DIY_EFI Digest Wednesday, June 23 1999 Volume 04 : Number 373 In this issue: server troubles A/F ratio and fuel volume Re: A/F ratio and fuel volume Re: Todd's sure fire blower sale Re: cc's of fuel to cc's of air Re: NC crank prep/lightening for a DIY'r? Re: A/F ratio and fuel volume Re: ION sense stuff Mad Max and blower drives I NEED HELP!!! Unsubscribe us please! Holley ProJection stuff 318 cam timing dilemma? GS Nationals Brain Pharte Re: cc's of fuel to cc's of air See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 22 Jun 1999 14:49:57 -0500 From: steve ravet Subject: server troubles You might have noticed the listserver sending out old posts. The machine that runs the 3 lists (diy_efi,gmecm,efi332) had a partial nervous breakdown. The problem is the volume of mail these lists stir up (10s of thousands every day). This machine also runs a "real" WWW page and email for a lab at ohio state. Needless to say we can't be causing problems for their lab. Till we work something out, I'd like everyone to be careful about what they post, especially to diy_efi. We get pretty far off topic sometimes. Rear ends, transmissions, engine building, etc. are interesting but off topic. Congratulatory, thank you, "me too", etc. posts should always be sent privately rather than to the list. The standard usenet rules work well for mailing lists also: If someone asks an off topic question, please reply privately rather to the list. If you want to know the answer too, ask the original poster to send you any replies. If you asked the question and a lot of people are interested in the answers then it might be OK to post a summary to the list, use good judgement. No flames. This isn't too much of a problem fortunately but sometimes they show up. Flames never ever serve a purpose but they do generate traffic and take up space in the archive. thanks. please resume your regularly scheduled EFI - --steve - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ Date: Tue, 22 Jun 1999 13:14:54 -0700 From: Jason_Leone@xxx.com Subject: A/F ratio and fuel volume <> Damon, This seems to simple, perhaps I'm missing something here. Stoichiometric (Lambda) is 14.7:1 air/fuel ratio. So, 1 CC of fuel to 14.7 CCs of air is stoichiometric, in theory. Just divide the air volume (of any unit) by 14.7 (of the same unit)to calculate the fuel volume needed to equal Lambda. For example, if you had a total volume of 45 CCs in the cylinder head...then 45/14.7= 3.06 CCs of fuel required for Lambda. Granted, this is just an estimate. There are a lot of other factors, such as temp, chamber geometry, injector type/placement/spray pattern, system pressure, ignition timing, and a few others. But, to answer your simple volume question...just divide by 14.7 and correct for any unit you use (metric or SAE). Good luck. Jason '93 SLC ------------------------------ Date: Tue, 22 Jun 1999 16:40:07 -0700 From: "Damon Kelley" Subject: Re: A/F ratio and fuel volume Thats what I figured but according to these calculations my engine would use the entire tank of gas in a quarter mile pass. Is the amount of fuel for the volume under compression only. I am pretty sure that wouldn't work. > > < cc's of air for stoichometric(sp?) mixture. Any useable volume units > will be sufficient. Thanks>> > > Damon, > > This seems to simple, perhaps I'm missing something here. Stoichiometric > (Lambda) is 14.7:1 air/fuel ratio. So, 1 CC of fuel to 14.7 CCs of air is > stoichiometric, in theory. Just divide the air volume (of any unit) by 14.7 (of > the same unit)to calculate the fuel volume needed to equal Lambda. For example, > if you had a total volume of 45 CCs in the cylinder head...then 45/14.7= 3.06 > CCs of fuel required for Lambda. Granted, this is just an estimate. There are a > lot of other factors, such as temp, chamber geometry, injector > type/placement/spray pattern, system pressure, ignition timing, and a few > others. But, to answer your simple volume question...just divide by 14.7 and > correct for any unit you use (metric or SAE). Good luck. > > Jason > '93 SLC > > > Damon Kelley 87 Shadow ES T1 A-520 Cold Air Induction, Bleedin' 89 Sundance N/A 89 CSX #208 26,000miles in 5 months or less 96 Sebring JXi Conv 96 CBR600F3 Soon to have cute little talon turbo ------------------------------ Date: Tue, 22 Jun 1999 16:49:07 -0400 From: "David A. Cooley" Subject: Re: Todd's sure fire blower sale At 03:00 PM 6/22/99 -0400, you wrote: > > >Good point Mike, > >May need to run some sorta alcohol or water pre injection thru the >blower in order to cool the intake charge, ey? > Actually, for the best cooling, inject the water and/or alcohol after the blower. =========================================================== 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: Tue, 22 Jun 1999 16:52:26 -0400 From: "David A. Cooley" Subject: Re: cc's of fuel to cc's of air At 03:00 PM 6/22/99 -0400, you wrote: >Does anyone have a formula for find required cc's of fuel for a given >cc's of air for stoichometric(sp?) mixture. Any useable volume units >will be sufficient. Thanks Hi Damon, Going by Mass, 14.7 grams of air are needed for 1 gram of fuel. =========================================================== 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: Tue, 22 Jun 1999 21:16:10 +1000 From: "Geoff Richards" Subject: Re: NC crank prep/lightening for a DIY'r? Ross Corrigan mailto:zxv@xxx.ca wrote Any good >before/after pics anywhere for knife edging etc? A read from the step-by-step guide to Engine Blueprinting states that *quote* To our knowledge,no-one has ever tested whether sharpening the counterweights provides any real benefits (aside from the obvious advantage of lightening the rotating assembly).On the face of it ,it seems doubtful.As any textbook on aerodynamics will point out,it is the TRAILING edge of an object not the leading edge that accounts for most of the drag.In fact,the "perfect" counterweight shape would be from an aerodynamic standpoint would be a teardrop, with a blunt leding edge and a long,tapering tail.So if you want to spend time shaping the counterweights for a racing engine,it might be wiser to concentrate on the back ends of the counterweights *end quote* I realise not everything that's printed is true,the message just jogged my memory so I thought I'd post what I'd read Leave ya to it Cheers Geoff ------------------------------ Date: Tue, 22 Jun 1999 15:55:42 -0700 From: Jason_Leone@xxx.com Subject: Re: A/F ratio and fuel volume Damon pleads: <> Damon, Okay, now I can help you better (since I know what you're trying to do). It's pretty fundamental to calculate fuel requirements. What threw me off was the mathmatical approach you had. OK, what you're trying to calculate is called B.S.F.C. (Brake Specific Fuel Consumption), in one form or another. You want to know how much fuel your 2.2L turbo engine will need @xxx.50 BSFC, while forced induction equipped engines run about .50-.60 BSFC. To run a little "rich" at first, let's assume .60 BSFC. We can always dial the fuel back later. Let's attack it from a different angle. Let's set a power output goal first, then use that as our guideline. Say, you want a healthy 300hp. Using that number, we can calculate all the fuel needs and component requirements. Let's look at the formula below: Fuel requirement (lbs/hr) = (HP * BSFC) / (# of injectors * duty cycle) Example for a 4 cyl w/ 300hp using a turbo and 80% duty cyle max: Fuel = (300 * .60) / (4 * .80) Fuel = (180) / (3.2) Fuel = 56.25 lbs/hr per injector (at that injector's rated pressure) Convert lbs/hr to CC/min by multiplying by a constant of 10.515. So, using our example: 56.25 * 10.515 = 591.46 CC/min So, each injector must flow 591.46 CCs/min to achieve 300hp @ 80% duty cycle @ the the rated pressure of the injector (usually ~43.5psi). Looks like a 600 CC/min injector will work fine. Then, you have to determine what the system pressure is, in regard to the test (rated) pressure of your injectors. If you use an adjustable FPR and set it to 43.5psi, no problem. What if the system is more or less though? Well, we need to calculate the difference in flow vs. pressure Delta. To calculate this: (new fuel pressure/old fuel pressure) =x square root of x * old flow = new flow Say you're running about 58psi, but the injectors are rated at 43.5psi. (58psi/43.5psi) = 1.33 (1.33) square rooted = 1.153 (1.153 * 591.46 CC/min) = 681.95 CC/min Hmm, now your injectors flow over 680 CC/min. Now you can downsize the injectors, reduce the system pressure, or reduce duty cycle to match your 300hp goal. We need to know how much fuel the pump can supply now. We know how much the engine needs, now we need to figure out the pump. Let's say you have an in-tank unit and it's stock. Use a graduated cylinder or a Buret to measure CCs of fuel delivered and at what pressure vs. time. I usually jumper the pump on and fill up my container for 30 seconds. Measure the amount of CCs and multiply it by two (to get CC/min delivered). Have a friend measuer the actual voltage AT THE PUMP, while you do this. You can now use some graph paper to make a linear fuel delivery vs. voltage chart. More voltage at the pump, more fuel delivery. Kenne Bell offers a device called the "Boost-a-pump" that does just that. It's an adjustable voltage regulator that's boost referenced...so more voltage gives more fuel as you come on boost. Once you have a little chart together (or maybe your factory service manual will have a chart already...Bosch equipped cars usually do), then you know how many CCs the pump can deliver @xxx. Divide that number by the number of injectors to know the theoretical flow maximum to each injector. If you know the factory pump isn't going to work from the start, simply add the sum total flow of all injectors and look for a pump that's rated in that range. Using our 43.5psi example, we know that we'll need a 225 lb/hr single pump (56.25 lb/hr per injector * 4 injectors). Convert lbs/hr to gal/hr by dividing by 6. So, 225 lbs/hr is about a 37.5 gal/hr pump (@xxx.hr to L/hr by multiplying it by 3.785. That means a 145L/hr pump @xxx. Using a little secondary pump works well too. For example, leaving the in-tank pump to feed a larger frame mounted pump is fine. By having a low pressure unit feed a high pressure...or vice-versa...even an accumulator reservoir in between the two pumps is great. Vortech makes a unit called the "T-Rex", SX makes a few pumps, Paxton makes a few, NOS does, Kinsler has a few, Bosch has millions of them that all these companies call their own..... Hope that helps. Knowing the fuel requirements will help you size everything properly. Tuning is another story. A/Fs of about 12.5-13 are common in the turbo world (while at max boost). If using auxiliary injectors to supplement factory ones...the above formulas can still help. If the software/engine management you have can't allow for large injectors...piggy back ones are your answer. I can't stand doing it that way though, I refuse to add injectors because my intake manifold isn't designed to flow fuel (one cyl runs lean, and KABOOM!). Split Second makes a good A/F meter and fine tuning unit. Haltech makes decent injector controllers, and such. FWIW, I use the Electromotive TEC II, and it's great for turbo cars. Cheers, Jason '93 SLC ------------------------------ Date: Tue, 22 Jun 1999 17:59:58 -0500 From: steve ravet Subject: Re: ION sense stuff Peter Gargano wrote: > Nic van der Walt wrote: > > > I have looked at the ion sensing stuff and I really like the idea. Has anyone > > got any more info on it? I'll build a flyback converter sometime to get > > the 400V or so bias and start logging data for analisis. Does anyone know at > > what bias voltage the plug will start sparking over? I'll want to push up the > > bias enough to get a reasonable current to measure. > > As I understand it, people have obtained reliable ION currents with sense voltages > below 100 volts. On the other hand, many people have used voltages as high as 400. > Only a simple circuit seems to be required to generate a bias voltage as there's a > lot of both negative and positive current flowing from the kVs required to strike > the plug. I'd like to see what's the simplest circuit (a cap + zener?) required to > generate a bias. At the other end, I've heard that at least 12 bits of A to D are > required to get a reliable sensed current due to the dynamic range of the signal > but this may be only required for some of the newer applications that require "curve > fitting" to do some fancy calculations. There was some discussion about voltage levels in the archive. As I recall, Saab uses 2 voltage levels, about 80 and about 400. I think the reason had to do with lower voltage levels attracting particles to the plug electrodes and cruding them up. Someone else mentioned using an A/C bias to combat the problem but I don't recall if that was tested. This is from distant memory so it may be totally wrong... Also, I moved this reply to diy_efi instead of efi332 as diy_efi is more appropriate. - --steve - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ Date: Wed, 23 Jun 1999 11:27:08 +1000 From: Wayne Blair Subject: Mad Max and blower drives The switch activated Blower on the Ford Cleveland in the XB Falcon Coupe that apperared in the Mad Max movie is a gimmick. The blower was an empty case - carb inside. Have you noticed that all the light duty blower belts are grooved to allow slip when things go hickup, the big boy stuff has teeth (no slip) and there is usually lots of work done on the front of the crank to cope with this including larger snouts and out rigger bearings. For interest the standard drive for GM blowers is a short "axle" like rod about 12 mm thick, and the blowers are run at about 200% ie less than 5000rpm max. An air box pressure of about 5-8 psi is achieved by a 420 cu blower on a 426 cu 2 stroke engine. GM 2 stroke diesel have ports in the side of the bore and exhaust valve in the head, the blower is needed to help fill the cylinder with clean air. the block of 6-71 can be used in many configurations sometimes the blowers looks like it is on the exhaust side. GM will run with out a blower - just. maybe of interest <<<<<<<<<<<<<<<< bye >>>>>>>>>>>>>>>>> wayne [Brisbane Australia] ------------------------------ Date: Mon, 21 Jun 1999 14:14:00 +1000 From: "Powerchip" Subject: I NEED HELP!!! Unsubscribe us please! hi how do i go about unsubscribing to diy efi???? It is overloading my system!!! Regards Travis Cattach Powerchip Pty Ltd sales@xxx.au - ----- Original Message ----- From: Walter Sherwin To: Sent: Monday, 21 June 1999 11:57 Subject: Re: Todd's sure fire blower sale - Fred, > > >Autorotor just came out with a new, bigger than before available screw > >supercharger--that displaces about 2 or 2.2 liters per compressor > >revolution (before the VE correction. That is as big as they go, unless > >somebody has adapted a Joy or Gardner Denver, or a Sulair screw compressor, > >or the like! > > > > > One compressor "family" @xxx.2litre per revolution max, and the other > compressor "family" @xxx. VE is shaft speed and > pressure ratio dependant, but typically spends a lot of it's time in the > high 80's. > > Of course their super-serious-competition screws are even larger. > > Walt. > > ------------------------------ Date: Tue, 22 Jun 1999 19:57:58 PDT From: Bill the arcstarter Subject: Holley ProJection stuff OK, I'm sending this to the diy_efi list and to the 2-3 people who have e-mailed me about the ProJection system. I'm not sure if this should be discussed on the diy_efi list. Can anyone comment? I'd think this stuff should be public but I don't want to dump on the list if nobody wants to hear it, etc... At any rate I think us ProJection users should at least be aware of each other, etc... I just acquired a very lightly used (99% brand new) 900cfm 4Di about 2 months ago. I had a slight problem with that unit, as some old gas had dried up and clogged one of the injectors. Nothing a good soaking in the ultrasonic tank at work wouldn't fix! :) I think the only difference between the 700 and 900 cfm unit is the size of the injectors, ie, throttle bore size is the same I think. Can anyone verify this? Primary inputs into the fuel map are engine RPM, and MAP Manifold Abs Pressure. The value extracted from this table is modified by a choke curve, accel pump function, and oxygen sensor trending (integrator). There is also an intake air temp sensor. I would expect this to enter into the equation at some point. The fuel map is 16 x 16 with 8-bit resolution of injector width (0-255). Holley gets a D- grade for not providing a theory of operations section of the manual. The manual is written just for an installer IMO. Very little description of cause and effect - just "do this, do that...". Certain wires were not even identified! Outrageous. There appear to be several "regions" of oxygen sensor integrator, as each one will take over depending on if you are at idle, light, or heavy throttle. This is not documented. Apparently the software does NOT have a one-parameter for lbs/hr of the injectors, etc. This means the basic maps provided have to be heavily tweaked depending on the injector size, etc. At least this is how I see it. Summit has new 85lb/hr injectors for the 4Di injection head for $69 or something like that. Anyway I've installed this unit on my somewhat whipped 350 chevy in my beater '84 Suburban (doubling it's value in the process). But I figured I needed a "mule" to test it out. Plus it was the biggest V8 I have in the driveway. The hardest part of the installation was the fuel system. I ended up mounting the electric pump in the front, inside the frame rail, more or less under the radiator. I used the stock fuel supply line, but plumbed a new return line (3/8 copper tubing). I hope nobody knows anything BAD about using copper tubing in a fuel system... :? Took me about three days to plan and install (to my satisfaction) the fuel system. I 'T'-ed into the "tank too full" fill tube (the hose which sprays gas on the filling nozzle when you refuel at the pumps) back near the fuel door for the return line. Couldn't use the stock fuel return line - too much back pressure (measured it). But this "T" works great! Had to use a $15 manifold adaptor to convert from spread to square bore. Not sure what effect this would have on overall performance. The other annoying thing was the O2 sensor. I decided to remove the driver's side manifold, and drill/tap for the O2 sensor. 18mmx1.50 :) Not too hard and made for a neat installation - as the O2 sensor sticks out of the side of the manifold. Sure beats trying to mig on a O2 bung while lying on my back under the truck... I'm not using the spark advance or knock sense since I don't have the proper components. Yet. Anyway - I'm still fine-honing the fuel map for the recommended -10 to -20% on the oxy comp. Usually I do this via Hondo logging sessions, driving at different rates, foot on the brake, up/down hills etc. I'd say the Hondo program is Mandatory for getting a nice final map - not sure how it'd be done w/o either hondo or a dyno! :) The minimum injection duration (1700 us supposedly) is too long for a clean burn at no-load speeds>1500 rpm. This includes revving in the driveway, or rolling downhill, etc. Excessive hydrocarbons are produced (I can smell them). I haven't fooled with the fuel pressure yet - that might fix this but would require more map modifications too. The logic used for the O2 compensation voltages is rather odd and kludgy IMO. There is an undefined "operation mode" variable, from 0 to 4 or something... I'd be happier if the system contained an array of integrators parallel with the main fuel map, like the GM ECU's do... The cold start "choke" system works just fine. I've seen a few odd things with this system. On three occasions, the O2 was reading rich, but the O2 compensator was INCREASING, adding injector duration, until the motor actually died from excessive fuel. On all three occasions it was at idle when this happened. This throttle body will flow a LOT of air! At 4000 rpm I get 99% of full atmospheric pressure on the MAP at under 30 % of full throttle opening. This makes for a very sensitive accelerator. I need to re-linkage this to make it less sensitive. Once for whatever reason it wasn't reading the MAP. That made for some interesting malfunctions... Power down/up and all was well. So far I've been impressed with how well it works. I get MUCH more power than my old Roch. Quadrajunk unit (no offense but I hate that old thing). 'Course some of that is perception - due to the fast-acting throttle action, etc. I haven't been driving it in a sane way to see if gas mileage has increased. I would suspect it has. My idle is rather rough with this unit. Not sure if that is because the host engine is sort of tired, or since this injection head is rated 900 cfm (ie - too big) or ?? something else... The idle is very smooth if I turn off the oxygen sensor and just run raw uncompensated fuel map at about 10% rich... Not sure how to interpret that. Plugs, wires, coil, cap etc are new. Next on the agenda will be cam, intake, exh, and head refreshening. Then we'll really be rolling! Wonder if the transmission will take it? (700R4) Comments encouraged. - -Bill _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com ------------------------------ Date: Tue, 22 Jun 1999 20:34:14 PDT From: Bill the arcstarter Subject: 318 cam timing dilemma? Guys, I was hoping someone could give me some advice regarding degreeing in a cam in my 318 (Dodge pickup)... The problem started about three years ago when I was young and stupid I more or less just slapped in some sort of "tow truck cam" with a stock emissions-type timing chainset. I never did get much of a performance boost out of it... Not being wise in the ways of the masters - neither did I acquire nor retain the datasheet for said bumpstick. So I don't know where (degreewise) it should be positioned. So the other day I decide to slap the dial indicator and degree wheel on it to see what I have. I have hydraulic lifters, so I removed the rocker rail and arms prior to the measurements. Here are my measurements: Intake opens 0.050 at 12 ATDC Intake lift is approx 0.277 at the cam Intake closed to 0.050 at 40 ABDC Exh opens 0.050 at 42 BBDC Exh lift is approx 0.288 at the cam Exh closes to 0.050 at 68 ABDC Computed quantites being: Intake duration at 0.050 is 208 degrees Exhaust duration at 0.050 is 220 degrees Intake centerline is at 116 ATDC Ok - so I get out the old Edelbrock book to look through Chrysler cams to see what I have, or at least something close. Note that my cam is NOT an Edelbrock cam so we're talking "close match" here. Based upon intake duration it looks like this cam would be somewhere between a performer and performer-rpm. The problem is that Edelbrock locates their intake centerline at about 106 degrees ATDC. Compared to my measured/computed 116 degrees - looks like my cam might be somewhat retarded to the tune of about 8 or 10 degrees... No Edelbrock 318 cam of any sort uses an intake centerline more than a degree away from 106 ATDC... Likewise no listed cam has a intake open at 0.050 at such a strange location as what I measured. Does this make sense? The motor runs ok, idles ok, but has minimal low end (<1300 rpm) power. It does OK at the higher rpms (somewhat bad gas mileage still), but I need more low end since I'm turning a manual gearbox, etc... No - it didn't skip a tooth on the chain. The dots line up just fine as they should. Any help would be greatly appreciated. I will be picking up my triple-keyway timing chain set tomorrow - and I intend to advance this cam and remeasure. - -Bill (trying to save a 318 instead of killing it like some folk on this list! :) ) _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com ------------------------------ Date: Tue, 22 Jun 1999 23:05:21 -0500 From: DC Smith Subject: GS Nationals Just a little FYI.. The GS Club of America is having it's "Nationals" in Columbus Ohio this week. It runs June 21-26 At National trails raceway. A full WEEK of drag racing SFI'd turbo cars, and a lot of old GS Buicks. I realize this is not a lot of EFI content, but anyone serious about cars and going fast should try and make it a point to try and attend. I feel friday will be the best day to see the inner workings of these beasts, since that's the day of the car show. Everyone will be sitting with their hoods up. If anyone makes it there, be sure to say hi.. I'll be in the black Regal. just kidding.. there'll prolly be ~2,000 black Regals there. :^) Look for Missouri tag ZR WHAT, the number on my window will be 1459. Hope to see ya there! *********************************************************************** Dan Smith 84 Regal 12.13@112 GSCA# 1459 St.Charles, Missouri mailto:dcsmith@xxx.net http://www.tetranet.net/users/morepoweral *********************************************************************** ------------------------------ Date: Wed, 23 Jun 1999 04:49:55 GMT From: bob@xxx.com (Robert Harris) Subject: Brain Pharte Once upon a time, back when Moby Dick was a minnow, I used to work at a chemical plant. We used strain cells about 2" square or less to weigh bins contained 50,000 lbs of product or more very accurately and this was well before digital enlightenment by Bill Gates. Many cylinder temperature gauges are simply sandwiched between plug and head. Connect the dots. Sandwich a strain gauge between the head and the plug in a washer. Shouldn't I be able to read the pressure just like I read the weight. The bin probably distorted the gauge less than the slack between threads would allow the plug to move. Torque the plug down till it "reads" say 2000 psi. Then as the cylinder pressure builds, the pressure gets "less" as the plug moves away from the head. Invert the readings and voila - non invasive combustion pressure sensing. Might also be able to use a strain gage between a motor mount and get instant torque per degree of rotation. Might be useful to plot peak torque vs combustion pressure and analyze. Just a brain pharte to get some thinking going on how to get a sensor that engine management could use. ------------------------------ Date: Wed, 23 Jun 1999 00:03:46 -0700 (PDT) From: Mark Wilcutts Subject: Re: cc's of fuel to cc's of air What temp and pressure are you looking at? stoichiometric mixture is 14.2-15.2 kg air per kg fuel, depending on composition. density of air is 1.20 kg/m^3 at 20 deg.C and atmospheric pressure. density of gas is between 732 and 752 kg/m^3, depending on season and grade, at 60 deg. F. > Date: Tue, 22 Jun 1999 11:32:50 -0700 > From: "Damon Kelley" > Subject: cc's of fuel to cc's of air > >Does anyone have a formula for find required cc's of fuel for a given >cc's of air for stoichometric(sp?) mixture. Any useable volume units >will be sufficient. Thanks ------------------------------ End of DIY_EFI Digest V4 #373 ***************************** 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".