Jump to content

Banjo

Regular Member
  • Posts

    1,604
  • Joined

  • Last visited

  • Days Won

    69

Everything posted by Banjo

  1. Hi Aldous ! Welcome aboard ! Where are you located. Bonnets, guards & doors are big heavy items, & very expensive to package & freight, unless you can pick up yourself, if their location is relatively local to you. I have a number of KE55 2 door pillarless coupe panels, & a bonnet, but not sure whether they are interchangeable with the lift back model. Cheers Banjo
  2. Well the 200mm dia. aluminium trigger disk is working better than I could have dreamed of. The TAARK dual Hall Effect sensor, is far more sensitive than the "ebay" sensors, I had been experimenting with. Because the dual Hall effect sensor is so sensitive, to both North & South pole magnets, with air gaps achieved of 3-5mm; there has been no need to revert to larger diameter 10mm rare earth magnets. In fact if I had used them, the break in the pulse train, as the sensor passes from one magnet to the next; would have resulted in a very short break between pulsing signals. I've stuck with the 4mm dia. magnets, & pressed the 36 magnets into the disc, as follows . . . 17 south pole: 1 north pole: 17 south pole: 1 north pole. The outputs from the two (2) north & south pole sensors are "OR'd" together, with the 34 pulses (2 x 17) from the south polev magnets; to produce a continuous unbroken string of pulses, that will be used for high resolution of crankshaft rotational speed calculation. The two (2) north pole magnets, spaced exactly 180 degrees apart on the alumimium disc, will produce a total of four (4) pulses, for each full cycle of the engine, whiich is 2 revolutions of the crankshaft, or 720 degrees. The pulse from these two (2) north poles will produce 4 equally spaced pulses 180 degrees apart, for every full cycle, or two (2) crankshaft revolutions. These can be used, in conjuction with the Camshaft Position Sensor pulse, to direct the outputs sequentially, based on the 1-3-4-2 firing order. If it was a 6 cylinder engine, the magnets would be pressed into the aluminium disc, as 11 south, 1 north, 11 south, 1 north, 11 south, 1 north. Again a total of 36 magnets, but just arranged differently. Nice clean square pulses on the CRO, from the trigger wheel at about 1500 RPM Opto Couplers X 3, with "ORing" circuitry for continuous stream of "speed" pulses, With a few LEDs, so I can see clearly, what is happening. All good fun, & almost time to start a "bit of coding", to tie it all together. Cheers Banjo
  3. Hi Matthew, Glad you sorted that one out OK. Everything electrical in a car, needs a good earth; particularly something that sources or consumes large amperes, such as an alternator. Good one ! Cheers Banjo
  4. Hi Matthew, Go to this link in Rollaclub. https://www.rollaclub.com/board/topic/73991-ke20-alt-wiring/#comments I found an olde post where someone else got caught doing an alternator upgrade, & in that post is a sketch, that should get you sorted. Yell out, if you are still having issues. Cheers Banjo
  5. Hi Matthew, Sounds like there is something amiss. I do recall there was something different with the way the charge light wa needed to be connected up. Let me take a look at my KE30, & I'll see how it was done. Too long ago, to remember the details. Cheers Banjo
  6. Hi Matthew, Can you do a quick sketch of how you have wired it up ? I've done that mod years ago on an early Rolla, & don't ever recall having any real issues. If you supply a sketch, We'll soon see where the issue is. I'm presuming you have removed & disconnected the olde external regulator box ? Cheers Banjo
  7. Hi Aaron, Where in Qld. are you located ? Cheers Banjo
  8. . . . . . . . . Or the Race Track ! No problem getting this one through Scrutineering !
  9. I'm really impressed with the options on this particular model. Most Rolla's only have one petrol filler cap on the back left guard. This one has a second entry to the petrol tank, right next to the boot lid; where you can fill twice as fast, using two (2) bowsers, at the same time, when at the petrol station ! Magic ! Banjo
  10. Welcome aboard; & what a find ! It appears that the speedo, is indicating it has travelled just under 40,000 klms. That seems unlikely. if the car has been sitting there for 25 years, then when it entered the junk yard, it was already 28 years olde. Highly unlikely, that it would only travelled approximately 1500 klms each year since new. Where about are you located, & are spares available readily ? Are you " enticed", to return it to original, or upgrade it all round ? Before, I removed a bolt or panel anywhere, I would see if you can get the engine going, although, that is a big ask, as the engine has been in the weather, without a air cleaner on it, so may well be "frozen". Congratulations, & let us know what you decide, & start a thread, on Rollaclub, & keep us posted. We love these type of "projects" Cheers Banjo
  11. Hi Aaron, Can't view your pics. Appears unless you are a Telstra customer, you can't access them.
  12. Over the weekend, I experimented a little more & resolved a couple of issues. The 12mm dia. Hall Effect sensor, I was using (NJK-5002C) is certainly a useful device for proving, that this experiment will work. It reacts to a south pole magnet face only. I had played with a 8mm dia. similar Hall sensor, that turned out, to switch to both north & south poles, & even to the aluminium plate if it was very close ? ? ? It It was a LJ8A3-2-ZBX. I gave that one away, as being useful, or appropriate for this application. So I now have two NJK-5002C Hall sensors side by side. One counting the 18 off 5mm dia. south pole magnets around the peripheral of my 150mm aluminium disk, without any missing magnet/tooth. The second Hall sensor, is 20mm further inboard on the disk, in-line with the first sensor & disc centre point; but only picks up the one "sychronisation south pole magnet", per crankshaft revolution. I hooked the dual channel CRO up to the two sensors, & they were clean, & no missing pulses at all, with the engine on the stand, run up to a bit over 3000 RPM. With the 10mm larger dia. magnets I will be using later, on the 200mm disc; the magnetic field will be stronger & I can probably incease the air gap between disk/magnet face, & the sensor face. Currently running at about 2mm, but with a larger & stronger magnet, it should be possible to achieve gaps of 3-5mm. The rare earth magnets, come in a multitude of difference sizes, & there are three (3) commonly available strengths; of N35, N50 & N52. N52 is the strongest. I did resolve another issue I had, which was "air gap" variance, as a result of slight run-out of the aluminiun disc, in the "planar mode" (across the face of the aluminium disc). The 150mm & 200mm aluminium disks I am using are 6mm thick. They are very rigid. The are mounted primarilary; via the crankshaft pulley centre bolt. There are additional threaded holes in the crankshaft pulley for either attaching a "puller", to remove the pulley, or to sandwich an additional pulley, as in the case of the 5K engine, which had up to three (3) pullies, depending on it's application. I have used these to locate the aluminium disk, "rotationally". However, when adding a nut to the studs, is distorts the aluminium plate, ever so slightly, however well you try to shim it at the back. I decided to remove the nuts, & the air gap then did not vary at all. I could cut the studs down a bit, put a screwdriver slot in them, & "thread locker" them in, & they will still act as locators of the trigger disc. Alternatively, I could dispense with them altogether, & just fit a slightly longer crankshaft location key, in the keyway; & file a small keyway in the aluminium disk, at the point where the synchronisation pulse appears at it idea position, (encoder wise). A lot of ECU decoders, don't like the sychronisation pulse occurring at the same time as any other event. I may have to move the sychronisation magnet, so that it occurs between the pulses on the outer edge, rather than in line. Easy fix, if necessary. I have discovered, in recent days, that there is available, a Hall Effect sensor, for automotive applications; with two (2) sensors built into the one housing. https://www.efisolutions.com.au/dual-channel-hall-sensor-suits-taarks-hall-kits One sensor provides an output, when facing a "south pole" of a magnet, & the other, provides a sencond output, when a north pole face comes along. This provides a great opportunity, to simplify the system, with just two sensors, rather than three, for sequential ECU operation. It would simply involve fitting one of the magnets, on the peripheral of the disk with a north pole. (press the magnet it the opposite way around). This would result with a synchronisation pulse, once per crankshaft revolution, from the sensor reacting to the "north pole". The second Hall Effect sensor, within the housing, would react to 35 of the 36 magnets around the peripheral, of the disk. It's output would in fact appear to have to a "missing magnet". However, if the outputs of both sensors were "OR'd" together, the result would be a continuous string of pulses, with no missing pulse at all. One other thing I discovered, in recent days, is that the Hall Effect sensor, inside the sensor housing, are usually much smaller in area that the cross sectional area of the sensor housing itself, & is not necessarily at the centre of the sensor face, I broke one sensor accidentally, & discovered this. So very pleased with progress to date, & now it is time to replicate this on a 200mm aluminium disk, with maybe just two (2) physical sensors, instead of three. For Waste Spark/Batch Injection, you could get away with just one sensor housing, with two (2) indivual sensors therein. 1. Crankshaft Speed Sensor CKS 2. Camshaft Positianal Sensor CAS 3. Crankshaft Synchronisation Sensor SYN Cheers Banjo
  13. The 200mm x 6mm thick aluminium disk arrived in the mail this afternoon. I purchased the blank on ebay, from a company in Victoria, who mills them. Very good quality & service ! Bit over $ 21.00 + postage. So it's a "blank canvass", & not having any CNC equipment, I had to go back to school, to "geometry days", to prepare this plate for drilling. I experimented with the 150mm dia. one I made previously, so had a plan. If anyone, wants to replicate this, it is quite easy. Just takes a bit of time & patience. It is not one of those activities you can rush; because if you stuff it up, then you are back to "square one". The first thing we need to do, is find & make the centre of the aluminium disc, as that is absolutely crucial, if it is all going to work. I tried all geometrical ways to find the centre, but each time, the centre was off a mm, or two. My final technique required no tools at all, or geometric instruments really. Technique: 1. First clean & dry the disc carefully, to remove any oil. 2. Lay the disk on a clean sheet of A4 white paper. ( 200mm dia. disc, is slightly narrower, than the A4 sheet. 3. Holding the disc down hard against the paper, run a Artline pen (0.4 or 0.5) around the edge of the disc a couple of times. 4. Remove the disc, & taking a pair of large, sharp siccors; cut around the edge of the circle on the sheet of paper. When you cut the paper, cut carefully around the inside of the line, rather than the outside. The result should be a white circle with little or no remains. of the line you marked. 5. Lay the paper flat, & carefully fold it in exactly half. Rub along the crease line, while folded, so the crease line is very "distinct". 6. Take the semicircle of paper, & again fold it exactly in half; & again, ensure the crease line is very defined. 7. Now open up the folded circle of paper, & the point where the crease lines cross, is the exact centre of the circle. 8 Draw a straight line across the circle of paper, on both of the crease lines. 9. Using the centre point, scribe a circle around the circle, just in from the circumference edge. In my case that was 10mm. 10. Take the biggest protractor, you can get hold of, & placing the cross hair point on the centre of the circle, mark the point around, at the number of degrees you need, which will depend on your preference. I wanted a 36 tooth/magnet trigger wheel, so each mark was spaced at 10 degrees. 11. What you finish up with is a circle of paper, that looks something like this. 12. Now, take the circle of paper & lay it on the disk. I now becomes obvious why I suggest cutting on the inside of the circle line intially, as it is extremely difficult to centre it, if the paper is just overhanging the edge of the disk. 13. I suggest doing this, with the disk & paper hanging slightly over the edge of your table or desk; so that when you have is perfectly centred, you can apply 4 or 8 pieces of clear sticky tape, that sticks to the underside of the disk. 14. So that's it ! Now place the disk, & paper template on a bench, & with a small, sharp centre punch, carefully "centre punch", the central point of the disk, & all the peripheral holes, that are to be drilled for the magnets. 15. Drilling the holes should ideally be carried out, using a drill stand, with the aluminium disc, clamped down. Always start off with a small drill, & then keep enlarging them, until you get them to the size you need. The outer ring of holes, where the magnets are to be fitted, should be drilled about 0.5mm undersize, to the diameter of the magnet; so the magnets can be pressed into the alumium disk. When I get to the next stage, I'll post the results. P.S. Anyone wanting to know how Hall Effect sensors work, would find this article interesting. https://www.electronics-tutorials.ws/electromagnetism/hall-effect.html Our application here, is passing the pole of the magenet, across the face (sideways detection) of the Hall Effect sensor. Cheers Banjo
  14. Been doing a bit of experimenting with an aluminium disk (150mm dia.) with rare earth magnets, with none missing. I then have an additional single rare earth magnet, in-board slightly, in line with one of the 18 magnets around the circumference. The experiment has been very sucessful, as my objective was to build a "flying magnet" trigger disk/wheel; without any missing teeth or magnets. The next step, is to move up a 200mm dia. disk, so that I can space the magnets around the circumference, with a slightly larger distance between them. Currently, I have a bracket holding the two (2) Hall Effect sensors, mounted from the block, using the two threaded holes for the A/C mounting. I have recently also located a Hall Effect sensor, that has two sensors in one housing. One detects south pole magnets, & the other north pole magnets. https://www.efisolutions.com.au/dual-channel-hall-sensor-suits-taarks-hall-kits It should then be possible to fit 36 off disc magnets around the circumference of the 200mm aluminium disk. 35 would be south pole facing the sensor, & one would have the north pole facing the sensor. The single from the north pole sensor, would be the synch signal, & the same north pole signal, could be "OR'd" with all the south pole signal pulses, so that a continuous stream of pulses, with no missing teeth, is possible. Cheers Banjo
  15. My KE30 is not going off the road, unless it's cancer gets so bad, I have to bury it. As for gearbox issues, there is a very simple solution, that I envisage accomplishing. Simply leave the gearbox stuck, permanently in top gear, & then develop the engine, so that it has so much HP, that you never have to have change gear again. You'll always be able to reface clutch plates ! https://www.youtube.com/watch?v=dKGiQgxgVzg Cheers Banjo
  16. Hi Pasha, A very easy, & worthwhile conversion. Certainly, starting with a manual, rather than an auto, as I did, makes the amount of work a lot easier. 5 speed boxes are getting harder to come by, & many are now "long in the tooth". (No pun intended) The best 5 speed gearbox, is the one that came out in the KE70. It has the gearstick back a bit further, than the earlier K50 gear boxes. It places the gearstick in a really good position. Only trouble is, that if the KE70 5 speed gearbox you get hold of; needs some parts; things like bearings, are getting very hard to come by. If you use the 5 speed box from a KE70, makes sure you get hold of the rear gearbox cross member. You may have to "massage" the hole in the top of the floor transmission hump, but that is best done, after you do a trial fit. Other than that, it's all very easy. Before you start, just check what diff ratio, your KE30 has. There was a couple of ratios used, & the KE30 auto had a horrible one, like 4.3 or something. The best diff to go with your 5 speed box, would probably be a BW one, where I think the ratio was something like 3.98, or thereabouts. Also, make sure the reversing light switch on the gearbox, is working, before you install, & has wires attached long enough, as once it is in the car, up in position, it's almost impossible to get at the reversing switch. Lets know how you go. Where are you located ? Cheers Banjo
  17. A timing light is one of the most useful tools you can have, besides a 10, 12, 13, & 14mm combination ring & open ended spanners; & a hammer as well. Don't need a fancy one, where you can dial in degree delays itc. Just a plain no frills one. It tells you dynamically; more than whether the timing is correct. It also tells you whether the auto advance & retard mechanism, in your dizzy is working or not. Would not be without one. ebay is your friend there ! $ 30+ approx. Cheers Banjo
  18. I just added one answer to my previous post. The plug in your hand I don't instantly recognise. Does the lead on which this plug is, go back into the main wiring harness ? Is your KE38 an auto or manual ? I listened to your video, & although it doesn't appear to have all the exhaust system connected, as yet; if the timing is out, it is not very much. Do you happen to have a timing light to check it dynamically ? Cheers Banjo
  19. Hi Luca, The little carbon bush that is "spring loaded" in the inside centre/to of the dissy cap, is quite often the problem. The fine spring behind the carbon rubbing bush actually passes the HV current, & can corrode to become very thin, then break.. However, I have had a centre bush fairly recently; collapse altogether, & the engine ran perfectly. Probably because I was using a Hi Volts output coil, which allowed the spark to jump the large gap. Unless the four (4) posts in the dissy cap, are very, very corroded, such that the gap between rotor tip, & 1, 3., 4, & 2 posts in the cap, is very large, it can sometime make the engine run better. The spark will often jump a bigger gap, in "free outside air"; than at the spark plug tip, under compression in the cylinder. This technique was used regularly by racers, in the old days, to increase the HV supplied to the spark plug. That black lead with a yellow strip, is an engine earth or ground cable. You''ll probably find the other end is connected to the engine block, towards the rear. The bit you show in your hand goes to the head and/or rocker cover. Have you had the dissy out ? if so it maybe out a little. There are heaps of instructions on the forum, regarding how to refit the dissy, & get the timing right. Cheers Banjo
  20. Yep ! Always need that cooling water ! Was thinking about "plopping" it all in my neighbours "swimming pool", but She is a bit of a dragon, so I don't think that would end nicely. The electical generator has always been my preferred option. I guess I am still going to need a clutch & a straight through gearbox, to actually get it started, & up & away. Talking about starting; I'm actually experimenting at present. Lots of people complain, about no instant starting with ECUs, as it can take "up to two revolutions of the crankshaft, before the ECU "synchronises", & then fires a spark plug for the first time. Some ECUs apparently, start in waste spark, & then as soon as it fires, it switches back over to sequential ignition & injectors. I'm looking at a way of getting it to fire within 1/4 of a turn of the crankshaft, under the starter motor. Requires another sensor, but that's no big deal. Just drilling up a new trigger wheel/disk, to see if it is possible. Would love to get away from having that "missing tooth" requirement, on the primary crank trigger wheel. What system do you use on Josh's rally cars ? Cheers Banjo
  21. Not quite to that point, as yet. Think you & I canvassed this idea some time back. Have looked at a few utube videos, for D.I.Y. at home; using water type engine dynos, which can be tricky. Simplest system seems to be to use a automatic transmission torque converter, from a car a bit bigger than our Rollas, & hang a bar off it rotationally, to which we can add or subtract weights, to produce a quanative load, in foot pounds or whatever ? Any suggestions gratefully received. Cheers Banjo
  22. Tah Luca ! Yes it is a lot of fun. I'm not an expert on these things. Expert: Ex = A has Been Spurt = A Drip Under Pressure I'm learning just like everyone elso, but appreciate all the feedback & info that others put on the web & RC Forum, so feel obliged to list here, anything I discover, or gain an understanding of. They say a picture tells a thousand words, so that makes it more interesting. At the moment, I'm toying with the idea, of trying out a three sensor system, instead of two. If you go for a waste spark, & batch injector system, you can get away with a single crank sensor system, using a missing tooth trigger wheel. With crank + camshaft position sensor, you can do full sequential ignition & injector firing, but the crankshaft trigger wheel, must still have a missing tooth/teeth. With three (3) sensors, you can also do full sequential ignition & injectors, but you don't have to use a missing tooth crankshaft trigger wheel. The missing tooth/teeth wheels seem to cause a lot of issues, when sensors miss reading a tooth. Without a missing tooth, the RPM information is updated more often, & is more accurate. I already have a third sensor on the flywheel, which would very accurately provide the exact position of the crankshaft. You can achive the same, by looking for the next tooth, on the crankshaft trigger wheel, after the camshaft position pulse. However, the camshaft pulse timing can vary due to slop/wear/etc. in the timing chain & sprocket, & distributor/oil pump lelical gear. I'm not sure that a lot of aftermarket ECUs provide a decoder, to accomplish this. Need to do a bit more research. If anyone on here has "been there", or has info on this aspect, I'd love to here from you. Cheers Banjo
  23. The circuit itself is quite simple. The Hall Effect device Proximity switches I used (NJK5002C), actually have an LED built into the case at the back, where the lead comes out. However, I wanted to have both LEDs in one location, where you could view them side by side. In practice, the Hall Sensors are located in the 'Camshaft Position" dizzy on the side of the engine; & the Crankshaft position trigger wheel, is down at the very bottom of the front of the engine; rendering it difficult to view both LEDs directly, at the same time. As the Hall Effect sensors are powered by 12Vdc, I wanted to ensure the signal sent to the ECU trigger inputs for cam & crank, were optically coupled; which helps reduce any hash on the 12 volt line, being transmitted to the ECU trigger inputs. The MOC5007 does this well, with a photo diode internally, which completely isolates the input from the output of the device. As well as that, the MOC5007, has an Schmitt differential hysteresis final stage; which again, helps produce a very clean output signal. The output is an open collector output, so that its output load can be tied to a supply other than 12 volts, if necessary. I have chosen to tie it to 5V, so that the signal can be directly fed to the ECU, which will have a 5 volt rail, in the case of the Speeduino ECU. The 10K ohm load resistors could possibly be omitted, as most ECU crank & cam inputs, have pull-up load resistors, either permanently in place, or optional, with a link or the like. The "Crankshaft output signal" from the MOC5007 is fed directly to the “clock input” of a CMOS 4060 counter IC (pin 11). The counter, has it's initial count set to zero, at power up, by a monostable pulse directed to the "reset input" (pin 12). The counter then starts counting from zero, & will produce a output at a count of 32, which is turned into a monostable pulse, to drive the BC547 transistor & “crank pulse” LED. There is enough drive, to do away with transistor, if the LED is needed to be powered by the 5 volt DC supply. So a simple circuit that works well, & although not totally required, for ECU operation, will make trouble shooting & understanding the operation of the crank & cam shaft inputs very clear. Note: Just a word of warning. The NJK5002C Hall Effect sensors have an unusual colour coding for the three wires coming out of them. Brown: +ve supply voltage 6-36V DC Black: Open Collector switched output Blue: -ve supply connection
  24. One of the problems with trigger wheels, is the need for specialised equipment, to check that the multiple critical timing signals, from the crank & camshaft position sensors, are working properly. There was something to be said for the simplicity of the “Kettering System”; we are used to; where if your engine did not fire, you quickly removed the dizzy cap, & could quickly decide what was the culprit; sometimes just visually, or with a simple screwdrive & trouble light. With the trigger wheel in particular, this becomes even more critical, once you understand how the ECU interprets the signals coming from the VR or Hall Effect Sensor. eg: If the air gap of the sensor from the trigger wheel teeth, was a little wide on just one or two teeth, such that a signal was not produced from those particular teeth; then those missing pulses, to the ECU; could well appear as if they were the intentional missing teeth on the trigger wheel, & throw the complete timing out. Take the case of say a destroyed/missing magnet, due to being dislodged by the centrifugal forces on it. Same result; the timing gets thrown out completely. I decided that I would build a simple opto-coupler & LED visual system, that allowed very simple & quick, verification, that the signals from both crank & cam sensors were working correctly, while cranking the engine. The results were a simple small “black box”, housing the electronics, with two (2) visible LEDs, that was mounted near the front of the engine. Placed there, it could be viewed, if for instance, you were turning over the engine by hand, very slowly; to check whether every tooth, or magnet, in the trigger wheel, was creating a pulse. I posted a picture of this little box, earlier in this thread. However, there was an issue. When the engine was being cranked, with 35 magnets (36 – 1) producing 35 pulses every revolution, visually; you cannot see the clear make & break of each trigger wheel transition, & the LED looks like a blur, for the crankshaft LED pulses. So I decided that if I built a counter, that counted the individual teeth/magnet signals, & only produced a LED pulse once the count was reached; say once per rev; it would clearly indicate that all was good. I would still retain the LED that indicated every tooth or magnet transition, so that you could turn the crankshaft over with a ratchet & socket, & see every individual tooth pulse, if needed. The result was even better than I envisaged. The counter I used had an output for a count of 32, which was close enough to one revolution of the trigger wheel/disk. I could have made it count exactly to 35, or 36; but that would have required an extra IC chip, & the result would not be noticeable. Cranking the engine with the spark plugs removed; which is the fastest cranking speed possible, gave a clear visual indication of the cam, crankshaft pulses, plus a clear LED pulse output for approximately every revolution of the crankshaft. The resulting box is shown below. I’ll drawn the circuit up, & post it on here, with a description of its operation; in case there is someone on here that wants to replicate it. Cheers Banjo
  25. I read a couple of stories on the web, regarding some people poorly fitting trigger wheels to engines, where the results have been catastrophic. It led me to research the use of a harmonic balancers, in general, & on K series engines. https://en.wikipedia.org/wiki/Harmonic_damper Torsional twisting, flexing, & vibration are typically more common in long crankshafts, such as are found in straight six & eight cylinder engines. It occurred to me, that our little K series engine did not fall into that category, so why did Toyota feel the need to fit a harmonic balancer. The K series engine, also has a main bearing on the crankshaft between each & every cylinder, so should theoretically, be pretty safe. Bearing in mind that 1200cc K Series engines, were successfully used in midget dirt track racing cars in previous decades, at rev limits at least twice what they were designed, would I have thought; proven them almost unbreakable. In fact, I believed the only K Series engine that was fitted with a harmonic balancer, was the 5K; however, I have since discovered that there were some 4K engines that came out with harmonic balancers fitted, & I presume the 7K had them also. Even the very simple & small crankshaft pulley fitted on the 3K engine, were balanced at the factory, as the few I have on the shelf here, all have 1, 2, or 3 balancing drillings on the rear of the pulley. The crankshaft pulleys on the 3K & 4K, were also quite small in diameter, compared to the much larger diameter, fitted to the 5K. When fitting a trigger wheel, to the crankshaft pully, the bigger the diameter, & the more trigger teeth; & the faster the ECU can respond to crankshaft rotational speed changes. The problem appears to be, that the trigger wheels themselves are not balanced, & in many cases, the reason the trigger wheel, failed; was because it was attached; (even welded), to the outer harmonic balancer pulley itself. It was for this exact reason, that I made my trigger wheel 150mm in diameter, which is only a little bigger in diameter, than the 5K pulley outer diameter. That also accommodated a 36-1 configuration, & still left sufficient distance between the rare earth magnets, to obtain very clear switching transitions, which I have checked on my oscilloscope. It is also, one of the reasons, why I made my trigger when out of aluminium, rather than steel. I have a similar sized steel trigger wheel, which I bought on line, & it weighs 550gm (over half a kilo). By comparison, the aluminium trigger wheel, also 6mm thick, like the steel one; weighs just 200 gm. The other issue that makes the steel trigger wheel an issue, is that the majority of trigger wheels have either one or two missing teeth, at one position. The lack of two teeth; naturally create an imbalance, but most trigger wheel manufacturers, simply drill a hole in the trigger wheel, close to the outside; exactly opposite the missing tooth/teeth, to compensate. Because my aluminium trigger disk, does not use teeth at all, the only imbalance would be one 4mm x 5mm rare earth magnet, whose weight is tiny. I can easily drill, at 180 deg., to compensate, for the missing magnet, or just not drill out one hole. I also took care, in ensuring that the trigger wheel/disk, was only attached physically, to the crankshaft pulley “centre piece"; & spaced off the centre piece, so it cleared the pulley grove section of the harmonic balancer. The real beauty of using aluminium wheel, & the tiny rare earth magnets, is that you aren’t confined to using the traditional VR (variable reluctance) sensors, whose output signal needs conditioning; before it can be used reliably, by the ECU. The only disadvantage I can envisage using magnets; is that they may attract, iron filings, to attach to the disk. Might be an issue, if you plan on driving your Rolla around the Pilbara area of W.A., but should not be an issue on sealed roads. The worst case scenario, would probably require a little fixed brush in place to keep the face of the trigger wheel free of debris. Cheers Banjo
×
×
  • Create New...