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 Hi there, I live in Ca and I suppose you live around my neck of the
 woods, I am up in Sonora, closest airport is Columbia.

 I read your article on the Fuel Injection installation on your rotary
 engine website with big interest.

 I have a VariEze, that I just love, it is very efficient.

 I understand that Klaus S, have a similiar system for sale.

 I want however a sequential Fuel injection system, and he claims that
 his system is not sequential.

 I don't know about rotarys, but in piston engines (I have an O-200), the
 efficiancy will go up if you use a sequential FI system.

 Soooo...looking at your plans on how to build one, I looked and looked
 and finally I decided that the system you are proposing is a very good
 system, and it can be made sequential.

 The key question here is basically, the function of the 555 chip.

 In order for this to work, the 555 chip has to open and close ONES per
 command (Per trigger) .

 I looked at the system, and can conclude that all the indication systems
 can be common, intake pressure probe, etc.

 The only difference actually is that there has to be four triggers,
 instead of one. One for each cylinder, (I know, some more sophisticated
 systems just have one camshaft sensor, but that means I have to ad a
 timer clock, and it will start to be complicated in that way, I want to
 keep it as simple as possible, and have four trigger points is not that
 hard.

 The whole question that will make or fail this project is the way the
 TLC 555 chip works.

 Can you please tell me how it behave once it is triggered, will it start
 pulsing, for a while, (on and off) according to the internal clock, and
 stop after a while...or will the TLC 555 shoot ONCE, after each time it
 is triggered?

 Reason I am asking is that a batch fired system , doesnt really matter
 that much, the injector can sit and pulse, , and shoot fuel per the
 pulses it recieves, no matter if the intake valve is open or not.

 That, ( in a piston engine....and I assume also in a Rotary engine) will
 lower the efficiency of the engine, as fuel will be delivered
 differently for each stroke.

 Some intake strokes, will get a little bit, and when the valve closes,
 the injector squirts a bit more, and when the valve opens next time, it
 squirts again, and now the engine is sucking in the previous fuel, plus
 the fuel it is currently delivering.

 So, some strokes will run lean, some is just right, and some is rich.

 Therefore, if I want to build a FI system I want to build the most
 efficient I can do ( Direct fuel injection will be a bit too much
 problem to handle though, so on that I will pass) , and the best I can
 build would be a sequential FI system.

 We will run into another problem here, I will need bigger injectors, as
 a batch fired system have no time restriction on its fuel delivery, ,
 but a sequential system has to deliver all the needed fuel in a quarter
 of the time. ( Intake stroke, or the time when the intake valve is
 open.....it actually has a little bit shorter time to accomplish this
 in, as you can not start spraying in fuel, just as the intake valve
 opens, you have still pressure in the cylinder, and the full effect of
 the overlap has not starting to take effect just yet.)

 So I have about one fifth of the time to deliver allo the fuel I need.

 Now, as I understand, the size of the injectors doesnt really matter,
 this system can handle it all pretty good, and actually run the
 injectors straight.

 You seem to have already been doing this a little bit, and maybe can
 come up with some general advice on this, but my main question is if the
 TLC 555 chip will trigger once and give one pulse, or if it will
 continue to pulse, after each time it is triggered?

 Also, I live up in the boondocks, and the only thing around here is
 Radio Shack, and they don't have much, are there a good electronic
 retailer around where I can stock up on all the things needed around
 here, ( lets say Stockton, Manteca, Modesto or thereabout)

 I saw from the photos on the website, that you have some goodies, and
 have made a really good set up, circuit boards, good fitting heat sinks,
 and everything, did you do them yourself, or do you have a bunch
 produced, ( for sale) .

 I would appreciate to hear from you, and kick some ideas with you.

 Roger Isaksson

 http://www.rotaryeng.net/simple-cheap-555.html

 I am not sure our approach will work as we have not tested it yet.
 At 7500 RPM one only has about 8 milliseconds to work with for one
 RPM. We are about to test it in the next six months unless something
 more important comes up. I am am not sure how Klaus is doing it.

 DigiKey or Mouser both give fast service on mail orders.
 http://search.digikey.com <http://search.digikey.com/
 <http://search.digikey.com/
 <http://search.digikey.com/
 <http://search.digikey.com/
 <http://search.digikey.com/
 <http://search.digikey.com/

 We also don't have any parts for sale just yet but you are welcome
 to use our art work to build your own PC boards.

 Frankly I am not sure timed is the way to go. I am about to instrument
 and test another EFI system already sold for use in rotary aircraft
 engines and will know more about that shortly.
 http://www.hytekautomation.ca/

 We will record when the fuel is injected into the manifold relative
 to the e-shaft angle and of course how long the injector is open.
 Manifold pressure will be recorded in several different places
 to check for aerodynamic differences. All of this will be done over
 a range of RPM's using an actual propeller for a load at a rate of
 1000 measurements per second.

 Stay tuned.

 Paul Lamar

 Hi there Roger here again,

 Have been studying up a bit better on the rotary engine, whoops, didn't
 work the way I thought, oh well.... I told you I was a bit weak on it.

 Well I am in this for the FI and the ignition systems, they look great.

 Fourstrokes are my forte, but hey I am eager to learn.

 Ok back to the FI and so on....the FI system I got fired up about, do I
 understand it right that no one have tested it, the one with a 555
 chip???

 Hm...also, I saw another cheapy made and great looking, very simple
 ignition system, and wonder, ...do you think that the diodes can
 light up
 the FI system as well as the magnetic trigger can?

 Been thinking of what bugs most people, when it comes to engines, that
 is ...to be able to start them up.

 So I'm thinking, like in a fourstroke, or perhaps also in the start up
 sequence of a rotary, lets say that under 100 RPM the system would go
 over to a start mode, meaning, in the case of a four stroker, ( or
 perhaps also a Rotary, realize now that I don't know half as much about
 those than I thought, so I better hold my horses when it comes to
 those)...so ok, lets talk fourstroke.

 If in the starting moment, the ignition system would fire every minute
 from 12 o clock to 4 o clock, giving the ignition system plenty of
 chances to arrange a meeting between one oxygen atom ( comes in pairs)
 and a fuel molecule, to have a happy marriage.

 Lets say that in the cockpit there would be a three way switch, off ,
 start and run.

 Most probably there would be a second, set of ignition system, most
 probably a set of Slick or Bendix magnetos sitting there, but they would
 in the firing sequence fire with the clicker, and that is pretty much on
 the 12 o clock position, so the magneto could be left alone, and on ON.

 The electronic ignition would be set to START.

 Ok there would be a disc, with holes set on two race tracks, and each
 race track would have it's own LED, and sensor, the switch in the
 cockpit would shift between the two LED's and trigger sensor.

 The first start position, would have a disc with a lot of holes in it,
 that would make the trigger fire from 12 o clock to 4 o clock several
 times, and now you hand prop the engine, and make the spark plugs
 fire in
 the start mode.

 While the engine is hand propped, the ignition will be served from both
 the magneto independently, and from the electronic ignition that would
 trigger the spark plug very often,from 12 o clock until it reaches the 4
 o clock position.

 Once the engine starts, the magneto will automatically start firing in
 advance, and the electronic ignition would not do anything else than
 just firing away into an already burning combustion, until the pilot
 have walked back to the cockpit and switched the electronic ignition
 from START to RUN, where the electronic ignition now will fire in unison
 with the magneto.

 One more thing and this will be as good as it will get, able to advance
 the ignition. By a simple mechanical device run by a perhaps small
 stepper motor, the C clip arrangement of the Diode and trigger, can be
 rotated around the periphery of the rotating timing wheel, and the
 setting controlled by the pilot.

 I have some questions.

 - The circuit board I can see in the pictures for the 555 system, did
 you do them yourself, or did you order them somewhere...just wonder how
 I can get my hands on some of them.

 - What pressure sensor are you using for the FI system, it didn't became
 fully clear of the description of those, there was a lot of serial
 numbers on chips, and other electronic components, so maybe I missed it,
 but I am thinking that maybe it wasn't there... could not find it.

 - The adjustable resistor, that will adjust the timing of the FI systems
 firing period and are suppose to sit in the cockpit, is a bit unclear to
 me. Resistance is measured over two points, but the resistor described
 had three legs, and I wonder how the internals of that variable resistor
 is wired?

 Preciate it, and Happy New Year

 Roger Isaksson

 Your starting scheme can be made to work as the photo interrupter
 circuit has a lot flexibility.

 We use about 50 psi so it uses a stock automotive EFI pump and
 regulator.

 I get my circuit boards from http://www.expresspcb.com/
 They have free PC board design software. If you download
 it I can send you the files I have so far and you can buy
 boards from them. Or you can use them as a starting point and
 change them to suite yourself. Here are a couple of jpg of boards
 that I have done. The software is easy to learn.

 The pressure sensor is a $10 Freescale part from Digikey.
 The mpx 4250 data sheet is attached.

 The leaning pot on the dash board is an off the shelf variable
 resister. Try 10K for a wide range of mixtures. It does not change
 the timing but only the pulse width. Narrow for lean wide for rich.
 I modified the ske to show how it works.

 Also an ABS sensor from Pep Boys is cheaper than the Mazda crank
 angle sensor. It works the same.

 If you are using this on a piston engine you will have to sense
 the cam shaft position as it rotates half as fast as the crankshaft.
 a timed one rotor squirts every rotation while a timed one cylinder
 piston
 engine squirts every other rotation so you need to know when
 the piston engine is on the intake stroke. Probably the best
 place to do that is on the mag drive gear. Probably one reason
 Klause does not use a timed injection :) This 555 system does
 not need to be timed. You could let it squirt on either the intake
 stroke or the combustion stroke as the intake valve is closed.
 Another way of doing it is a capacitive spring loaded clamp on an
 ignition wire to sens when the engine is on the combustion stroke.
 You will be on the bleeding edge when you do that as I have
 never used that trick :)

 Paul Lamar

 -- Paul,

 Did study the explanation on the leaning system,, clear as a
 crystal ball, ok got it...thanks.

 Are gathering all the info for ordering all the needed stuff.

 Now the billion Dollar question...

 Here is this pilot sitting in his cockpit and are adjusting the flow to
 the engine...ok good enough,.... but how would he know when he is in
 stochastic range, lean or fat?

 There is simpler systems for cars, where you can just install an extra
 oxygen sensor, and there is a fuel/air mix gauge you can read off, but
 as most aviation based fuel, have quite a bit of lead in it, and with
 leaded fuel, the oxygen sensor will not be long lived, and will start
 showing erroneous values pretty quick.

 If it would not be for that darn lead, the oxygen sensor is probably one
 of the most gallant and excellent solutions, the oxygen sensor, is not a
 switch but a galvanic element, and have very fast reaction time, and it
 reads very precise.

 And it is so darn simple that it is almost ridiculous, an oxygen sensor,
 a needle gauge  up front, and a circuit going through it, that's
 all....hmmm....

 Damn lead.

 Wonder if there is a way around it????

 I am aware of all these "big" solutions that can read air /fuel ratios,
 with throttle position sensor, mass airflow meter, computer programmed,
 and the whole jadijada, but not the simple elegant solution.

 If the pilot can not set his fuel mix to the value he wants, he just
 wouldn't know where he is on the fuel map, he can sit and turn that
 adjustment knob as much as he wishes, but he will never know what he
 will be feeding the engine. All he would know is turning to the left
 would mean leaner, and to the right would mean richer, but he wouldn't
 know, other than getting indications from indirect measurements, like
 cyl head temp, exhaust temp, or listening for rough running etc.

 Compared with a carburetor, a FI system is a precision instrument, but
 he would be like a guy sitting with a precision sniper rifle, with a
 high magnification scope, and shooting........ blindfolded........ all
 he can do is to aim in the general direction, and cause a bang.

 Any thoughts in that direction?

 Roger Isaksson

 Pilots are trained to adjust the mixture according to Exhaust Gas
 Temperature.

 When you start the engine it is rich and the EGT is cool.
 You take off full rich at full power. When you reach cruising altitude
 and want to minimize fuel burn you lean the engine and watch the EGT
 rise. You keep leaning and the EGT reaches a peak (stochastic) and
 starts going down. When it reachs about 50 degree F lean of peak the
 fuel burn or BSFC is the lowest.

 The Holy Grail of EFI systems is to do this automatically. It is
 called auto lean. It was available on turbo compound CW R3350
 air liner recips back in the 1950's. Mistral also offered it
 on the rotary before they went bankrupt.

 Unfortunately Tracy's system does not do this and that is one reason
 it is so hard to tune. Tracy makes a big deal out of tuning the engine
 in the air without a lap top computer in the cockpit but then he
 also uses
 a crude and cheap manifold pressure sensor as the main indicator of
 the power required. The system cost over $1000 dollars so IMHO he could
 damn well include a mass air flow sensor since they are universally
 included in every car EFI on the planet. The manifold pressure sensor
 sampled by a computer is a one millisecond snap shot of what is
 going one
 in the turbulent intake manifold at that particular time and that
 specific place in the manifold.

 So far every installation is different as every side port manifold is
 home made. Consequently the mixture map is all over the playing field.
 In the 555 system the pressure sensor does not give us a snapshot
 but automatically averages the manifold pressure readings. A simple
 capacitor can and will improve the average in the 555 system.

 Paul Lamar

 -------------------------------------------------------------------

 thanks read the diagrams of leaning/riching  and the effects of
 temperature , power and economy.

 Yes, you are right ....a mass flow sensor would do a lot of good, but
 ...again, if the exact air/fuel  ratio is known, ...I really don't mind
 setting the mix myself, even if it can be done automatically.

 Dont get me wrong, ...if there is a way to have the mix automatically
 set...I'll take it,....as long as I can, on my own determination bypass
 the auto, and put it in a manual mode, and set it whenever I choose to
 do so....that is, if I could read off a display that would tell me in
 fractions the fuel /air ratio.

 Why a mass flow sensor is not in the 555 system...beats me...when
 thinking of it, ....if a mass flow sensor will determine an exact way to
 distribute fuel, why not substitute the pressure sensor with a mass flow
 sensor.

 I know that the pressure sensor is linear and the mass air flow sensor
 is not, but if one way to measure how much fuel is needed, and it
 happens to be not linear...so what. It is the true ratio, so why not.

 What would happen if a mass flow sensor was to substitute the pressure
 sensor in the 555 system?...I mean both the pressure sensor, and the
 mass flow indicator communicates to the rest of the electronics in the
 same way.

 All it is, and both are doing the same thing, either there is a voltage
 or a resistance that goes up or down, ( for the mass airflow sensor, a
 heated wire is used, and that is resistance that changes)

 All we are doing is to look at the same electronic signals, in an effort
 to determine how much fuel we want to squirt in. One measures pressure,
 and takes no consideration of density, , while the other measure the
 true density of the air, and thus will give a true representation of the
 column of air in the intake .

 I mean, what we want is, to give a specific amount of fuel to a specific
 amount of air mass,  what measures that better than a mass air flow
 sensor,... so what if it is not linear, let the FI follow the non linear
 curve. If an instrument can not measure the mass and flow, then it is
 not an mass /flow meter, and I am sure that there are better or worse
 mass air flow meters.

 It might take some research to get a true air flow meter, or find one
 that will actually do the job, because I have a feeling that what many
 call an air flow meter, is only a partial instrument, that will work for
 a specific FI system where there is about a hundred other sensors
 involved, but in a stand alone air flow measurement against tuned
 laboratory equipment, they will do either a mediocre or poor job.

 I have a feeling that this is where the "non linear" is emanating from,
 because if it can measure air. and mass, it should not have a limitation
 to it, either it can do it or it can't....."well it can measure mass,
 and flow...but not too fast flowing mass" ...  c'mon, don't call that a
 mass flow meter if it cant do what it is suppose to do.

 A true airflow meter, has to accurately measure the actual mass and
 actual flow of the air, if that quantity is known, that's all we really
 need in order to determine the exact fuel delivery.

 It will automatically adjust for barometric pressure, this is the
 automatic system.

 I would say substitute the pressure sensor with a mass airflow sensor
 and this system is licked.

 There are different types of sensors, some have a hot wire only, and
 that's it, some have a hot wire in a little pocket, some have a hot wire
 and a flap that moves and measure the flow, and density at the same
 time, ...VW had one for years that was very reliable, it looked like a
 pressure cockers lid, and when the intake started to suck in, the whole
 lid fell down in a recession, on an arm that held the lid from the
 top......either way, I dont know what is the best, as it seems like some
 have a partial function, hot wire only, while some have the whole array
 if measurements, , hot wire ( perhaps pressure also), and flow, with a
 vane, lid or flap. Probably the one that measure the whole hulabaloo is
 the best.

 What if the adjustment knob in the leaning/riching of the FI system had
 a set point on the knob, that could be felt, like a zero point, at that
 point the system would be calibrated to be optimal. When the turning
 knob would reach the middle position a distict "hold" would be felt in
 the knob. That could be a value that is pre determined...lets say ( out
 of the hat) 5000 Ohm or so, anything less will richen,. anything more
 will lean, but always at the "hold" point, there is a neutral spot,
 where the pilot leaves the FI for absolute neutral and automatic
 setting.

 To fine tune that neutral spot where the adjustment knob have a "hold"
 pattern, an inline additional adjustable resistor can be attached, ( you
 know, one of those that you have to set with a very small screw driver,
 that you have to reach into a hole somewhere), and when the FI system is
 at neutral, and the spot is adjusted to the "hold" point on the
 adjustment knob...you're done.

 For fun flying, or going for the hundred Dollar burger, or jumping
 around over the weekend, I would probably not even touch the FI if it is
 self adjusting, but if I would go on a long cruise, I would probably
 be very interesting in setting the FI according to my own wishes.

 There is a name that keeps popping up, Tracy, and it has something to do
 with either this 555 FI system or another system of some sort....in what
 way is this man involved with the FI system?

 Is he the guy behind the drawing schematics of the 555 system?
 Roger I.


 Tracy makes an EFI system for aircraft rotaries.
 AKA Real World Solutions.

 I did the schematics on the 555 systems.
 My early version used the mass airflow sensor but I found
 out they were nonlinear. The 555 system requires a linear
 sensor (I think) where power is directly proportional to intake
 manifold pressure. So I switched back to the manifold pressure
 sensor to keep things cheap and simple.

 One can always make a computer controlled EFI system. The Megasquirt
 is a good example of a low cost public domain system.

 I would appreciate some independent experimentation on the 555 system
 as I have my plate full right at the moment.

 I have one RX8 engine test stand that I can try it on. Right at the
 moment I am dealing with some RX8 coil issues trying to get
 it up and running. It has one of Tracy EFI systems so we will do
 a bit of reverse engineering using a data acq system to measure
 such things as coil dwell time and manifold pressure tap locations.

 My friends at Mazdatrix are telling me they are replacing the RX8
 coils with LS2 GM/Denso truck coils with heat sinks left and right :)

 Paul Lamar



 Roger, While you are kicking ideas around I have some suggestions
 learned from a few weeks of Internet searching. I have selected a ford
 mass air flow sensor which is a 2 wire sensor (one heated one not) and
 is compensated for humidity and temperature giving an output of 0 to 5
 volts. I chose a 5 liter mustang 90MM version with a die cast aluminum
 body and have a late model version with ABS housing as an alternative.
 For input into a computer chip if the voltage is converted to digital
 then cubed plus a fixed number it is extremely close to linear over more
 than the flow range  used by a rotary engine.


 Second discovery is the
 Ford EEC series of computer. The earliest were speed density, not the
 best choice. The rest are all mass air flow since 1987. The EEC-IV can
 be reprogrammed by installing a chip on the test port which
 overrides the
 internal maps. The EEC-V is reprogrammed  by reflashing the memory maps.

 The EEC computers are used in racing and that includes some F! engines,
 formula ford and drag racing. No other OEM computers are this widely
 applied. The EEC has two methods of fuel management either by mapping
 tables which are used when not at wide open throttle and include the
 oxygen sensor input as feedback in closed loop operation. The tables are
 in a matrix with each group of inputs outputting a value to a higher
 level map. When the wide open throttle contact is closed the system
 ignores all tables and calculates the required fuel only requiring the
 mass air flow sensor and if one is present a manifold absolute sensor
 and  a barometric pressure sensor. For our uses on wide open throttle
 mode an adjustment in the 0-5 volt MAF  output can alter mixture.

  I paid $27 for the MAF sensor and $41 for an EEC-V  from an F250
 truck on E-Bay.  For this same test engine I will be using the EDIS
 ignition also from Ford at a fixed advance as a stand alone system. The
 truck EEC-V was chosen for the eight sequential injector outputs which
 is required on a four rotor Mazda. The four cylinder computers are
 better
 suited for a two rotor.

 There are at least two rotary engine aircraft using the stock
 RX-7 engine computer. I discounted these solely on the basis of cost.
 They were all more than $300 at salvage yards and I would have required
 two of them for a four rotor. I bought three RX-8 engines and none of
 them came with the computer and the wiring harness was cut off at the
 connectors. The harness is going for $180  which is also discounted on
 the basis of price.

 I drive a truck I bought new in 1987 which is not garage kept and
 have never  had any issues with the engine control systems. I have also
 had two engine failures the same month renting certified aircraft. I am
 therefore more comfortable with a simple, smooth running robust  rotary
 core engine with automotive systems reliability for control.

 george grimes

 George,

 You are touching on a subject that is all to common in the aircraft
 community.

 Why is your 1987 outside kept truck reliable, when the ...several times
 more expensive aircraft is very maintenance heavy, and have fuel,
 ignition and mechanical related failures more often than then anyone
 like to.

 This is an issue I debated on another forum not too long ago, and I
 think it is mainly from many aircraft owners non understanding of how
 things deteriorate.

 An engine that is run often, like your 1987 truck, will always be coated
 with oil, but I am sure you have gone down the line of aircrafts. many
 parked outside and I am sure you as well as I, and all of us, have seen
 aircrafts that have been parked at the same spot for months, and never
 moved.

 None of them are pickled, at the very best there is a cover over the
 cabin glass, but not over the engine, and they sit there, sit and sit
 and sit.

 Once in a blue moon the owner comes out and start the aircraft and go
 around the pattern.

 Every time he starts that engine it is a demolition derby going on
 inside. There is absolutely no oil , nothing what so ever in the engine,
 everything has gone to the bottom long time ago, and as any four stroke
 can not have any propeller position ( 4 cyl and up) where all the valves
 are closed, you can bet on rust in the bore, and valves as well.

 The aircraft has been sitting through a couple of three days rain
 storms, and in between we have the fog.

 The exhaust is very simple and straight compared with cars, and can
 almost be considered a straight exhaust, ( as many in the experimental
 field have) , and internal weather systems WILL develop inside that
 engine, bringing moist to any and all exposed part.

 At least by doing a semi pickled engine, it would protect the engine for
 a long time, simple things, like getting a spray can of engine fogger,
 turn on the starter, ignition off, and spray into the intake for a
 couple of revolutions. That will leave the engine with oil that is
 coated, that will not leave the cylinders or valves, it will stick
 there, and sit and protect the engine.

 There is a lot of engine oil fogger products both in marine and car
 parts stores.

 It is funny, in the marine community this is clear as a crystal ball,
 while the same practice in the flying community, it is clear as mud.

 A simple made plug, into the exhaust pipe will do wonders, and a cover
 that will fit tight over the intake will do the same wonders.

 The majority of airplane engines does never reach the stated overhaul
 hours, before it needs to be overhauled again, while engines sitting in
 trainers, is known to go well beyond 3000 hours, and still run strong.

 If you KNOW, you will not run your airplane engine in three, four ( at
 most five)  days or more , spray it, and plug the exhaust, and intake,
 if stored in a non heated steel walled building , it gives only marginal
 protection,  use the same routine.

 I don't care if it is a piston engine, rotary engine, steam engine, or
 warp drive engine, that is about the time limit you have, three,
 four,.... five days at most, after that time, you have a dry engine, and
 then you are at risk.

 I used to say, and still make that statement...if it ever rains at your
 location, ever, do it.

 Ok leaving that and back to FI systems,

 George, You seem to have ventured into the Ford systems, and have luck
 with it, and I can see from what you are saying that the Ford system
 have probably the most versatile options, suitable for a big range of
 options.

 I will keep that as an option, ( I really will, I will pursue the Ford
 idea based on your description) while looking for a suitable FI system.

 I stumbled on the 555 system, and had an idea that it would be a solder
 together type thing, but realize now that this is highly experimental.

 I don't mind to experiment, but I rather have something that I can
 venture straight into, and I am feeling more and more that the 555
 system still needs development.

 I therefore pose a question to the whole rotary community ( or others)
 that have seen the 555 system.

 Are there any workable 555 systems out there, based on the description
 from the rotary website, that is working, and functioning?

 Similar systems work, we know that, Klaus Saviers system works wonders,
 and it could be bought, so could a couple of other systems, in kit form,
 but they are developed to a point where they will work.

 I really like the idea with low Amp draw , no computer, and simplicity
 of the 555 system, and very low cost,  thats a real winner in my
 opinion. The system have all the attributes of a winner, but I start to
 hesitate if I need to be a developer also, ...I can do it to some
 extent, and probably have to, because whatever I get,  it has to be
 tuned to my specific application, but are afraid of being drawn to heavy
 into the basic development loop, ....I just want an FI system, thats
 all.

 So, are there any 555 systems up and running now?

 Roger Isaksson


 http://www.team-bhp.com/forum/motorbikes/4615-fuel-injection-india-bikes.html



 However I am a bit more optimistic because a
 fuel injection system is rather simple. A 555 CMOS version is a
 miniature
 fuel injection system in a one dollar 8 pin IC chip. One pin is RPM
 input another zero to five volts input for engine load and a
 variable pulse width comes out another pin for the fuel injector. I
 have enough experience designing computers with IC circuits dating
 back to 1975 so I know it will work.
 Prior to that I was building radio control model airplanes (with tubes)
 as a teenager in the early 1950's. Read the "Who is Paul Lamar"
 section on my web site to see what I have done over the years.
 http://www.rotaryeng.net/who.html

 BTW I learned to fly Cubs and Champs at age 14 in exchange for
 washing airplanes.

 If you build a 555 system I have time to help by email.


 Paul Lamar


Roger,Choosing sequential injectors doesn't have to be
difficult. First method is to calculate size. Determine cubic feet of
air pumped through the engine at maximum RPM at sea level. Use air
density to convert to pounds of air. Devide by air/fuel ratio desired
such as 14 to 1 to get pounds of fuel per hour. For constant flow that
is the injector rate. For sequential sizing  devide 360 degrees by how
many degrees of crank rotation you have to inject the fuel  and multiply
the result times the full flow rate. You can use multiple injectors per
rotor (two is common) which allows the use of smaller injectors and
opens the possibility of staging the injectors from using one to useing
both determined by required pulse width.

  As a ball park number choose any four stroke with twice the CFM
as your rotary engine both at maximum rated RPM. Then go to a flow chart
or even e-bay to see what size injectors your selected engine is useing
and what fuel pressure it is useing. If your calculated size is more
than 10 percent different check your math and possibly analyze a
different sample engine.

PAUL,IF WE LET SOME OF THESE MESSAGES RUN LONG IS IT POSSIBLE THAT
BY ROTE LEARNING WE COULD EDUCATE THE NSA ANALYSISTS ABOUT THE BENEFITS
OF ROTARY ENGINES AS THEY REREAD THE POSTS. CAN WE LET THEM SUSCRIBE TO
THE NEWSLETTER SINCE THEY READ A LOT ABOUT VARIED SUBJECTS THEY MAY HAVE
SEEN SOMETHING PERTINANT WE HAVENT RUN ACROSS.  HAPPY NEW YEAR
NSA APRIL FOOLS NSA

george grimes

They read every message as we have over seas subscribers.
I am absolutely sure by now we have one or two maybe more
rotary engine experts working at the NSA and probably making
over $100,000 a year. If some of you are out of work and
can pass a security check for a top secret clearance
I suggest you apply at the NSA :)

Paul Lamar

an eazy way to size injectors
http://www.rceng.com/technical.aspx#Fuel_Injector_Worksheet_


chris smale