DIY_EFI Digest Wednesday, 8 May 1996 Volume 01 : Number 133 In this issue: Info on 3334 Re: 8748 add'l injector controller design Variable Cam Timing, etc... Re: Variable Cam Timing, etc... Injector controller (attached) Reply to: Re: Variable Cam Timing, etc... Re: Injector controller (attached) See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Mark Pitts Date: Tue, 7 May 1996 10:44:42 +-100 Subject: Info on 3334 OK Guys... just realised, woops etc. The reluctor inputs on the MC3334.... with me so far, good, how would the rest fo you drive these inputs digitaly? Right, thats the teezer for the day! Good luck. Mark ------------------------------ From: Frank Parker Date: Tue, 7 May 1996 07:47:35 -0600 (EDT) Subject: Re: 8748 add'l injector controller design On Mon, 6 May 1996, Charles wrote: > Anyway, if anyone's interested I can post a ZIP file with the > schematic and the artwork (printable on a HP laser printer). It's only > about 60Kb compressed. Usual disclaimers about blowing up CPU's > and engines at your own risk, etc. > Next revision is to add a multiplexer to the A/D input (from the > pressure sensor) so that an oxygen sensor may be used for closed-loop > control. > -Charles > I would be interested in the file. Please post. Where did you add the additional injectors?? Pointing straight @ ports or in ducting before throttle body?? You may be interested in the new O2 sensor Jim Conforti and I have found that will work down to lambda 0.75. It allows the possibility of closed loop wot fuel control as oppossed to all normal cpu's which are open loop. This sensor, a Bosch LSM11, is a modified HEGO, not a UEGO, and thus the interface requires relatively simple temp compensation as opposed to the complex circuit for UEGO's. Plus it's about $170. Frank > ------------------------------ From: ShempMoDin@xxx.com Date: Tue, 7 May 1996 16:15:35 -0400 Subject: Variable Cam Timing, etc... Alfa Romeo used a mechanical variable cam timing device for a few years that was as Ed Hernandez describes. It was an oil-pressure driven sprocket on the intake cam. I have it on my 81 Spider that I'm about to part out. Also, regarding solenoid driven valves, I recently read about a new project (don't ask me where) where they were having some success with this. The twist was that rather than having a solenoid open the valve and a spring close it, they used two springs that, at rest, hold the valve at the midpoint of open and closed. Two solenoids were used, one to open it fully, and one to close it fully. Apparantly, this method reduced the total stroke needed on each solenoid, and made it possible to use more efficient solenoids. - - Paul Witek ------------------------------ From: Timothy Coste Date: Tue, 7 May 1996 17:31:29 -0400 (EDT) Subject: Re: Variable Cam Timing, etc... This isn't anything real helpful on how to do this, but I could of sworn I remember researching several articles that were at least from the mid to early eighties, if not earlier, on using solenoid operated valves...at least in a research project. I know power draw was a major concern but I remember that durability was at least as big a concern as power draw or anything else. Has something changed in the last decade, or is it not as big an issue as I remember it being? I do like (and could swear I'd heard of it somewhere before) the half-open idea. More solenoids but each is a lot less worked (more durable and less power) than one big solenoid. Novel approach. Guess I'll have to try and look up the old articles. I think it was for a senior design project now that I'm thinking about it more. Tim Coste tlcoste@xxx.edu ------------------------------ From: cmorris@xxx.com (Charles) Date: Tue, 7 May 1996 20:53:01 -0400 Subject: Injector controller (attached) I got many responses asking for the info... it's attached to this e-mail. This was a "quick-and-dirty" design, so it is not very user-friendly or adjustable. OTOH, most of you seem to know which end of a soldering iron to hold ;) If I get time (changing job and city soon), I'll do a revision with an oxygen sensor input and a temp sensor. I figured that since the air is pretty hot after compression anyway (even with the intercooler), it might be a little rich on a very hot day, but this doesn't cause much power loss according to various sources. Plus the extra fuel will help suppress detonation. My car also doesn't have an O2 sensor (early L-Jetronic), so that's another reason not to go closed loop. Anyway, feel free to use this as a starting point. The pressure sensor is an OMEGA PV139 series (0-30 psig, 0.5-4.5 volt output) which costs about $48. Everything else is cheap. The transient suppressors are 1.5KE33 (33 volt) on the breadboard, but these are unnecessarily large, and now that I think about it, won't fit the pads I selected! Use a P6 series instead (also 33 volt). - -Charles [Contents, fuelinj.zip, deleted due to length. I've placed the entire post on ftp://efi332.eng.ohio-state.edu \ /pub/diy_efi/reader_contributions/inj_controller_cmorris@xxx.com (line broken for clarity) -- jsg] ------------------------------ From: RABBITT_Andrew@xxx.au Date: Wed, 8 May 1996 09:13:38 est Subject: Reply to: Re: Variable Cam Timing, etc... Lotus have a Electronic-over-Hydraulic valve actuation system which I think they use for cam profile development. I think it was a spin off of their active suspension technology (really!) and according to sources, they could 'square-wave' the valve timing to more than 4000 rpm! There might be some SAE papers on the project. Power consumption and complexity were big hurdles, hence its use only in the test cell. Andrew Rabbitt oecar1@xxx.au From: (Timothy Coste) tlcoste@xxx.edu:smtp Date: ## 05/07/96 17:31 ## This isn't anything real helpful on how to do this, but I could of sworn I remember researching several articles that were at least from the mid to early eighties, if not earlier, on using solenoid operated valves...at least in a research project. I know power draw was a major concern but I remember that durability was at least as big a concern as power draw or anything else. Has something changed in the last decade, or is it not as big an issue as I remember it being? I do like (and could swear I'd heard of it somewhere before) the half-open idea. More solenoids but each is a lot less worked (more durable and less power) than one big solenoid. Novel approach. Guess I'll have to try and look up the old articles. I think it was for a senior design project now that I'm thinking about it more. Tim Coste tlcoste@xxx.edu ------------------------------ From: David Channon Date: Wed, 8 May 1996 17:05:06 +1000 (EST) Subject: Re: Injector controller (attached) > > [Contents, fuelinj.zip, deleted due to length. I've placed the > entire post on > > ftp://efi332.eng.ohio-state.edu \ > /pub/diy_efi/reader_contributions/inj_controller_cmorris@xxx.com > > (line broken for clarity) -- jsg] > > Hi, Can this be decoded as I do not have MIME compatable tools, Thanks. Cheers David. - -- - ----------------------------------------------------------------- David Channon .-_|\ Department of Computer Science / \ The University of Newcastle \.--._/ NSW, 2308, AUSTRALIA v Email : dchannon@xxx.au URL : http://wwwcs.newcastle.edu.au/Research/VMRG/dchannon.html - ----------------------------------------------------------------- "Beware of bugs in the above code; I have only proved it correct, not tried it." -- Donald E. Knuth ------------------------------ End of DIY_EFI Digest V1 #133 ***************************** 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".