DIY_EFI Digest Saturday, 11 May 1996 Volume 01 : Number 136 In this issue: Re: Variable cam timing Re[2]: Injector controller (attached) Re[2]: Variable cam timing Re: Re[2]: Variable cam timing Re: search Anybody out there? Re: Variable cam timing error in 8748 controller See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Paul Beam Date: Fri, 10 May 1996 08:51:40 -0400 Subject: Re: Variable cam timing Based upon Ed's explanation, it seems to me that what is needed is a magnetic coupler or clutch on both the crank and and cam(s). Under computer control, you could allow the cam or the crank to slip momentarily thus changing the phase of the cam. With a DOHC, you could completely adjust the phase of both the intake and exhaust. Just an observation from a dumb EE. Paul R Paul Beam Computer Systems Engineer Johnson Bible College 7900 Johnson Drive Knoxville, TN 37998 (423) 573-4517 (423) 579-2337 fax ------------------------------ From: "Terry Sare" Date: Fri, 10 May 96 08:15:20 CST Subject: Re[2]: Injector controller (attached) I asked John S Gwynne about the mime format and he suggested mpack and munpack for Unix. Turns out there is a version of munpack for DOS available that did unpack the file on the archive. Following is a mime faq that has pointers to the files and also a mail system. http://www.cis.ohio-state.edu/hypertext/faq/usenet/mail/mime-faq/mime0/faq.html The actual mpack file is here in various flavers. ftp://ftp.andrew.cmu.edu/pub/mpack/ Terry At 03:55 PM 5/9/96 -0700, you wrote: >You wrote: > >> >> Yes the files are available, but unfortunatly they appear to >be in a format that many cannot read/decode. If some one would be so >kind as to make this available as a normal .zip file it would be >appreciated. >> >>BTW: Pkunzip, Winzip, Extract, & Esscode all do not recognise the >format that this file is in. > > Strange! I encoded it with PKZIP, and used Netcom's NetCruiser mail >utility to send it as an attachment. I'm not extremely knowledgeable >about PC's (although I have designed embedded 80C86 systems ;) >so if someone can sort this out, please do so! >-Charles > WinVn can decode MIME files. TurboDave Less Maintenance, More Performance. ------------------------------ From: jfaubion@xxx.mil (jfaubion) Date: Fri, 10 May 96 10:47:35 cdt Subject: Re[2]: Variable cam timing Ok so if we use a clutch or coupler to allow it to slip this would provide a way to retard the cam but how do we then make up the difference again?? John ______________________________ Reply Separator _________________________________ Subject: Re: Variable cam timing Author: diy_efi@xxx.edu at cs-smtp Date: 5/10/96 9:47 AM Based upon Ed's explanation, it seems to me that what is needed is a magnetic coupler or clutch on both the crank and and cam(s). Under computer control, you could allow the cam or the crank to slip momentarily thus changing the phase of the cam. With a DOHC, you could completely adjust the phase of both the intake and exhaust. Just an observation from a dumb EE. Paul R Paul Beam Computer Systems Engineer Johnson Bible College 7900 Johnson Drive Knoxville, TN 37998 (423) 573-4517 (423) 579-2337 fax ------------------------------ From: Jerry Wills Date: Fri, 10 May 1996 11:40:05 -0700 Subject: Re: Re[2]: Variable cam timing Ed wrote plenty, we just need to put the pieces together. Here's my 2 cents I've read a couple of SAE papers on "Valve Events", one on the 2.2 dodge turbo motor, and the other was from volvo or saab. these papers had pumping loop diagrams and tried different IVO,IVC,EVO and EVC, with varied RPM and only a few of these events make the BIG difference , and only within a certain range. I've always liked the "Rhoads Lifter" for you old pharts, which is a hydraulic lifter with to much bleed at low speed, they are noisy, but it works, to reduce lift and overlap at lower rpms. Production tolerances, noise and possible valve-to-piston connection was intimated as the reason the factory has shelved it. My first thought is for DOHC motors is electric motors to run the separate cams and you could phase, all you like. Might be a power problem, but this is DIY. and alternators put out lots a current these days, at some cost in power. any sort of clutch or slipper for phasing will need some good stops so the valve-to-valve or valve-to-piston events are very difficult to create. The production tolerance problem is hard for me to quantify, as the tolerances have gotten much better in motors in the last 5-10 years , but you can still blueprint motors, so we should be able to build a few parts to a high tolerance, for a project. I think Ed was referring to the solenoid lifter, in this case. Food for thought, 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 90's cowboys, ride iron horses, and punch Deer!!! You done violated Physics, BOY! Assume the position..... (Rider 5/92) ------------------------------ From: LotusM50@xxx.com Date: Fri, 10 May 1996 16:37:13 -0400 Subject: Re: search In a message dated 96-05-09 08:00:37 EDT, you write: >> Has anyone heard of a company called "Simple Digital Systems" >> >> I was in search of a way to contact them, phone number, address etc. >> >> >> Thanks >> >> Steve >> >Look in Turbo mag. They have ads in there. I'm @xxx. >Email back if can not find. fp > > They also have ads in Grassroots Motorsports ------------------------------ From: Peter Shoebridge Date: Fri, 10 May 1996 16:23:53 -0600 Subject: Anybody out there? Has this list just gone quiet or have I been removed from it? I haven't had any mail for a week or two. Peter ------------------------------ From: marchil@xxx.net (Alain Marchildon) Date: Sat, 11 May 1996 00:57:02 GMT Subject: Re: Variable cam timing OK ED's speech was very good and informative. If you want some more explanation on the future of variable valve timing you should look at an article that appeared in the July issue of Turbo & Hi-Tech Performance. They describe an electronic valve actuated by solenoids and controlled by two TEC-II unites. Alain Marchildon Marchil@xxx.NET ------------------------------ From: cmorris@xxx.com (Charles) Date: Fri, 10 May 1996 19:25:09 -0700 Subject: error in 8748 controller I just found a screwup in the artwork... one of the crystal leads is not connected to the 8748. (Either pin 2 or pin 3). Also, you need to use a 74HC74, not a TTL 7474, for the flip flop (since the 10K resistors will cause incorrect logic levels at the clock input from the tach line). - -Charles ------------------------------ End of DIY_EFI Digest V1 #136 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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