PM 26/03/96 GMT, you wrote: > Has anyone here ever played with multi spark ignition? Where instead of firing >once the plugs fire 5 to 20 times very quickly. I saw one of them a few days ago >on an S10 chevy, it picked up it's power 40% according to the engine dyno!!!! I >was thinking about making a DIY version, having flutter on 500ns intervals. I >know that it will burn out the ignition coils I have (junk ford coils), I think >that would be a cool ignition inprovement for my Briggs, also I was wondering >for all you people out there that know what you're doing. Is a 6amp @ 100V >transistor enough to switch the power conections to an injector and a standard >ignition coil? > > Thanks, > Jim Staff > > Jim, What most people don't realise with the MSD is that (on a V8) over about 4000 RPM, maybe less I can't remember the actual RPM, the MSD becomes a "normal" single fire CDI. regards, Mark Boxsell MRB Design. ------------------------------ End of DIY_EFI Digest V1 #88 **************************** 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".