Misc: Everything Else Air Fuel Gauge 02 Sensor Lambda Sensor

Cyborg

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I'm sure 566 hrs worth is good for a free one way ticket to the laughing academy. Interesting idea using a knock sensor, although I wonder if it can distinguish an actual knock from all of the other thrashing and vibrating going on.... I have no idea, but riding atop a liquid cooled modern multi cylinder would be a much more civilized ride for the sensor. It will be interesting to see how well it works...certainly worth a go. If you purchase a sub harness for the sensor, save yourself some heartache and make sure to get the new improved version that is rat resistant. It will likely have little drawings of rodents on the sheathing or a rat with a line drawn through it.


When they designed the Honda CX500 Turbo, rather than use knock sensors, they were able to program the ECU to avoid those conditions. Always thought that was a better way to go, because the knock sensor is telling you that things have already started to go to hell in a handbag.

I'm trailing far behind you.... but I did TIG weld the bung in place.

Does a bunsen valve's change to reversion in turn cause a chance to A/F ratio.... as in once the valve is removed, does the engine run richer?
#Shroderingerscat
 

Magnetoman

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I'm sure 566 hrs worth is good for a free one way ticket to the laughing academy.
If I survive getting the Excel program to work without it sending me there, dealing with the data only will take a few clicks of the mouse (says he, having had more than enough experience with such things to know better...). My hope is I'll be able to automatically generate a scatter plot, with the density of data points graphically showing what the AFR actually looks like as a function of throttle position.

Cyborg said:
BTW.... what are you using for an accelerometer?
Part of my new setup is an Innovate LMA-3 which includes two internal accelerometers.

Interesting idea using a knock sensor, although I wonder if it can distinguish an actual knock from all of the other thrashing and vibrating going on....
If it were made by an American or Brit I'd be skeptical, but it's made by a Canadian, and he claims it can do it, so it must be true...

Two things prompted my interest. The first was when I got my Catalina running a few years ago and I turned off a fast road onto a small, uphill street going too slow in a gear that was too high, the engine started rattling. I quickly grabbed the magneto advance lever and the rattling stopped. The second is my Competition has a 10:1 piston and needs high octane no matter what. I use a super-expensive octane booster that converts pump fuel into 100 octane ((R+M)/2) at a total cost of ~$8/gallon. Anyway, I wondered if a knock sensor might save me money if using it let me determine that less of the octane booster was sufficient (the savings in fuel cost could pay for the knock sensor system in less than 100,000 miles... but, that's not the point).

As opposed to the dull thud of an engine, or the rattle of parts falling off, "pinging" has a quite sharp sound so there is reason to believe an appropriate notch filter could isolate the desired undesirable signal from the normal sounds. The control unit has an adjustment to set the cutoff, and my hope is the unit will be sensitive enough to detect knocking before I do, either by hearing it despite the sound-deadening of my helmet, or the more obvious clue that the engine abruptly stopped turning.

Does a bunsen valve's change to reversion in turn cause a chance to A/F ratio.... as in once the valve is removed, does the engine run richer?
Interesting question. A bunsen valve represents a very low restriction to the outgoing exhaust, but there could be some effect on the strength of the reflected pulse since the pipe no longer would have an abrupt exit to the outside world. If its presence weakens that pulse, and if there is a lot of valve overlap, it would have an effect on the filling of the cylinder.
 

Cyborg

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Well if you ask me, you are treading down a road laced with land mines. What happens if the undesirable signal drives you to the point where you seriously have to consider programable electronic ignition with a VOS to switch maps? Going to be a tough pill to swallow for a magneto man.

As for the Bunsen valve, I figure if it is able to keep interloping O2 molecules away from the A/F sensor, then it “must” be having an effect on reversion which in turn has an effect on mixture.... especially with cams like the Gold Star’s or Mk2’s. If that video (post77) about the bolts and thumbscrews is to be believed, then the presence of Innovate sniffer itself would cause a change. The question is how to determine that. Now we can’t just let that question fester..... but how do you answer it?
 

Magnetoman

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What happens if the undesirable signal drives you to the point where you seriously have to consider programable electronic ignition with a VOS to switch maps?
There's no danger of that happening. My self-imposed (or self-inflicted) approach to old motorcycles is to keep them as original as possible, within reason. The "within reason" gives me the wiggle room to put a Concentric on a Gold Star, but not a Mikuni. I also enjoy (mis)applying modern technology to old motorcycles, but to make them work up to the full potential of their original designs and components, not to "upgrade" them. My approach gives me the flexibility not to paint myself into originality corners, but ensures I get the full "old bike experience" when riding those machines. Other bikes given me EFI, electric start, disk brakes, etc. when I want a different experience.

As for the Bunsen valve, ... The question is how to determine that. Now we can’t just let that question fester..... but how do you answer it?
It actually would be quite straightforward to answer. Someone with a modified pipe like mine, where the sensor barely protrudes, checks the AFR at all throttle settings, then slips a Bunsen valve over the end of the pipe, and checks again.

The wording with "someone" and "like mine" wasn't accidental. It's easy to get lured down some else's rabbit hole when you still have plenty to do down your own.
 

Cyborg

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But..... If installing the bunsen valve changes the A/F reading and presumably it will or we wouldn't have a bunsen valve to start with, all we would see is the change. Is the change only due to the valve preventing O2 from getting back up the pipe and altering the reading... or is it because the reversion is reduced and the intake charge is altered.... or is it a sum of the two? Is the baseline (obtained without the bunsen valve) accurate or has it been altered by those interloping O2 molecules. Again.. presumably it has. At the end of the day, you will have a motorcycle that runs and feels like all is well, but that of course is not the point. Cling to the rim of that rabbit hole all you want, but eventually all those years of academia will weigh you down and your compulsion for the truth will get the best of you.
 

Magnetoman

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Is the baseline (obtained without the bunsen valve) accurate or has it been altered by those interloping O2 molecules. Again.. presumably it has.
Not so fast with the assumptions. The environment for an O2 molecule in the exhaust pipe is like that in a Tokyo subway car at 5pm. The last person who manages to force his way through the door doesn't proceed on to the back of the car, but the pressure due to his presence does make it to the back of the car. Similarly, an O2 molecule sucked back up the exhaust pipe doesn't make it all the way to the exhaust port, but the pressure does. As long as a minimally-intrusive oxygen sensor is placed far enough up the pipe that oxygen doesn't make it that far then its reading will not be affected by the fresh O2 molecules that are further downstream.
eventually all those years of academia will weigh you down and your compulsion for the truth will get the best of you.
In times like these I take refuge in the words of Voltaire: 'Toute phrase qui a besoin d'explication, ne pas mèrite pas qu'on l'explique' ('Not everything that needs explanation, merits explanation'). Also, an invaluable piece of advice I was given years ago, after I had accepted my university position but before I had taken it up, is relevant. A good friend with infallible political instincts (who rapidly rose to become Chancellor of the entire ten-campus University of California system) said to me that "You probably think everything worth doing is worth doing well, don't you." "Yes, yes," the young me eagerly responded. "Wrong," he replied, "Not everything that has to be done actually needs to be done well, and if you don't learn to correctly prioritize your time you'll be a failure."

As an example, I had no choice but to sit through countless meetings during my years at the university. But, I quickly developed the skill to hear the general drone in the background as I read research papers, edited manuscripts, or did other work that was important to my career. When a certain lull in intensity happened I knew it was time for a vote. So, I paid attention for the next 30 sec. and then went back to doing what did need to be done well. In contrast, when some important task needed to be done administrators would appoint me Chair of a committee tasked with getting it done.

In the context of motorcycles, I've heard it said that someone either does quality work, or sloppy work, but the same person can't do both because sloppy work causes bad habits. That may be true for some people, but it's definitely not true in general. But, I digress...
 

Cyborg

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I think where I went wrong with the assumption was... between this thread and the other one with the picture of the Bunsen valve, I “assumed” you were using the valve with your test pipe and A/F sensor setup. I guess my new assumption based on your response is that you only use the Bunsen valve when using the sniffer?

Using your Tokyo subway analogy, when the new guy gets on, the pressure from his presence does indeed make it to the back of the car. Wouldn’t that in turn mean that an O2 molecule that had just passed the sensor get shoved back across the sensor? Back and forth like the slinky in the video.....

Sage advice from the Chancellor, but do you subscribe... a true believer? I think not given the fact that you showed up here a month later with a LMA-3 and a knock sensor to boot.

I developed the skill to deal with that general drone at an early age. Got me kicked out of school a few times due to my inability to recover seamlessly. One time in English class, the teacher had asked me a question.... I thought that I had absorbed enough of his droning to answer the question. “Jesus Christ “ I replied.... apparently it was the wrong answer and our normally semi comatose teacher went berserk and threw me out of his class. That was pretty much the end of my high school education, so if I mix up my pronoun order, you’ll have to excuse me.
 

Magnetoman

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I guess my new assumption based on your response is that you only use the Bunsen valve when using the sniffer?
That's right. I have three Gold Stars and a couple of extra header pipes in "non-concours" condition so it made sense to convert one of those. I haven't used the Bunsen valve since making this conversion since I haven't tested any non-Gold Star bikes since then. But, if I did, I'd use the Bunsen valve.
Using your Tokyo subway analogy, when the new guy gets on, the pressure from his presence does indeed make it to the back of the car. Wouldn’t that in turn mean that an O2 molecule that had just passed the sensor get shoved back across the sensor? Back and forth like the slinky in the video.
If I understand, you're worried that even though the sensor is located well upstream of the tailpipe it would triple-count any unfortunate post-combustion O2 molecules in the vicinity as they pass the sensor, are then shoved back past it in the opposite direction by the reversion wave, and then pass it a third time when they're finally headed toward their escape out the end of the pipe. While that might happen, the successive passes of the molecules are separated in time so they only get counted once at each time interval, i.e. the sensor isn't fooled into thinking the same 02 molecule is a set of triplets since it passes by the sensor at different times. Further, if "old" O2 is near the sensor it means "new" O2 from the subsequent combustion cycle can't have made it that far to enrich the O2 so at all times the instantaneous ratio of O2 to CO2 is correctly sensed.
Sage advice from the Chancellor, but do you subscribe... a true believer? I think not given the fact that you showed up here a month later with a LMA-3 and a knock sensor to boot.
" A foolish consistency is the hobgoblin of little minds." Of course, even if Emerson's observation is true, it doesn't mean inconsistency is necessarily better...
I developed the skill to deal with that general drone at an early age.
Going way off topic, it turns out I'm on the board of directors of a foundation based in the UAE. For our last meeting the plane out of DFW was delayed by mechanical problems, which made me miss my connection at Heathrow so I had to wait all day for the next one. As a result, instead of getting a full night's sleep after I arrived, I landed in Dubai shortly before the meeting was to start. I made the driver take me to the hotel for a quick shower and then to the meeting, which ended up being conducted 98% in Arabic (of which I can recognize maybe six words). Despite my jet lag and lack of sleep, or maybe because of it, I was able to follow the flow of the meeting all day (helped by a detailed agenda in English as well as Arabic), and was even able to contribute -- in English -- from time to time. Apparently, all meetings everywhere in the world are essentially the same so to serve as a committee member you don't have to speak a word of the language to basically know what is going on.
 

Magnetoman

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The first photograph shows work in progress. It's actually nearly done, but I'm waiting for another LED to arrive before drilling the final holes. Shortly after the LED arrives this will become the upgraded Mark II "universal" instrumentation package that I've designed to clamp to just about any set of handlebars. What the photograph doesn't show is brazed underneath is an array of seven nuts to allow the clamp, shown in the second photograph, to connect to the platform as close as possible to the center of gravity irrespective of the location and orientation of the clamp on the handlebars (e.g. clip-ons are nearly horizontal, the unobstructed segments of ape hangers are nearly vertical, and typical handlebars are somewhere between these extremes).

The Manfrotto "Super Clamp," repurposed from its camera holding tasks, is perfect for this. It has a rated capacity of 33 lbs. but only will be holding less than 3 lbs. including the Manfrotto universal joint. Together they can position the platform in the best location on just about any bike, as well as hold it so it doesn't vibrate any more than the handlebars themselves do.

Mounted on the platform will be an Innovate MTX-L air/fuel gauge along with a data logger that will record data from that meter as well as from a "universal" throttle position sensor (that also clamps to handlebars), tachometer, accelerometer, exhaust gas temperature (EGT) sensor, and knock sensor. As mentioned previously, engines "feel" like they're running well with Air/Fuel Ratios anywhere between ~10:1 and ~15:1 so accurately adjusting the several circuits and jets in a carburetor for either max. h.p. or max. fuel economy requires just such instrumentation.

For someone who doesn't want to permanently install a wide-band sensor in their vehicle Innovate sells an "exhaust clamp" (sampling attachment) that inserts in the end of the exhaust pipe to sample the mixture. The next photograph shows the sampling attachment that I bought with my original meter.

The design is like a Pitot tube, with the exhaust flow past the holes in the side of the shorter tube reducing the pressure and drawing the mixture in the end of the longer tube, past the sensor, and then back out again through the holes in the shorter tube. However, this sampling attachment comes with the warning that it probably won't work on a single-cylinder engine (or a twin with separate pipes) because air is sucked back up the exhaust pipe some significant distance on each cycle. Unless the tip of the sampling unit is further up the pipe than that point, it will give bogus readings. Which it does on my motorcycles. I overcame this problem with a "Bunsen valve" arrangement I discussed some time ago, but it wouldn't be an ideal solution for many people.

So, how far does air get drawn back up the pipe? Despite the relatively short pipe currently on my Catalina I know from the behavior of the meter that the location of the sensor doesn't suffer from the air reversion problem. It happens that the Catalina's "silencer" doesn't have anything in the center of it so it's a straight shot all the way to the bend in the header, just past the "permanent" sensor. Since the sampling unit is pretty much useless as-is, I extended it by 10" so it now reaches to the location seen in the photograph. This will let me answer the question at the beginning of this paragraph.

As a result of my instrumentation upgrading process I now have a second Bosch sensor and a separate control unit for it. Which means I can have my upgraded Mark II instrumentation package in place, but also use the elongated sampling unit to determine the depth into the pipe where reversion no longer is a problem. With a helper, AKA long suffering wife, I can check this from idle up to at least a few thousand rpm while the bike is sitting in the driveway. Note that I'm not suggesting determining the jetting this way, since it wouldn't be under load, only determining the depth of the reversion.

This elongated sampling unit has two separate functions: as a test probe to determine the depth of reversion, and to determine the AFR on the road without having to modify the exhaust pipe or use a Bunsen valve. However, the latter relies on the design of the silencer so it won't work on all bikes. For example, it fits up the pipes of a Matchless G80 and Triumph 500, but not a Trident. Still, for bikes where it will work it is an alternative to either a Bunsen valve or permanent modification of an exhaust pipe.
 

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