DIY_EFI Digest Saturday, May 1 1999 Volume 04 : Number 255 In this issue: [none] Re: Fuel injection plugs Re: atomization enhancement Re: Fuel injection plugs Re: Flame - Not Re: cam grinds for SC Re: Fuel injection plugs Re: Transplant Re: Flame - Not Re: Fuel injection plugs Re: Fuel injection plugs Re: atomization enhancement Re: atomization enhancement Re: Fuel injection plugs Re: Transplant Re: Fuel injection plugs Re: cam grinds for SC Re: Direct Injection Direct Injection - Stratified NC hybrid setup/coolant blows heater core/how to avoid? torque convertor choice? Re: atomization enhancement Re: atomization enhancement Re: Fuel injection plugs Re: Fuel injection plugs Re: Flame - Not Re: NC hybrid setup/coolant blows heater core/how to avoid? 1227749 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sat, 1 May 1999 06:10:05 -0400 From: jsg@xxx.edu Subject: [none] Subject: [admin] List services (automated monthly post) This message is post monthly as a reminder of the available list services. For help: Send "help" to Majordomo@xxx. To post: Send to "[list name]@xxx.edu" To subscribe: Send to Majordomo@xxx.edu subscribe [list name] [your email address *only* if different than your "From" address] To unsubscribe: Send to Majordomo@xxx.edu unsubscribe [list name] [your *registered* email address if different than your "From" address] The archive to each mailing list is available through the following sources: 1) WWW. http://efi332.eng.ohio-state.edu/ 2) ftp. ftp://efi332.eng.ohio-state.edu/ 3) Majordomo. Send "index [list name]" to Majordomo@xxx. You will find a file "archive_date_index" whose contents show the period covered by each of the archive files "archive_num_*". Digest mode is available for each mailing list. Send "lists" to Majordomo for a listing a mailing lists served. To switch to the digest mode, unsubscribe from the regular list and then subscribe to the digest version (i.e., diy_efi-digest). WWW site (for diy_efi and efi332): http://efi332.eng.ohio-state.edu/ now mirrored at http://tech.buffalostate.edu/efi Please send information to be added to this posting to jsg@xxx. John ------------------------------ Date: Sat, 01 May 1999 06:15:03 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Raymond C Drouillard wrote: > I don't argue with the above. What I am saying is that if you run it at > max VE without throttling it, you will generate MUCH more power than you > need. If you throttle it, you will not have a good VE. Throttling works > by lowering VE. I agree. But do you have to throttle? > Agreed. There is no throttling with a properly used CVT. You reduce > power by LOWERING THE RPM of the entine to the point where it is > producing the desired power. > > The engine is constantly at WOT, and the power output is controlled by > controling the engine speed. Um I don't agree with this, with a perfect cvt the change in applied power would be due to gearing changes. > I am comparing a throttled engine at the speed of max VE with an > unthrottled engine that has been slowed down enough to reduce the power > to the desired level. Based on that, my statement is correct. Your absolutely correct. Our disagreement seems to be in the function of the cvt itself. > IF YOU RUN AN ENGINE AT MAXIMUM VE WITHOUT THROTTLING IT, YOU WILL GET MORE > POWER THAN YOU NEED, AND NOTHING YOU CAN DO WITH THE TRANSMISSION (besides > wasting the power through friction) WILL REDUCE THE POWER LEVEL. > If you are cruising at a speed that requires 25 HP to maintain, and your > engine is capable of putting out 200 HP, you have to either throttle it > or run it at a speed where it only generates 25 HP. You CAN NOT run it > at its peak VE point or its peak power point and only generate 25 HP > unless you throttle it. > There, I said the same thing in several different ways. Hopefully, the > concepts won't be misunderstood. Please read it carefully before writing > a rebuttal. I have read it carefully and try to do so with all the messages I reply to. I enjoy learning the theory involved here. Which is what I am trying to do, learn. There are few perfect students and I, unfortunately, do misunderstand concepts. If you feel it is a chore to respond to my comments, you don't have too as much as I do enjoy the conversation. When we are in first gear of a typical car today, we have a high (numerically) gear ratio which increases the effective torque at the driving wheels to get the car going, right? Why isnt the reverse true? With a perfect cvt, there is not limitation on the gearing so we can reduce the engine torque through very low (numerically) gearing, is there a reason this is not feasible with a perfect cvt? By these means we could also control the load on the engine... James Ballenger ------------------------------ Date: Sat, 01 May 1999 06:17:06 -0400 From: James Ballenger Subject: Re: atomization enhancement "David A. Cooley" wrote: > Most injectors will go to 80 maybe 100 PSI differential tops across them > before they will either stick fully open or stick fully closed. How does the increased pressure affect control of the pulsewidth, if at all? James Ballenger ------------------------------ Date: Sat, 01 May 1999 06:21:53 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Howard Wilkinson wrote: > The reason for the stepped transmission is to increase gear range > beyond what the belt drive can provide.... you'd probably have to use > an axle ratio of 1x (not available as far as I know) to get high > enough gearing to load an engine down under virtually any conditions Could a second belt system be employed in connection with the first to offer a wider range of ratios? I guess it could be 1:1 and inactive until engaged by rpm/vacuum and then be able to increase or decrease the ratio as neccessary. James Ballenger ------------------------------ Date: Sat, 01 May 1999 06:50:15 -0400 From: "Peter D. Hipson" Subject: Re: Flame - Not Your typical (cheap, non-ohv) 4-stroke lawnmower engine is a flat head--the head has nothing but holes for plugs, no valves. The valves are mounted in the block instead. At 02:24 PM 4/30/99 -0400, you wrote: >Robert, > >I am more of an ignoramus than most on this list- just a fresh >mechanical engineering graduate. Could you detail what a *flathead* >motor design consists of? > >Thanks! Thanks, Peter Hipson (founder, NEHOG) 1995 White NA Hummer Wagon ------------------------------ Date: Sat, 1 May 1999 07:32:06 EDT From: EFISYSTEMS@xxx.com Subject: Re: cam grinds for SC In a message dated 4/29/99 7:13:04 AM Pacific Daylight Time, jsg@xxx.com writes: << Subj: cam grinds for SC Date: 4/29/99 7:13:04 AM Pacific Daylight Time From: jsg@xxx.com Sender: owner-diy_efi@xxx.edu Reply-to: diy_efi@xxx.edu To: diy_efi@xxx.edu I'm about to install a Vortech supercharger on my SBC 305 TPI, and I'm thinking about changing cams too. The vortech FAQ has this to say about cams: 4) What is the correct cam to run with my supercharger? Cam selections are best discussed with the various cam manufacturers. Many people select cams which are not the correct choice for centrifugal superchargers. When discussing the cam with a manufacturer make sure they understand a Turbo cam or a cam for a Roots style supercharger is different than a centrifugal cam. Generally speaking the supercharger and the cam do the same thing (increase volumetric efficiency), be cautious of choosing a cam that has large amounts of lift and duration. Ideally for a street application retaining decent idle, emissions and drivability are important, for this reason we suggest a "moderate" camshaft. Given the choice between two cams we suggest the milder of the two for street applications. Of course that is of little help, and I would like some idea of what's going on before contacting manufactures. So, what does make for a good cam for applications like this? How do these cams differ from turbo or roots specific cams? john >> Hi John, Man, where do I start........this thread could be extremely long but I'll try to keep it to the point.....Turbo cams diff from supercharged cams for two major reasons.....backpressure between the exhaust valve and turbo and spool up times,and truely a bunch more incidental ones....but that's a whole different discussion...... As for the supercharged stuff here goes......There is probably a very good cam for your app available off the shelf or if not can be custom ground at a reasonable cost,,,but I will need more info from you to recommend one......As for some experience on the subject I would like to share with the group this regarding lobe separation and overlap cycles.......overlap cycles affect octane requirements and fuel efficiency...... example....540 bbc 7.5:1 compression 100 octane fuel 775 hp 5500 rpm 11 lbs boost. engine would not detonate on the dyno with 92 octane but if loaded for long periods of time(boat) would begin detonating within 7-8 minutes unless we used 100 octane....cam was 222-226 @xxx.Customer wants to run 92 octane, when decreased timing far enough to eliminate detonation EGT's would go too high for extended use....advise of decrease in fuel mileage and install cam 246-254 @xxx. engine makes the same 775hp at 5500 but now is only 8lbs of boost. Intake air temps within 10 degrees of each other but requires almost 20% more fuel(using Horiba airfuel meter and allowing an offset for the overlap to scew the sensor readings) Egt's are now 1375-1400 and stable on 92 octane for unlimited periods of time........The overlap cycle helps cool the surface temp of the combustion chamber and piston and exhaust valve...but results in a waste of charge out the exhaust.......same customer later wants 1000 hp, turn boost up to 11 lbs and engine makes 980hp at 5600 but jumped from 11lbs boost at 5600 to 14lbs of boost at 5800.....VE of engine fell off at 5600 and supercharger did not.....Install new cam with exact same overlap cycle but intake valve closing event 20 degrees later.....engine makes exact same power to 5600 but makes 1184 hp at 6100 rpm at same 11lbs of boost......This told me my heads were flowing as much air as the supercharger could push(pressure had equalized in the cylinder in comparison to the manifold) until there wasn't enough time(RPM vs valve event) to continue to fill.....again required 100 octane fuel to make the higher horsepower but was very stable and hey how long does it take to change pulleys to run 92octane????? As far as cams go in reference to centrifugal vs. roots....with a roots type the only thing holding the air back is the throttle blade,,,but with a centrifugal it is also rpm dependant and the wrong camshaft will produce less torque at low speeds than you probably had stock.......and in reference to the cylinder head stuff, if I had poorer heads on this app I would have gained hp by adding intake closing event time....another way to help a poor environment such as a stock engine......I have ended up with as high as 121LC cams on some supercharged street engines just to fill the cylinder more without giving up the effiency.....but you might think about an EGT guage if your gonna tow.........I know I have just touched the surface of this conversation but will attempt to answer any questions I can.....I don't know everything there is to know about every app regarding supercharger cams but am more than willing to help with the experiences I have had. John, I would like to know any mods done to your engine,,,,static compression ratio,,,,rpm band and how much hp you're trying to achieve.....is it going to be a flat tappet hydraulic or hydraulic roller????? Anyway, I hope that helps and I'll try to respond as quickly as possible,,,,,just doesn't seem to be enough hours in the day....it's 4:30 am here and gotta be up soon to tune some stuff at the track....ttyl - -Carl Summers ------------------------------ Date: Sat, 01 May 1999 06:29:50 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Howard Wilkinson wrote: > James: > BMEP is an acronym for Brake Mean Effective Pressure...... It may > be considered to mean the pressure developed in the cylinder by the > combusion process. At low throttle settings BMEP is low, at WOT in > the max torque range BMEP is max....... Actual BMEP values vary > between engines as a result of compression ratio, boosting, camming, > etc. The max torque developed by an engine per cubic inch > displacement is a direct relation to max BMEP. Thus at high RPM BMEP > values are lower than at low RPM due to lower induction efficiency, > although the power output BHP is greater. In general engines live > longer operating at lower BMEP..... H.W. Thanks for the explanation Howard. It would make sense since most of the timing is in by the time todays engines reach peak torque so that at this point an engine would be doing the most negative torque btdc. A lot more bearing wear would probably result. It seems if we were building engines for performance at that one point, we could minimize it though. Also high rpm failures and varying loads due to changing engine speed would no longer be a factor. James Ballenger ------------------------------ Date: Sat, 1 May 1999 07:07:55 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Transplant >Nah - some insane whacko is building a unique engine from various scrap parts >and ancient hot rod ideas. When it get's finished, it will be vaguely fordish >and definitely unusual and maybe not too expensive. Nice flame, Bob!! Greg > > >Date: Fri, 30 Apr 1999 14:24:55 -0400 >From: H Villemure >Subject: Re: Flame - Not > >Robert, > >deleted stuff > >And about your Mach 1- what transplant? The Cobra 427? Talk about torque >monster... > > >1963 Ford C-600 Prison Bus Conversion "Home" >1971 Lincoln Continental 460 "Christine" >1972 "Whale" Mustang awaiting transplant >1978 Dodge Long Bed Peeek Up "Bundymobile" > >Habaneros - not just for breakfast anymore ------------------------------ Date: Sat, 1 May 1999 07:07:57 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Flame - Not >Flatheads....... Well don't let's forget Briggs & Stratton, Tecumsa, >Kohler........ H.W. > Or Indians! (The engines, not the tribe!) Greg ------------------------------ Date: Sat, 1 May 1999 07:11:02 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >Aaron: > Unfortunately I have yet to see a water injection system that I >like..... Stay tuned. also up here there are not enough months when water >injection is practical. Stay tuned. (Do not adjust your set!) Greg H.W. ------------------------------ Date: Sat, 1 May 1999 07:29:17 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >You also commented about noise in the FE engine with .035 lash..... it >wasn't any louder than most solid lifter engines, and was in a 2 ton >cab over truck so lifter noise wasn't noticed...... supprisingly some >of the Ford factory specs for lifter adjustment on some of the stock >FE engines with solid lifters which were high performance engines in >the early & mid 60's were at or very close to this gap. You will find >this on some of the 390, 406, and 427 engines I believe..... Three >duces, solid lifter cam, and 400+ hp. Those were real engines!! >H.W. > The 421 Poncho and the 413 Max Wedge III each had it all over the 390/406 FE's! Whether your expert ear heard it or not, the take up ramps on solid lifter cams vs. hydraulic lifter cams are entirely different! The initial ramp on a hydraulic cam is quite quick, so as to set the check valve in the lifter closed. The initial ramp on a solid lifter cam is much gentler, so as to take up the lash with minimal impact on various valve train parts. If you run a solid cam with hydraulic lifters, the timing and lift will be inconsistent--generally less duration and lift at higher engine speeds, which is about the opposite of what you want. If you run a hydraulic cam with solid lifters, you subject your entire valve train to a lot of unnecessary impact--Which is OK I guess, if you have no respect for your engine, an infinite supply of money, or do not rev the engine to the potential of the cam you are running. But--I am sure that you knew that, and just hadn't told us yet! BTW--please start snipping the messages you reply to--not only does it take a lot of bandwidth when you do not do this, it takes forever do do it for you when replying! Regards, Greg ------------------------------ Date: Sat, 1 May 1999 08:11:16 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: atomization enhancement >"David A. Cooley" wrote: > >> Most injectors will go to 80 maybe 100 PSI differential tops across them >> before they will either stick fully open or stick fully closed. > > How does the increased pressure affect control of the pulsewidth, if >at all? > >James Ballenger Flow through an injector per unit time will vary directly with the square root of the pressure across it. "Pressure across it" means the arithmetic difference between the gauge pressure in the fuel rail and the gauge pressure in the manifold at any given condition. At very short pulse widths, the higher pressure will affect the opening and closing characteristics of the injector enough that things will not be quite this simple. Kinsler FI has done a bunch of work with running injectors at high pressures. Regards, Greg ------------------------------ Date: Sat, 1 May 1999 10:32:22 EDT From: CEIJR@xxx.com Subject: Re: atomization enhancement James: Although we haven't done extensive testing yet, we have benched some injectors at varying pressures and pulse widths. As we suspected before setting up the bench, the generally accepted formulas are not very accurate. An increase in pulse from 2 ms to 4 ms does not exactly double flow. Nor does flow vary directly with the square root of the pressure. The dynamics of opening and closing are affected differently by pressure for different injector types and sizes, and obviously flow is affected by the percentage of the pulse a particular injector takes to open and close. Math is good for ballpark estimates, and injector selection, but bench testing and then dyno testing are unfortunately necessary for final tuning. Charlie Iliff ------------------------------ Date: Mon, 3 May 1999 07:25:03 -0700 From: "Howard Wilkinson" Subject: Re: Fuel injection plugs James: There's got to be a million ways of accomplishing this...... The regular transmission with steps is more efficient than the belt drive. The idea here is that the belt drive provides the continuous stepless effect and the transmission provides ranges..... perhaps it isn't necessary, but I am assuming that at very light loads extreme high gearing will be required to load the engine enough to hold it down to the desired speed at WOT. This may not be necessary if you are willing to use a hybrid system which uses a conventional throttle when you get beyond your target operating range. That is to say if you optimise for typical highway driving so that you can gear enough to hold the engine down, probably on downgrades you'll have to resort to conventional throttling anyway. My thinking is that if you provide a high enough gear ratio to accomplish the objective of nearly always being able to throttle with the transmission, it will at times be necessary to gear down further than your belt drive transmission allows for power, just as gravity may overcome your ability to throttle with load at the other end. H.W. - -----Original Message----- From: James Ballenger To: diy_efi@xxx.edu Date: Saturday, May 01, 1999 5:22 AM Subject: Re: Fuel injection plugs > > >Howard Wilkinson wrote: > >> The reason for the stepped transmission is to increase gear range >> beyond what the belt drive can provide.... you'd probably have to use >> an axle ratio of 1x (not available as far as I know) to get high >> enough gearing to load an engine down under virtually any conditions > > Could a second belt system be employed in connection with the first to >offer a wider range of ratios? I guess it could be 1:1 and inactive until >engaged by rpm/vacuum and then be able to increase or decrease the ratio >as neccessary. > >James Ballenger > > > ------------------------------ Date: Mon, 3 May 1999 07:27:20 -0700 From: "Howard Wilkinson" Subject: Re: Transplant Jim: Please explain the term "floating rod bearings"......... I've never heard it before...... The only "floating rod bearings" I've experienced are those which spin between the bearing and the rod.......... Definitely a bad deal.... forshadows doom! H.W. - -----Original Message----- From: Jim Davies To: diy_efi@xxx.edu Date: Saturday, May 01, 1999 12:24 AM Subject: Re: Transplant > > >On Sat, 1 May 1999, Robert Harris wrote: > >> Nah - some insane whacko is building a unique engine from various scrap parts >> and ancient hot rod ideas. When it get's finished, it will be vaguely fordish >> and definitely unusual and maybe not too expensive. >> >Floating rod bearings too? > > > ------------------------------ Date: Mon, 3 May 1999 08:15:11 -0700 From: "Howard Wilkinson" Subject: Re: Fuel injection plugs Greg: Snip....... As regards your comments about cam ramp angles...... I was aware of that issue and don't regard it as relevant at the extreme lash involved...... 50K+ trouble free miles on this engine in a single axle semi tractor (391 engine) bear that out. Life expectancy of a gas engine in this application isn't much over about 80K no matter what engine you use, and it is still running strong and has been trouble free. H.W. ------------------------------ Date: Sat, 01 May 1999 11:03:00 -0500 From: dave.williams@xxx.us (Dave Williams) Subject: Re: cam grinds for SC - -> To my mind, roots type or centrifugal type superchargers would both - -> benefit from small overlap cams. This is because these are the only - -> engines that have greater intake pressure than exhaust pressure. Too - -> much overlap just blows intake out the exhaust. Scavenging. ------------------------------ Date: Sat, 01 May 1999 11:03:00 -0500 From: dave.williams@xxx.us (Dave Williams) Subject: Re: Direct Injection - -> valve opens. On SEFI when does the fuel inject? It doesn't really matter. The intake port has plenty of turbulence. Most port injection systems are batched; for the few that are truly "sequential", the injector timing can be played with at idle for smoothness or emissions, but at quarter-power you'll be injecting through the whole intake stroke anyway; at full throttle the injector will be on most of the 720 degree cycle. ------------------------------ Date: Sat, 01 May 1999 16:10:03 GMT From: bob@xxx.com (Robert Harris) Subject: Direct Injection - Stratified Try some out of box thinking. The propaganda is that Stratified Charge is to facilitate burning an overall lean mixture thereby increasing milage. The actual working is that a normal to richish mixture is first ignited and this burning charge is then used to ignite a much more reluctant main charge. Using a fuel scavenged pre-chamber ( one where the fuel is shot thru the pre chamber into the main chamber and the ignition takes place in the pre-chamber) , think about using two fuels. The first - thru the prechamber, is an easy to ignite, relatively fast burning fuel that will generate a nice flame jet and readily ignite the main chamber. The next, a slower burning, much harder to ignite main fuel that is admitted to the cylinder in a more normal fashion. What now happens is that the Flame Jet lights off the slower burning main charge rather quickly and fast normal combustion now occurs. The pre-chamber fuel is something like say gasoline. The main chamber is say Methane ( Natural Gas ) for the economy minded. No problem - just a little complication. But suppose that the main mixture was very rich and it was something very hard to ignite - such as a blend on alcohol and nitro-methane? The prime power limiting factor for such blends is how fast and how much can you get the fuel lit off. Even with super energy twin plug systems, much of the fuel does not burn in the cylinder but finishes combustion in the exhaust pipes. The Flame Jet ( directly stolen - its still a stratified charge - just the fuel and mixture considerations have changed ) could probably be used for a significant increase in power. And nothing stops the pre chamber fuel from being something different like gasoline from the main chamber and further, nothing stops you from using mutually incompatible fuels in both chambers, since the only contact with each other will be in combustion. Contemplate gasoline with a heavy hydrazine shot for the pre-chamber and mutually incompatible Nitro-Methane in the main. Massive power effects from both - with no time for the slow incompatibility products to form. This is where learning how and why and not blanketly parroting the latest hype pays off. Its the out of box thinking that violates nothing but would never be thought of that wins races and succeeds well whenever tried. Think about it. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Sat, 01 May 1999 09:15:55 -0700 From: Ross Corrigan Subject: NC hybrid setup/coolant blows heater core/how to avoid? I know this is NC but I"ve exhausted my related Nissan/Datsun list w/ no good info. A few of us have sb chevy V8's and several have experienced heater core problems d/2 higher/greater coolant flows/pressure (I don't know specifically), they've replaced w/ brand new units and halfway thru winding out and leaving another NSX (their ride, mine wouldn't do that;^) their heater core will fail again. They only discussed ways to just bypass the heater core which is simple but I live in the often rainy pacific nw so need heat occassionally throughout the year and would prefer some sort of pressure reducer mini-manifold but I"m not familiar w/ what hardwar is out their or the simplest way to solve this. I'm not sure if it's simply a matter of too much flow or pressure or combo of both that fails them. Mine's still OK but I haven't ran it very hard yet and want to preempt a painful heater core R&R etc. thanks for any and all ideas in advance Ross Corrigan / Vancouver, Canada '80 327ZX IZCC#255, Edmonton Z-car Club #44, British Columbia ZCR Life's a journey, not a destination.. Enjoy the pitstops and maximize the straights mailto:zxv@xxx.ca *New ICQ # 11549358 http://home.iSTAR.ca/~zxv/index.shtml http://207.212.212.139/~corrigan/gearheads/pics/wheels/sirbg.jpg where a Z belongs ------------------------------ Date: Sat, 01 May 1999 09:23:07 -0700 From: Ross Corrigan Subject: torque convertor choice? probably NC as well but I do plan on installing my holley TB 4Di system shortly so it's related to my EFI setup.. My car is in the tranny shop this week and it's a rare time it's out of the car (700R4)so thought I'd run by my present converter and see if you recc'd a different one. Refresher... 3100lb loaded car w/ 206/212 @xxx.050 Xtreme cam, 9.5:1, performer RPM heads, and stock bottom end 327 w/ good flows, ~300flywheelhp anyhow. they dynoed my tranny today and said my convertor is a 1550rpm, my car is a daily year round driver that gets lots of city driving and some hard track days roadracing/and autocross in the summer. Tranny guy seemed to think a 21-2200 stall would be much better suited. Oh yeah, I may bump the cam up a level in the future (possible a roller) but certainly not milder. comments ideers? gains/losses to a 2000+ stall? much mpg loss??, read about the S10 '95+ convertor being a bolt in 2000stall for the 700, my torque would probably bump that to 2200? Should it stand up in my application? I heard they fragged in some Impalas but they're a lot heavier. THe S10 95+ has same internals as the vette's 700R4 convertor if that helps. thanks in advance ! Ross Corrigan / Vancouver, Canada '80 327ZX IZCC#255, Edmonton Z-car Club #44, British Columbia ZCR Life's a journey, not a destination.. Enjoy the pitstops and maximize the straights mailto:zxv@xxx.ca *New ICQ # 11549358 http://home.iSTAR.ca/~zxv/index.shtml http://207.212.212.139/~corrigan/gearheads/pics/wheels/sirbg.jpg where a Z belongs ------------------------------ Date: Sat, 1 May 1999 12:35:19 -0400 From: "Bruce Plecan" Subject: Re: atomization enhancement >Caterpillar has carried this to extremes and > >has some diesel engines running ungodly high pressures....I don't know > >the exact figures. On our International it's 2,800-3,200 PSI. But, this is diesel. > > I propose changing out the injectors on my vehicle with injectors > >rated for lower flow, and raising the pressure to compensate. > >Pressure would be adjusted in "open loop" mode using an exhaust > >analyzer. It has been said that most injectors are rated at pressures > >far above what they are operated at. > > I'm sure this is far from an original idea, and that some of you > >have done it..... How much difference does it make, and what about > >pump load at the higher pressures..... how much increase in pressure > >is required. > > I'd like to hear about peoples experiences and mishaps doing this > > Most injectors will go to 80 maybe 100 PSI differential tops across them > before they will either stick fully open or stick fully closed. Some of the disc type completely lock closed at as low as 90, the pintle "seem" OK to 110, or so. Again this are reported numbers, but the 90 and disc was from a reputable source. Grumpy > =========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > Sponges grow in the ocean... Wonder how deep it would be if they didn't?! > =========================================================== > ------------------------------ Date: Sat, 01 May 1999 12:49:58 -0400 From: "David A. Cooley" Subject: Re: atomization enhancement At 06:17 AM 5/1/99 -0400, you wrote: > > How does the increased pressure affect control of the pulsewidth, if at >all? The pressure on the Pintle or disc (depending on type) will cause the injector to take longer to open once current is applied. It will get to a point where the magnetic force from it's coil cannot overcome the force the fuel is putting on the pintle/disc and it sticks closed, or if the design has the fuel pressure in such a way it aids the opening and closing of the injector, it will reach a point where the return spring cannot close the injector against the fuel pressure, sticking open. =========================================================== David Cooley N5XMT Internet: N5XMT@xxx.net Packet: N5XMT@xxx. Member #7068 Sponges grow in the ocean... Wonder how deep it would be if they didn't?! =========================================================== ------------------------------ Date: Sat, 1 May 1999 13:36:49 -0400 From: Raymond C Drouillard Subject: Re: Fuel injection plugs On Sat, 01 May 1999 06:21:53 -0400 James Ballenger writes: > > >Howard Wilkinson wrote: > >> The reason for the stepped transmission is to increase gear range >> beyond what the belt drive can provide.... you'd probably have to use >> an axle ratio of 1x (not available as far as I know) to get high >> enough gearing to load an engine down under virtually any conditions > > Could a second belt system be employed in connection with the first to >offer a wider range of ratios? I guess it could be 1:1 and inactive until >engaged by rpm/vacuum and then be able to increase or decrease the ratio >as neccessary. > >James Ballenger Gears are more efficient than belts. ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] ------------------------------ Date: Sat, 1 May 1999 13:35:48 -0400 From: Raymond C Drouillard Subject: Re: Fuel injection plugs >> Agreed. There is no throttling with a properly used CVT. You reduce >> power by LOWERING THE RPM of the entine to the point where it is >> producing the desired power. >> >> The engine is constantly at WOT, and the power output is controlled by >> controling the engine speed. > >Um I don't agree with this, with a perfect cvt the change in applied power >would be due to gearing changes. CHANGING THE GEARING CHANGES THE ENGINE SPEED! THAT IS THE WHOLE POINT! > >> I am comparing a throttled engine at the speed of max VE with an >> unthrottled engine that has been slowed down enough to reduce the power >> to the desired level. Based on that, my statement is correct. > >Your absolutely correct. Our disagreement seems to be in the function of the >cvt itself. A CVT doesn't change the power (besides the ordinary efficiency losses). If you attempt to reduce the torque to the drive wheels by changing the gear ratio, you will either slow down the engine or speed up the vehicle. An unthrottled engine running at a specific speed (max torque, for example) is going to put out a specific amount of power. If this is more power than is required to maintain the desired cruise speed, the vehicle will speed up. If you want to prevent this without throttling - that is, if you want to maintain the same cruise speed without throttling, you will need to change the gear ratio. Assuming that you don't speed up, the engine will HAVE to slow down. Ray Drouillard ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] ------------------------------ Date: Sat, 1 May 1999 13:06:47 -0400 From: Raymond C Drouillard Subject: Re: Flame - Not On Fri, 30 Apr 1999 22:21:36 -0400 (EDT) William T Wilson writes: >On Fri, 30 Apr 1999, H Villemure wrote: > >> I am more of an ignoramus than most on this list- just a fresh >> mechanical engineering graduate. Could you detail what a *flathead* >> motor design consists of? > >Yeah.. the heads are flat. ;) Nothing in them but the plugs. > >During the early part of the century up through the 50's, Ford made >flathead V8s which were extremely good engines and used in a wide variety >of their cars and a number of early street rods. Not only Ford used >flathead engines though; I've got one in a '55 Jeep, which is an inline >6-cylinder. I believe that they were used with the inline 4 cylinder Jeep engines, also. > >There are some nice advantages to the flathead, not the least of which is >simplicity. There are no timing belts, chains, or any of that muck; it's >all gear driven. It is somewhat hard to get at the cams, though. Valves >are in the block right by the manifolds, so even a valve job is easy. It >is a very simple design. However, the performance is lacking compared to >OHV or OHC type engines. > No worry about the valve colliding with the piston. I imagine that if one wanted to make one today, ceramic coating could be used to combat the disadvantage of heat loss through the odd-shaped combustion chamber. Also, the more modern notion of a "pinch zone" wouldn't be too hard to impliment, and could actually take up the whole area of the piston. Ray ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] ------------------------------ Date: Sat, 1 May 1999 13:29:47 -0400 From: "Bruce Plecan" Subject: Re: NC hybrid setup/coolant blows heater core/how to avoid? What I do is, epoxy the 5/8" heater hose fitting on the manifold shut, and then cure it at 200dF. Then drill a 5/16" hole in it. That is enough for heat and defrost, here in Ohio. If you want really good control over the heater coolant, use a heater valve off a 87 Buick GN/Ttype, it's vacuum applied, On, type. If when ya do the cam, on the passenger side of the water pump is a hole in the water pump/block. Tap that out and put a 1/8 pipe plug in, it. Then drill a 1/16 or 1/8" hole in it. Also, a 1/8" hole in the thermostat. The above is just what works for me. Bruce > I know this is NC but I"ve exhausted my related Nissan/Datsun list w/ no > good info. > A few of us have sb chevy V8's and several have experienced heater core > problems d/2 higher/greater coolant flows/pressure (I don't know > specifically), they've replaced w/ brand new units and halfway thru winding > out and leaving another NSX (their ride, mine wouldn't do that;^) their > heater core will fail again. > They only discussed ways to just bypass the heater core which is simple but > I live in the often rainy pacific nw so need heat occassionally throughout > the year and would prefer some sort of pressure reducer mini-manifold but > I"m not familiar w/ what hardwar is out their or the simplest way to solve > this. I'm not sure if it's simply a matter of too much flow or pressure or > combo of both that fails them. Mine's still OK but I haven't ran it very > hard yet and want to preempt a painful heater core R&R etc. > Ross Corrigan / Vancouver, Canada ------------------------------ Date: Sat, 01 May 1999 13:43:04 -0400 From: Frederic Breitwieser Subject: 1227749 Greetings, After spending most of the morning wandering around two local junkyards, I lucked out and found two of the elusive 7749 ECMs, one passed my "power up" test, the second one didn't, and the yard I got them from said they'd exchange the bad one when they get a wrecked turbo sunbird in later today (which means middle of next week to everyone else). Also picked up a 2-bar MAP sensor using GM part numbers as a reference, for $15. It was sitting on a shelf believe it or not, so that piece is done. Coincidentally, the body harness I snagged to give my old beater truck power everything (windows, locks, cruise, digital dash) plugs right into two of the three underhood ECM harnesses with ease, and I have to verify the wiring to ensure I don't have any ground and batt leads interconnecting. At least the connectors fit... moving wires around has become quite easy after all the practice I'm getting! Sorry for the cross post... so many people have given me help and advice I wanted to make sure you all know I appreciate it !!!! Oh, and I pressure tested my homemade fuel rails this morning and they leak right through the aluminum tubing. I found that odd. I know aluminum is somewhat porous compared to other metals, but 100psi of air pressure on the end of the fuel rail, submerging it into a litter box full of water resulted in small bubbles forming on the surface of the aluminum. When the pressure is released, the bubbles appear to receed back into the aluminum. Very odd. Just thought you'd all get a kick out of it. - --- Frederic Breitwieser Xephic Technology "Leadership in IT" Bridgeport, CT 06606 Web: http://www.xephic.dynip.com Voice: (203) 372-2707 Fax: (603) 372-1147 ------------------------------ End of DIY_EFI Digest V4 #255 ***************************** 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".