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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/

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

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Paul,

Ignition triggered FI,, well ...dunno about that, it would work as long
as there is only one spark per second revolution, but many systems
nowadays are using waste spark systems.

You can simplify an ignition system with half by doing that, but that
assumes you have cylinders that are opposed in its pump action of a true
360 degree.

it will work for a one cylinder engine, two cylinder, four and
eigh...and so on , if two of the cylinders reaches intake/exhaust and
ignition phase respectively at the same time.

A one cylinder would spark, burn, do the exhaust , and while it is doing
it's exhaust stroke, just at the top, another waste spark is fired,
 it wont ignite anything as it is just firing into burned gas,
..well, it shuffle out all the bad gas, and takes in a fresh charge,
and compresses it, and just before TDC ( depending on the timing set)
 another spark fires, that this time will fire up the combustion
charge.....and so on.

If you have a nother cylinder that goes in pair, but is on the opposite
side of the work stroke, you can trigger the two coils with the same
trigger to make it more simple....Like an opposed two cylinder
engine, or an opposed or in line four cylinder engine, or finding
the two cylinders that works on opposite stroke in a six or eight cylinder
engine for example.

The simplicity in this is that you can have a crankshaft sensor, that
will feel each rotation, and thus you are able to put it on any rotating
mass of convenience on the engine.

You can not steer a sequiental FI with one of those, you need to
find a distributor driven system, where each cylinder get a spark
only at the work stroke....and you will have quite a bit of trouble
even with that, as the ignition is set on the compression stroke, so
you could in theory squirt in the opposite cylinder with that signal,
, problem is thaty it is firing about 24-28 deg before TDC, you want
to squirt a sequential about 10-15 deg after TDC to avoid the back
pressure from the overlap.

It would of course be possible to work into it a delay, but then most
ignition systems will adjust it's timing, or be set differently at
the starting sequence....naa...I think I will pass on that,
 eventually this could be made working, but it will be a very
complicated FI control system.

You are right, on an O-200, or any aircraft engine with magnetos, no
matter how many cylinder or no matter what configuration,  I don't need
to go into thet engine and install a camshaft sensor, there are already
two rightly geared magnetos, that will make one turn for each time
the engine will do two rotations.

For now, I will not do an ignition system at all, but will come to it
eventually.

I have been looking ahead though, and made a little list that I want
to share with you about an optimum ignition system for aircraft use.

First, looking back to the dreaded magnetos, why are they there, and
what is good with them?

I mean really, what is good with them.......

It's a self generating ignition system that will spark no matter
what, as long as the engine is turning.

THAT quality, is unsurpassed, self contained and will continue to spark
no matter what.....can't beat that.

What is the downside...mechanical parts, points, springs, rotaty
distribution arms, internal sparks, and failures on those are not
unheard of. Weak spark, anemic weak spark, and very few magnetos can
be adjusted from the cockpit.

An electronic ignition system have everything taken care of, except
it is not self surviving in case of electric failure, it is electrically
dependent.

My optimal electronic ignition would be based on the basic concept that
made the magneto a winner, a self contained unit that will generate it's
own electricity, as long as the engine is running.

Magnet and a coil...that will be the start.

However, as I say I will not do the ignition system right now, I will
concentrate on the FI system.

I might take you up on the offer of making this system a batch fired
system, as you suggest, but will save the final decision until later,
depending on how intricate the control system will be for making it a
sequential system. The FI system will stay the same, it is just a matter
of how to control the firing of it.

The differenc in performance is not that much, not much at all, but
it just the teasing fact that there IS a difference, and if I can overcome
how to do it, i will do it...we will see, last word is not said
regarding that.

As I said earlier, I had some lesser knowledge about the rotaty
engine, and have read up on it now,I still have a lot to learn about
it, but it showed that I didn't even understand the basic principles
of it, thought I had it down, but oh no...shame on me...but hey....

I really appreciate all the help and steering me to what parts to use
and where to get them.

Suggestion, might be an idea to put it all out on the webpage, otherwise
you will have a bigger and bigger correspondence, all these small but
very valuable tips you are saying, where to get software to make
boards, how to get them, ABS sensors cheaper and works the same, and
so on...plus an update on circuitry....and so on. It will decrease your
workload with the public, and leave you more to do your research time.

I have a wish for you, I was originally curious and send you an e-
mail regarding the FI system and are getting a lot of mail back from
Rotary Engine, I really don't mind it, and there are some really
good pieces of info here and there, even if there is a lot of things
I really don't use, like how to cast side plates for a rotary engine
and such stuff.

Again I appreciate all the help in this.

Roger Isaksson

PS, ever heard of a six stroke engine, what do you think of that??? it's
a new way to run a cylinder engine, and get more energy out of it.

Intake stroke , like a four stroke.

Compression stroke like a four stroke.

Ignition and work stroke, like a fourstroke.

Exhaust stroke, will not happen, the engine compresses the charge again.

At the top, a diesel type injector squirts in water, that will instantly
make steam directly in the now very hot recompressed gasses, and
make an extra work stroke,

Final exhaust stroke, like a fourstroke.

Pretty neat...eh.

Roger

Yes I have. Invented by Bruce Crower. I have some reservations
about corrosion and deposits. Of course one must carry distilled
water.

The self contained ignition system of choice is a simple outboard
motor system.

Paul Lamar


Hi Roger,

The FI system needs to be set up from the start for batch or sequential. The
resistance of the injectors is different. It can be done with the same
injectors with changes in the ECU. I believe one of the after market
ECU's can
do this, but not inexpensive.

The 6 cycle gives me reservations also. I saw too many diesels that had
water
or coolant going through them that had major pitting in the head and piston
crown from the steam.

Dale Davies


Dale,

I really want a sequential system, but I can live with a batch fired one
also, because the difference is not that much, it is more in the fact
that there is a small difference and if it's there, why not go fo the
better option...... if possible.

As for using the same injectors for both, well at least when talking
four strokes we get into a timing problem, and it has to do with fuel
capacity per time unit.
A batch fired unit can deliver the fuel during the time the takes the
four stroke to go two revolutions. Pleeeenty of time

A sequential system has to deliver the same fuel load after the
four stroke has done it's camshaft overlap sequence, ( back pressure will
give a blow back just in the starting sequence) , and before the valve
closes on the intake stroke. I say BEFORE, because it has to deliver
while there is still effective flow into the cylinder, and you will not
get that effect close to the seating of the valve.

The idea with the sequential system is that it will deliver an exact
load of fuel every time, and not have a puddle of fuel waiting to be
delivered at the intake valve, as the timing sequence of the injector is
not dependent on the location of the rotation of the engine, on a
batch fired FI system, that puddle might be a bit bigger or smaller for
each stroke.

So it is a theoretical time of a quarter, but more practical time of
closer to a fifth, of the time, when a sequential injector can operate,
compared with a batch fired injector.

That means that if I want to deliver the same fuel load but only have
about a fifth of a time to do it on, compared with a batchfired system,
the injectors can electrically have the same properties,  I fully agree
with you on that, it is just a matter of figuring out the timing....but
the fuel delivery capacity has to be HUGE.

....so yes the injectors can be build according to the same electrical
principles, ....same .....same,  Just a matter of choosing a good big
volume injector.

.....lawn watering sprinkler with a solenoid on it ....maybe???????

Roger Isaksson