DIY_EFI Digest Wednesday, May 19 1999 Volume 04 : Number 292 In this issue: Re: O2 sensor and water Re: O2 voltz Re: New Person Hi Steve Re: Mr Helmholz - simple model Re: Mr Helmholz - simple model Engine code Reading Software?? Re: VE tables Re: New Person Current/New ION information Re: Proformance Software Query Re: Current/New ION information Current/New ION information - (resent) Re: SAAB DI coils - was Re: "ION" information ... Re: radiators? test, please delete Re: Mr Helmholz - simple model Re: Current/New ION information Ignition advance, was Re: alternative engines, WARPED Re: alternative engines, WARPED Re: Ignition advance, was Re: alternative engines, WARPED See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 18 May 1999 11:15:24 -0700 (PDT) From: Squash Subject: Re: O2 sensor and water - --- Pat Ford wrote: > I've > cracked then on my landie and subarus ( the subies > are > right at the bottom of the y pipe anything more then > 8" > would flood the outside of the sensor and the > thermal > gradient popped them (they would leak exhaust). the What type of sensor was this? Was it a porcelain or a steel cased one? Andy _____________________________________________________________ Do You Yahoo!? Free instant messaging and more at http://messenger.yahoo.com ------------------------------ Date: Tue, 18 May 1999 11:26:29 -0700 (PDT) From: Mark Wilcutts Subject: Re: O2 voltz Sorry that should be http://vehicle.me.berkeley.edu/~markw/efi/SAE920289/ http://vehicle.me.berkeley.edu/~markw/efi/SAE930352/ On Tue, 18 May 1999 Regnirps@xxx.com wrote: > In a message dated 5/17/99 8:24:20 PM, markw@xxx.edu writes: > > >There are two papers up on my website: > >http://vehicle.me.berkeley.edu/efi/SAE920289/ > >http://vehicle.me.berkeley.edu/efi/SAE930352/ > > > The server says they are not there. > > Charlie Springer ------------------------------ Date: Tue, 18 May 1999 13:51:22 -0500 From: steve ravet Subject: Re: New Person "SPECTRO COATING CORP." wrote: > > Hi - My name is Jason & I recently started subscibing to this list. > > I'm sure I will learn something here as my efi knowledge drops off a cliff > at the ECU connector.(going in - not out ;) > > My current projects are a V8 AWD S10 Blazer & an 8V-71 supercharged & > injected 440 Chrysler (on the engine stand). Ah, the V8 Blazer. One of my favorites. Are you using a full time case or the part time one? Race truck or trail? - --steve > > I'll hang out & watch for awhile. > > Thanks - J - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ Date: Tue, 18 May 1999 15:34:45 -0400 From: "SPECTRO COATING CORP." Subject: Hi Steve Hi Steve - how you doin? >Ah, the V8 Blazer. One of my favorites. Are you using a full time case >or the part time one? Race truck or trail? Actually (i'm still building it) its a street truck in much the same manner as a typhoon. I'm almost done collecting parts for it, & the last major piece I need is the AWD transfer case If I can fit it in I'd like to turbocharge it & use the 7749 ECU - Mike V. says he can cut the chip for it. Thanks for listening - Jason ------------------------------ Date: Tue, 18 May 1999 14:24:39 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Mr Helmholz - simple model >If this opens a whole new box of problems, just ignore. But, I've noticed >what a huge change expansion chambers have had of VE in 2 strokes, and after >seeing the Mercedes Benz GT (Sedan, whatever they call em) with the v-6, and >3 into 1 exhausts, and running 2 expansion chambers (one per side), I just >wonder, how they came up with that... > Is it the shape of the cones or volume that makes a "E.C." work, or >both?. >Grumpy > Both. Megaphones convert velocity to static pressure pretty efficiently. Greg ------------------------------ Date: Tue, 18 May 1999 17:25:59 -0400 From: "Bruce Plecan" Subject: Re: Mr Helmholz - simple model We're talking about EGT at this stage?, right?. How much change in temp is signifigant?. Bruce > The pure model is a ball "resonating volume" with a pipe "tuning pipe" > attached. Changing the temperature changes the local speed of sound within > the resonator - and thus the frequency of resonance changes. Changing the > volume within the resonating volume changes the frequency - larger lower. > Changing the area/length of the tuning pipe changes the frequency. ------------------------------ Date: Tue, 18 May 1999 15:29:51 -0600 From: "Simpson, James H" Subject: Engine code Reading Software?? Does anyone have PC based software (windows or dos) for reading engine codes. I'm looking for Turbo Pascal, Visual Basic or even Assembler Source code. Doesn't have to be fancy. I just need to read the data stream from the TX pin on the diag. connector. My application is early Jeep 4.0 Liter (Renix system). I'm grabbing at straws here. Thanks in advance if you can help. Jim ------------------------------ Date: Tue, 18 May 1999 16:35:40 -0700 From: "Todd....!!" Subject: Re: VE tables Hello David, Is your goal in reducing teh amount of fuel to find that fine line between extra fuel cooling teh conbustion vs. loadin up the cylinder with extra fuel? or what? Just wonderinnnnnnnn........ Thanks! Todd....!! David A. Cooley wrote: > > Ah.. So Peter Wales bud's (Superchips) increased VE to richen the > mixture... > They richened the mixture from 3800RPM and up and it is at 100-105% across > the board... stock was 85-90% > I may set that back and just play with the PE and timing. > > > > An increase in VE requires an increase in fuel as a higher VE > > > indicates more air flow (or a better ability to flow air). > > > > > > A 100% VE means you are pumping 3800cc's of air every 720 degrees. > > > > > > -Mike > > > > > > -----Original Message----- > > > From: owner-gmecm@xxx.edu > > > [mailto:owner-gmecm@xxx. Cooley > > > Sent: Tuesday, May 18, 1999 9:16 AM > > > To: DIY_EFI > > > Cc: gmecm@xxx.edu > > > Subject: VE tables > > > > > > > > > I have a question... > > > My 95 buick LeSabre basically uses the same code, but with different > > option > > > bits set and different table values, as the Supercharged 3800V6. The > > engine > > > is using MAF and no MAP for air flow. It has tons of MAF tables, but > also > > > has VE tables. (Engine efficiency VS RPM). What effect do the values in > > the > > > VE tables have if you change say 80% at some RPM to 95%? > > > increase fuel delivered at that point or decrease it? > > > Thanks, > > > Dave > > > > > > > > ------------------------------ Date: Tue, 18 May 1999 17:58:07 -0700 From: "Walter Sherwin" Subject: Re: New Person >Hi - My name is Jason & I recently started subscibing to this list. > >I'm sure I will learn something here as my efi knowledge drops off a cliff >at the ECU connector.(going in - not out ;) > >My current projects are a V8 AWD S10 Blazer & an 8V-71 supercharged & >injected 440 Chrysler (on the engine stand). > >I'll hang out & watch for awhile. > >Thanks - J Jason, what kind of injection are you running on the 440? Above or below the blower? Does it have a home yet? Walt. ------------------------------ Date: Wed, 19 May 1999 08:15:17 +1000 From: Peter Gargano Subject: Current/New ION information I just found this article by Ph.D. student Lars Eriksson from Link=F6pin= g University, Sweden. The work was done in collaboration with Mecel AB and=20 SAAB Automobile AB. It's dated 25 November 1998. Here is the summary: http://www.fs.isy.liu.se/~larer/Projects/ionint.html And here is the actual article: http://www.fs.isy.liu.se/~larer/Projects/main.html Put simply, this article cites research that says maintaining the peak=20 cylinder pressure at a particular number of degrees (after TDC) will maximise engine efficiency and smoothness. This point is called the peak pressure position (or PPP). The PPP varies with many environmental condit= ions such as inlet air temperature, humidity, etc. PPP can be estimated by mea= suring the ION current, and in particular the "shape" of the ION current. Knowin= g=20 the current PPP value, the ignition timing can be varied to position the = peak=20 pressure at the optimal point.=20 Perhaps a paragraph from the summary better describes the article... > We are studying a method for controlling the spark advance that is bas= ed > on pattern recognition on the ionization current, in a fast inner loop= .=20 > An idealized model of the ionization current, with six parameters, is = fitted > to the measured ionization current. Information extracted from the fit= ted > model is then used to control the spark advance.=20 I'd recommend all interested ION project people look at this article as i= t also summarises much of the research that has been carried out to date. I= t also provides a common information database from which we can all work fr= om. So, we're talking about engine optimisation, not just knock/pre-ignition detection! regards, - --=20 Peter Gargano mailto:peter@xxx.au Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 ------------------------------ Date: Tue, 18 May 1999 18:45:27 EDT From: CEIJR@xxx.com Subject: Re: Proformance Software Query Gar: I have dynomation, but not Engine expert. Be happy to do some runs if I can help. Charlie Iliff ------------------------------ Date: Tue, 18 May 1999 19:19:13 -0500 From: steve ravet Subject: Re: Current/New ION information That's an interesting article. They show the best PPP to be around 15 degrees ATDC, over a range of RPM and load, to maximize torque. Total torque is the pressure integrated over the horizontal component of the crank position, so if the burn rate of the engine varies the PPP could also vary? I wonder if Robert or someone else with a combustion/Heywood book can comment on determining the best PPP (peak pressure position, the crank angle when max cylinder pressure is reached). - --steve Peter Gargano wrote: > > I just found this article by Ph.D. student Lars Eriksson from Link=F6pin= > g > University, Sweden. The work was done in collaboration with Mecel AB and=20 > SAAB Automobile AB. It's dated 25 November 1998. > > Here is the summary: > > http://www.fs.isy.liu.se/~larer/Projects/ionint.html > > And here is the actual article: > > http://www.fs.isy.liu.se/~larer/Projects/main.html > > Put simply, this article cites research that says maintaining the peak=20 > cylinder pressure at a particular number of degrees (after TDC) will > maximise engine efficiency and smoothness. This point is called the peak > pressure position (or PPP). The PPP varies with many environmental condit= > ions > such as inlet air temperature, humidity, etc. PPP can be estimated by mea= > suring > the ION current, and in particular the "shape" of the ION current. Knowin= > g=20 > the current PPP value, the ignition timing can be varied to position the = > peak=20 > pressure at the optimal point.=20 > > Perhaps a paragraph from the summary better describes the article... > > > We are studying a method for controlling the spark advance that is bas= > ed > > on pattern recognition on the ionization current, in a fast inner loop= > .=20 > > An idealized model of the ionization current, with six parameters, is = > fitted > > to the measured ionization current. Information extracted from the fit= > ted > > model is then used to control the spark advance.=20 > > I'd recommend all interested ION project people look at this article as i= > t > also summarises much of the research that has been carried out to date. I= > t > also provides a common information database from which we can all work fr= > om. > > So, we're talking about engine optimisation, not just knock/pre-ignition > detection! > > regards, > --=20 > Peter Gargano mailto:peter@xxx.au > Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 ------------------------------ Date: Wed, 19 May 1999 10:56:54 +1000 From: Peter Gargano Subject: Current/New ION information - (resent) || Sorry about the mangled text (I cut and pasted an 8 bit character || and it stuffed up the rest of the text...). Here it is again... I just found this article by Ph.D. student Lars Eriksson from Linkoping University, Sweden. The work was done in collaboration with Mecel AB and SAAB Automobile AB. It's dated 25 November 1998. Here is the summary: http://www.fs.isy.liu.se/~larer/Projects/ionint.html And here is the actual article: http://www.fs.isy.liu.se/~larer/Projects/main.html Put simply, this article cites research that says maintaining the peak cylinder pressure at a particular number of degrees (after TDC) will maximise engine efficiency and smoothness. This point is called the peak pressure position (or PPP). The PPP varies with many environmental conditions such as inlet air temperature, humidity, etc. PPP can be estimated by measuring the ION current, and in particular the "shape" of the ION current. Knowing the current PPP value, the ignition timing can be varied to position the peak pressure at the optimal point. Perhaps a paragraph from the summary better describes the article... > We are studying a method for controlling the spark advance that is > based on pattern recognition on the ionization current, in a fast > inner loop. An idealized model of the ionization current, with six > parameters, is fitted to the measured ionization current. > Information extracted from the fitted model is then used to > control the spark advance. I'd recommend all interested ION project people look at this article as it also summarises much of the research that has been carried out to date. It also provides a common information database from which we can all work from. So, we're talking about engine optimisation, not just knock/pre-ignition detection! regards, - --- Peter Gargano mailto:peter@xxx.au Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 ------------------------------ Date: Tue, 18 May 1999 19:29:10 -0700 From: Joe Dzura Subject: Re: SAAB DI coils - was Re: "ION" information ... Gar, First, welcome back. I was hoping to hear from you some day! When the O2 meters / kits are ready, put me on the list for 2 sensors with analog modules. I have been hacking my ford EEC V, and when I tear into the exhaust system, I plan on putting 2 extra O2 bungs in. I don't know if I will ever be able to incorporate ION, but I know I will need the wideband sensors to tune the car. Good to hear from you Joe D ------------------------------ Date: Tue, 18 May 1999 18:03:28 -0700 From: "Mike Pilkenton" Subject: Re: radiators? Thanks for the tip Todd. The stock Opel GT weighs in at 2080 pounds. Mike - -----Original Message----- From: Todd....!! To: diy_efi@xxx.edu> Date: Tuesday, May 18, 1999 9:16 AM Subject: Re: radiators? >Hello Mike, > >If ya go to your local auto parts store, they should have a HUGE book >full of pictures of radiators, with the dimensions under each pic! > >Just choose the one you want and maybe put up a bit a cash and it's >yours!! > >LATER! > >Todd....!! >P.S. - COOL project, that car must not weigh more than 1,500 lbs. if >THAT! > >Buddy bought one a while back, was gonna put a s.b. chev or ford in it, >but he didn't have the drive or the desire to even start the project! > >He got the idea to do the mini-vette opel GT after I did my 81 Pontiac >T1000 (Che-Vette) with a 400 s.b.c. and TH375 all outof a big ol impala >wagon... That thing booked and it weighed in at 2,345 after the >install... Used the STOCK rear-end, luckily it wasn't a posi ot I would >SURELY snapped it, it ran fine with the stock rear end, I think it was >like an 8 bolt or so(LOL) it was geared up for the lil 4 banger that it >came with so the 400 was pretty much wrappin out for any period of >distance at about 40 mph! I used an ol chev nova style radiator... >Didn't run a hood at first, but then the base security said somethin >about the hood being safety equipment????? can you BELIEVE it! That's >SO BOGUS!! So I cut the hood where the radiator and stock fan was >stickin up and hittin the hood and pinned it in the front with hood >pins, whalaa, prob solved, except at higher speeds the back of the hood >would tend to rise and flap a bit due to the engine air and fan wind >blowin some SERIOUS cfm underhood! > >LATER! > >Todd....!! >http://www.c-com.net/~atc347/toddlnk.htm >---------- > >Mike Pilkenton wrote: >> >> I know this is a little off topic for the efi list but I'm finishing up my >> 3.1L V6 engine transplant project into my Opel GT and it's time to think >> about cooling. Can anyone suggest a decent OEM radiator that would be >> sufficient for the GM 60 degree V6 and fit in a tight area say about 13 in >> tall by 16 in wide? >> >> Mike > > ------------------------------ Date: Tue, 18 May 1999 22:02:54 -0400 From: Frederic Breitwieser Subject: test, please delete Test ------------------------------ Date: Wed, 19 May 1999 12:12:56 +1000 From: Stuart Baly Subject: Re: Mr Helmholz - simple model >If this opens a whole new box of problems, just ignore. But, I've noticed >what a huge change expansion chambers have had of VE in 2 strokes, and after >seeing the Mercedes Benz GT (Sedan, whatever they call em) with the v-6, and >3 into 1 exhausts, and running 2 expansion chambers (one per side), I just >wonder, how they came up with that... > Is it the shape of the cones or volume that makes a "E.C." work, or >both?. >Grumpy For a blue-smoke, it's the shape more than the volume. Things happen in this order: 1. the piston uncovers the exhaust port, sending a pressure pulse along the exhaust at the speed of sound. The exhaust gas begins travelling along the pipe somewhat slower than this. 2. the pressure pulse reaches the expanding part of the exhaust (i.e. increasing diameter). The change in diameter produces a reflected wave of lower pressure - this low pressure wave travels back towards the engine. 3. The piston, still travelling downwards, uncovers the transfer port. F uel-air mixture starts to displace exhaust gas from the cylinder. 4. The original pressure pulse reaches the reducing part of the exhaust (i.e. reducing diameter). This produces a reflected wave of higher pressure, travelling back towards the engine. 5. The reflected wave from pt. 2 reaches the engine - this draws the exhaust mixture from the cylinder, and in extreme cases, even draws some fuel-air into the exhaust. 6. The reflected wave from pt4. reaches the engine - this pushes the fuel-air back into the cylinder just in time for the rising piston to close the exhaust port off. I'm sure that the real world operation of a two-stroke exhaust system has many many more factors affecting it, and that this is a greatly sanitised version of reality, but it's a start. 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M"" &``````# ````````1@`````XA0```0````$`````````'@`]``$````% 5````4F4Z( `````#``TT_3<``.KW ` end ------------------------------ Date: Tue, 18 May 1999 20:18:40 -0700 From: garfield@xxx.com (Gar Willis) Subject: Re: Current/New ION information On Wed, 19 May 1999 08:15:17 +1000, Peter Gargano wrote: > http://www.fs.isy.liu.se/~larer/Projects/main.html >> "measuring the ION current, and in particular the "shape" of the ION current, >> based on pattern recognition of the ionization current" Hi Peter the ION-hearted. B) Just a few possibly sage observations (I'll leave you to decide :) from a ole fossil who's been gazing in rapt wonder at this area for awhile: You have to constrast and put the presented level of sophistication of these latest Swede papers in perspective, tho, methinks. If you consider where their PRACTICAL implementation came from (the original Saab patent tells the story; yes, the one with the schematic). And it began as a means of detecting misfire and providing cam decommutation, to eliminate the need for a cam sensor. If you look at the initial deployment from '90-'92, it did NOT provide for detonation detection. Next step: if you look at the follow-on system that replaced it in their Turbo cars, the so-called Trionic system that was intro'd in '93, and has been their mainstay ever since (looking carefully at their documentation is all that's really necessary), you'll find that while the pre-ignition, misfire, and cam decommutation ARE done within the Trionic module, the knock detection is NOT. Hmmm, plot thickens, eh? They pick off the raw ionization signal, handle the wee bairn with extreme care, and present it to a fast A/D port on the ECU. That's sorta mutha naitcha's way of saying it's not so easy to even detect detonation without some 'computational horsepower'. Doable, and doable well, judging from the success and lack of further major revisions in the Trionic system, but NOT so easy as to make it something to do in straight mixed-signal within the Trionic module. OK, so where am I going with this? Well, there's a pretty big leap from just being able to DETECT detonation (let's put it this way, to perform pattern recognition sufficient to discriminate between normal and detonating combustion), to being able to determine an order of magnitude more recognition and separate out many MORE and MUCH more subtle variations in the ionization "pattern", so that you can MEASURE things like cylinder pressure, and charge AFR, for example. Now, it's in the very nature of the beast, that you see in these papers quite alot of forward thinking and perhaps speculative thinking/results. But let me just point out one interesting thing to note about the Saab/Swede's publications and even their patents (or the lack of them) concerning their currently deployed system. AFAIK they have never actually shown/said how their *current* robust/practical/deployed system actually determines detonation. All we know is that the ECU ingests the ionization signal; that's it. We don't REALLY know if they do "pattern recognition" or even "spectral analysis" or even simply some sort of mundane filtering. What we DO know is that unlike the conditions in the research papers, their ECUs seem to do this discrimination bloody accurately AND bloody fast. That's why I said I thot you need to keep the level of sophistication being described in these papers, especially these multivariate pattern recognition schemes, in perspective. And also consider how much compute HP was available to the Saab ECUs in '93. Just some practical matters to consider. >I'd recommend all interested ION project people look at this article as it >also summarises much of the research that has been carried out to date. >It also provides a common information database from which we can all work from. There's actually even MORE stuff going on than the picture he paints. The Swedes are going in some interesting directions, but so are the Japanese, and you get a glimpse of that from the patent sifting AND some of the JP papers he DOESN'T site. B) I'll give ya two hints; if you look at the patents on the subject, you'll see LOTS more Japanese work in this area, and in diff. directions, than the Sweded, and much more work than is represented in his paltry references to JP papers. Second hint: scan the titles and authors of the SAE papers on this subject by doing your own search of the SAE documents, NOT via his bibliography In contrast to the Swede papers, OTOH, what you'll find in the JP papers is some GRADUALLY increasing sophistication to detect detonation, for example. And those DO NOT depend on the giant leap to "sophisticated pattern recognition" that the Swede's seem to imply. So finally, what's my point? Well, those papers and the bibliography you suggest above we use as a "common info database", might be fine if we wanted to step into the moving stream of Combustion Ionization research, but for us hobbyist-experimenters, methinks (at least this is true for me; I don't speak for everybody, obviously) that our interest is largely sorta tryna catch up with some of the cool albeit heretofore hidden things in engine technology, that some of the more advanced mfg's have been able to use and benefit from for some time. That's MY interest in ION, and it parallels pretty nicely the history of EGOR as well. Not too many of us are interested in keeping right up with the latest in O2 sensor physical chemistry so as to be able to be a real "practitioner in the art", but I DO know that many of us are interested in CATCHING up at least enough to be able to USE/play-with this better O2 sensing technology, which after all HAS been in use for yearsNyears, but hidden by a cloak of concealment for that long. Sure, we wanna know what's goin on with the latestNgreatest, but nobody's approaching EGOR by tryna catch up with the latest research; we're just tryna figure out how all these other bloaks have been doing for years!!! B) So the same obtains with ION, methinks. Sure, it IS neat and useful to read and glimpse the latest in ionization measurement research, but I warrant most of us are more interested in just GETTING to USE something that works as well as the stuff Saab has had deployed since '93!! And that brings me to my last BIG hint: it's in the JP papers, IMNSHO, that you will find the incremental advances and techniques that will help you to better understand how you could IMPLEMENT a robust detonation detection method. NO, you probly couldn't use the same approach to determine all these advanced parametric extractions that the Swede papers are discussing. But hey, there ya go! Take yer pick. B) Now, obviously since I've chosen to be a partial "concealment artist" meself, by being a vendor of electronics in this area (which I do outta necessity, not by preference), I can't tell ya any MORE at this point, cuz then I'd hafta shoot ya. Heh. Suffice it to say that IF you're interested in the more practical/mundane issues of how to make ION work for detonation detection, I recommend a more careful, balanced look at ALL the papers, and in particular that means the Japanese work. End of diatribe. >So, we're talking about engine optimisation, not just knock/pre-ignition >detection! Ah yep, pretty exciting, eh? The moment I read the first papers on this stuff, I too fell in LUV. That's why I thot it was completely appropriate to anthropomorphize this tecnology as a "beautiful lady named ION". Especially for an electrical type, the very idea of using the spark plug as a major sensory window into the combustion chamber, AND be able to tell so MUCH from interpreting the ionization picture is appealing enough to have an aura of beautific sublimnity. B) For the present, I'm sure many of us would be content to hear ION reveal her secrets about the mystery of detonation, but it IS neat to think that this one magical song may be just the beginning of her wispering much more poetry in our wondering ears. And to think, all this was lurking on the other side of the bloody spark-plugs!! Sheesh. B) Gar ------------------------------ Date: Tue, 18 May 1999 23:06:41 -0700 From: Aaron Willis Subject: Ignition advance, was Re: alternative engines, WARPED At 12:47 PM 5/18/99 -0400, you wrote: >Just use manifold vacuum. Carb vacuum is ported so there is no vacuum at >idle. This can help or hurt the idle quality. Try it and see. > >Gary Derian > You sure about that? I have always understood that a vac advance can reads ported vacuum in order to affect a curve that begins as the throttle is opened and increases as more throttle is applied, up to the point at which all vacuum (manifold and therefore ported as well) fades under heavy throttle openings, at which point the advance will decline again and the engine will see only mechanical advance. This is apparently to provide extra advance for economy at part throttle. Anybody who can further illustrate this concept, please do because if I am wrong here I'm going to have some serious rethinking to do! Aaron Willis ICQ #27386985 AOL IM: hemiyota http://surf.to/garage-te51 Garage TE51 International ------------------------------ Date: Wed, 19 May 1999 04:02:50 EDT From: EFISYSTEMS@xxx.com Subject: Re: alternative engines, WARPED Hi Todd, I think it's great you have noticed all the bore/stroke combos for some of the chevs,,,,,,,,,somehow, someone at chrysler read grumpys or smokeys book about rod ratio and never learned anything else.....yes the right bore/stroke combo was discovered by chrysler and they tried real hard with the rod ratios,,,,,and if you ever noticed even most cam manufacturers even got the cams right.....single pattern cams with higher rod ratios,,,,,,but the short turn wasn't in the chrysler wedge head,,,there was a belief that there was no mass in the exhaust so design wasn't critical,,,,,,Ford did the same with the Cleveland heads....and yes it's all been fixed(somewhat) these days with the aftermarket stuff.......but you still have to have scavenging(unless it's a turbo or supercharged or restricted intake apps)...I don't exactly know where I'm going with this thread except to say rod ratios equate to a time constant and so does exhaust port flow and cam timing,,,,they can all work together or fight each other..... - -Carl Summers In a message dated 99-05-18 11:16:35 EDT, you write: << Date: 99-05-18 11:16:35 EDT From: atc347@xxx.!!) Sender: owner-diy_efi@xxx.edu Reply-to: diy_efi@xxx.edu To: diy_efi@xxx.edu All you mentioned is foreign to me... I am not of that era and have no friends with any of the good ol flat heads... Do have a friend with a couple a Hemi's buit they're all 426's and souped in the ol Cuda's... 28 mpg seems UNREAL to me right now.... What's the trick? throw a one barrel on it and highway gears and a LOT of air in some REALLY skinny tires and MAYBE I'll be in the teen's but I don't see 20 ANYTHING for gas mileage coming outa my pig! As for gear ratio, the goal is to hit red line in top gear when ya cross the finish line, that's the all around goal of gearing for best e.t... As for the AAR 340 in another car, in my mind the AAR Cuda deserves to have it's engine back! It deserves it and it DEFINITELY looks TOTALLY AWESOME! I passed up snaggin an AAR Cuda for $1,000 back in about 1988, STILL kickin myself! I had JUSt bought the BEE so I didn't think I needed another Mopar pig in the shed! The thing sold right before I found out what it was worth! It had a blown engine(Thrown rod) and the heads and 6 pac intake and carbs were stolen off of it, the body was in SUPER shape, it was orange with the black AAR strip kit! still had the turnouts in front of the rear tires as well as the cool 'glas? single scoop hood! As for the 440 turnin the rpm's... FYI, if'n ya don't already know... A small block chev 302 engine's bore is 4 inches, stroke is 3.00 inches A small block chev 327 engine's bore is 4 inches, stroke is 3.25 inches A small block chev 350 engine's bore is 4 inches, stroke is 3.50 inches A small block chev 400 engine's bore is 4.125 inches, stroke is 3.75 inches A BIG block chev 427 engine's bore is 4.25 inches, stroke is 3.75 inches A BIG block chev 454 engine's bore is 4.25 inches, stroke is 4.00 inches If we took, for example, a Big Block chev engine with a 4.25 inch bore, like say a 454 block and DE-STROKED the crank to in between a 327 and 350 at say about a 3.37 stroke, this would give you the dimensions of a 383 Mopar engine! Can you imagine what a cehv 454 destroked to a shorter stroke than a 350 chev would rev like? Well, you know what it could sound like whenever ya here a 383 Mopar engine rev! Super quick! Then ya have the 440 Mopar which comes from the factory with a 4.32 inch bore and a 3.75 inch stroke (Same as the 427 Chev b.b.) A 400 Mopar engine has even a BIGGER bore than the 440 at 4.34! AND the stroke is the same as the 383!!! which again is abotu 3.38 inches! a 400 Mopar engine is like taking a 454 engine with a 4.25 inch bore, boring it out .090, which is hardly ever done on the B.B. Chev due to cyl wall thickness and safety THEN DE_STROKIN the sucker to a shorter stroke than a 350 chev!! The 400 Mopar is where it's at if ya want a high revvin engine! What some people do to the 400 Mopar is throw the 3.75 inch 440 crank into the 400 block and create a REALLY lightweight internal 451 stroker motor! http://www.musclemotors.com sells the kit for this build in various forms and completedness... One of the GREAT things about these Mopar engine's is that they cost less at the bone yards than even the s.b. chevs or Ford's, I assume due to the law of supply and demand, more people but chev's and Fordsouta the yards than Mopars... I picked my 440 up for $135 at the local Pic-Ur-Part self-help junk yard... Rebuilt it and had it in the car for about $1,300 TOTAL including the price of the junkyard engine! Sure I'm only runnin low 13's so far, but I have my probs and it's not the engine itself, it's the ignition system, i.e. cheap plugs and wires, as well as carburetor 'issues'... Tippin the scales at 3,710 lbs. without driver doesn't help things much! Will be in the 12's soon, after installin new Accel 8 mm wires and accel non resistor plugs and buddies race 750 and losin the rest of the junk in the car after a good cleanout.... Hopefully she'll hook up this time, maybe use some VHT this time as well!! And some octane booster or race fuel! LATER! Todd....!! http://www.c-com.net/~atc347/toddlnk.htm CLsnyder wrote: > > ----- Original Message ----- > From: Todd....!! > To: > ------------------------------ Date: Wed, 19 May 1999 04:09:44 EDT From: EFISYSTEMS@xxx.com Subject: Re: Ignition advance, was Re: alternative engines, WARPED Hi all, I could be wrong at this, but what I have seen is, ported vacuum is dead at idle, because it is above the butterfly....and as throttle is increased, vacuum is generated at the "port" and does not go away at full throttle,,,,,great for emissions but terrible for performance,,,,,the same for MPG.... - -Carl Summers In a message dated 99-05-19 02:14:13 EDT, you write: << > You sure about that? I have always understood that a vac advance can reads ported vacuum in order to affect a curve that begins as the throttle is opened and increases as more throttle is applied, up to the point at which all vacuum (manifold and therefore ported as well) fades under heavy throttle openings, at which point the advance will decline again and the engine will see only mechanical advance. This is apparently to provide extra advance for economy at part throttle. Anybody who can further illustrate this concept, please do because if I am wrong here I'm going to have some serious rethinking to do! Aaron Willis ICQ #27386985 >> ------------------------------ End of DIY_EFI Digest V4 #292 ***************************** 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".