Banjo

Hi Jasper, I've always found the response for the MAP sensor is better directly off the inlet manifold, than from the port on the Aisin carby. I've only ever connected it the vacuum line to one inlet runner, & never had a pulsing issue. You can dampen out any pulsing, a bit, by narrowing the hose at one point, or inserting a bit of metal tube in the vacuum rubber line, which will create a small length of line with a small ID. Looking forward to your thoughts on the Back Box, when you get it. Cheers Banjo

Hi Jasper, Had a look around the net yesterday, & can't find anything adverse about the Black Box unit. The Utube videos seem to indicate it is quite simple to install, & well thought out. If you want to bite the bullet, I'd be very pleased to hear your assessment of it, once you get it. There is another Australian one, called Speeduino, but it is a kit & you have to assemble it, & put it in an enclosure. It does work with a very good software system, from EFI Analytics. I've built the Speeduino, & have had it running on the bench, with the software, but not fitted it to my daily drive as yet. Cheers Banjo

Not a silly question. Yes, slackening off the 12mm bolt, & turning the dizzy slightly will do the exact same thing. I'm just lazy, & don't want to get my tools out, if it is at all possible ! Let me do a little more research tomorrow, on the Black Box unit, & see if I can find any downside to its use, that may be reported on auto forums, before you order same. Actually came across a video this afternoon, of an Aussie, who fitted one on is olde skool Holden, & was having some issues. https://www.youtube.com/watch?reload=9&v=YjGOmkZH1hc https://www.youtube.com/watch?v=rXhCcHPi7p4 Cheers Banjo

Love it Mate ! Great pictures ! I nearly split my cornflakes out whist reading that caption ! I'm a bit worried about those ramps you used to get the Hi-Ace on the back ? Lovely selection of cars there. My late brother had Hillman like that ! Good heavens ! Chrysler, Hillman, MG, BMW, Rolla, Foulcan, Volvo, Merc, Landy, I can't see two vehicles from the same stable. Does your club have a rule, one of each, or something ? I'd give you more than one (1) if this website allowed it. Cheers Banjo

Hooks up to points / Optical / or Hall Effect sensors, like the Accuspark. They hook it up to a VW engine with simple points. Have a look at Utube video. https://www.youtube.com/watch?v=7qv87mFw6T4 I want one of their engine dyno setups in my garage ! Here is another video you might enjoy, on subject ! https://www.youtube.com/watch?v=jtfrlUyhaH4 Cheers Banjo

I came across the Black Box programmable ignition recently, out of the USA, which is very like the Silicon Chip / Jaycar unit, in terms of features. However, the Black Box, can apparently program the advance map/curve using a supplied software program, which is a big benefit, over the Silicon Chip unit. The Silicon Chip unit, requires a hand control kit, which are almost non existent now. The Jaycar unit is slow to program with a 15 x 15 advance map. The Black Box one has 21 x 21 map, which provides more resolution, in both axes. Has anyone on Rollaclub ever used or had any experience with the Black Box unit ? Another advantage is the Black Box unit is not a kit. It works right out of the box. Would be keen to hear from anyone. https://www.cbperformance.com/CB-s-Black-Box-Programmable-Timing-Control-Module-p/2013.htm Cheers Banjo P.S. There a couple of handy free calculators on the above website, under "Support" for engine & gearbox ratios.

Thanks for the endorsement Graeme ! Like you, once I put it in, I never touched it again. Jasper, the cheaper option would always be to modify your existing Bosch 4K dizzy, and add the Accuspark. I like the Denso 3K dizzy for two reasons. 1. They are physically, the smallest of all the K Series dizzies available. 2. To my knowledge, none of the other Denso's or Bosch K series dizzies had the Octane adjuster on them. The reason I like the Octane setting is two fold. You can tweak the initial idling static advance, without changing all the ECU map. With the Accuspark, if your ECU was to die on you, you can run on the Accuspark only, as the ignitor can handle a coil with > 1.4 ohm primary impedance (resistance). Now you won't have any auto advance or vacuum retard, but it will allow you to " limp" home. (I've actually tried it) The Octane setting allows you to screw the advance up to a setting much higher than static. P.S. The other reason you might want to retain your original dizzy, & get another one, that you can modify, is that you can carry the old one around in the boot, & if all else fails miserably, you can swap dizzies over on the side of the road, & get safely home. All you need in addition, in the boot, is a 12mm & 19mm ring spanners. I was never a boy scout, but I am always prepared. Have never ever been towed home or left stranded in my whole life, in any of my Rollas. Cheers Banjo

Hi Jasper, I would strongly suggest, if you are going to head into programmable ignition, that you seriously consider another kind of trigger, rather than just using points. Points really suck, when used in this precise application. The rubbing block wears, & the cam lobes in the dizzy wear, providing slightly different timing for each trigger. Oh, & they have a habit of bouncing/oscillating at high revs. On top of that, you have to keep the points "wet", by passing a reasonable current through them. Not enough to arc, but enough to get a good clean signal. >100mA. The reason for this, is to "burn off" the very thin film of oil vapour that builds up inside the dizzy, & on the points contact surfaces. I would strongly advise using a non contact system, such as the Accuspark, or maybe a K Series electronic dizzy with VR sensor, as Dave has suggested. The only trouble with VR electronic dizzies is, that their output is dependent on RPM, and when you are cranking, the output of the trigger, is at it's lowest. VR sensor wires are also polarised. Does not work very well, if wired in reverse. There are two kinds of K Series electronic dizzies. Those with VR sensor only, & those with a VR sensor plus an in-built electronic ignitor. The model with built-in electronic ignitor is the better one, as you simply connect the output wire to a 100 ohm, 10 Watt resistor, the other end of which is connected to +12V ignition circuit. You then get a nice square 12 volt trigger pulse out of the dizzy, to feed to your ECU. Even if you can get hold of a K Series dizzy with VR sensor, but no built-in ignitor, you can grab a Bosch BIM024 module, as Dave has suggested, & attach the above mentioned 100 ohm resistor to the BIM024 coil connections. I ran one of those for several years, without issues. The advantage of the Accuspark is, that being a Hall Effect device, it gives the same output amplitude, irrespective of the RPM. All electronic programmable ignition systems, needs a MAP sensor, so you can dispense with the vacuum advance/retard device. However, you will need to dissemble the dizzy, & remove all the bob weights & springs, & then lock the shafts up, so all advance & retard, comes from the programmable ECU. The dizzy, then becomes simply a trigger device, & distributor of the HV to each spark plug. The Accuspark has another advantage, as you can use it directly to get the engine started, & then switch automatically to programmable ECU, as soon as the ignition key comes back to the "run" position. The very best K series dizzy, that I found, to create a source for electronic trigger pulses, is the 3K Denso model, with the Octane adjuster knob. This dizzy is the physically smallest of the K series dizzies. Accuspark do a module for it specifically. They are very easy to "lock up", & remove the vacuum advance unit. I actually made one up for an experiment a week ago. Took me all of 1 hour. 3mm roll pin was all I needed. Hope that assists your decision. Let us know how you are going to trigger the ECU, then I'll give you suggested options for ECU. Cheers Banjo

Hi Jasper, May be able to help you out there, but need to know a bit more about the engine you are going to fit it to. What model engine is it ? Has it been modified or upgraded in performance in any way. What model dissy does it currently have fitted ? 3K, 4K, 5K, 7K ? Does it have an octane manual adjuster knob on it ? Is the dissy in reasonable condition, in regard to bushes etc. ? Fire us off some answers to these queries & I'll put a solution suggestion up here later today. Cheers Banjo

You are so right. kHz is slow, relatively. The microprocessor handling all the counting & switching is running at 32MHz. The only limit is the sensors themselves. That's why I use Hall Effect sensors, as they have the ability to switch very quickly, & produce nice clean square wave pulses. Here are the ones I am using for trigger & synch pulses, off ebay. They are built into a threaded tube, so are very easy to install & adjust the distance between the "blue" tip & the rare earth magnet. Believe it or not, these are about $ 4.00 ea. delivered, stocked in Australia. Better still are the specs. It can switch at 320 kHz, which means it could handle the 106 flywheel teeth counting application up to 18,000 rpm ! All good ! Cheers Banjo

Distributor Rotor Arc Just doing some calculations on where to allow the ECU output to switch on each COP, with their own inbuilt ignitor. My 5K flywheel has 106 teeth on the flywheel, so there are effectively 212 teeth being counted over 2 revolutions, which is a full 4 stroke cycle. As 212 teeth span a rotational angle of 720 degrees (2 revolutions) the distance between teeth of each count is 720 / 212 = 3.396 degrees. So the synch pulse is generated, & that starts an 8 bit counter (can only count up to 255), to start counting from zero, and at count number, say 22, Cylinder no: 1 is at TDC. The second cylinder to be at TDC will be no: 3, which 180 degrees further on in rotation. The 8 bit count at that time will read 75, ([180/3.396] + 22). Cylinder no: 4, will be the next one at TDC, which again is 180 degrees further on in rotation. The 8 bit count at that time will read 128, ([180/3.396] + 75). The last cylinder to be at TDC will be no: 2, which again is 180 degrees further on in rotation. The 8 bit count at that time will read 181, ([180/3.396] + 128). At a count of 212, a full cycle is completed, & the counter can be reset, & it will then await the sync pulse again, to repeat the full cycle count gain. So I want an "arc" or period of rotation, where a cylinder can be fired, anywhere between TDC & back to a point lets say 40 degrees BTDC. Most K Series distributors, limit the advance to about 35 degrees. So lets be generous and allow a cylinder to fire anywhere between say 50 degrees BTDC & say 10 degrees ATDC. That is an arc or period, of 60 degrees of rotation, during which the spark plug can be fired. This got me thinking, as the arc on the end of the rotor in the distributor is made that way, for the same reason, so the tiny gap between the end of the rotor contact & the post in the distributor cap are always opposite each other, throughout the entire advance period. However, the arc on the rotors I have here don’t appear visually, to be anywhere near 50-60 degrees ? So I collected about 3 or 4 rotors in my box, from 3K, 4K, & 5K distributors, and all arcs were exactly the same, when I held them against each other, back to back. So I decided to measure up a rotor, & determine what angle or arc, the rotor actually was. The picture below was a 1:1 drawing I made. The angle was then measured with a protractor at 35 degrees. Then the penny dropped ! The distributor rotates at half the speed of the crankshaft, so every degree of distributor rotation is actually 2 degrees of crankshaft rotation. All degrees for BTDC & ATDC are in crankshaft degrees. Therefore the 35 degree arc of the rotor end contact, is actually 70 degrees of crankshaft rotation. So my 60 degrees allowance, which I thought was generous, is not even as great as what Toyota designed all those years ago. Maybe there was a bit extra in there for “tolerances”. So now with that 60 degrees nominated, that translates into a count of (60/3.396) = 17.67 say 18 counts. From the above calculations at an assumed count of 22 before TDC of no: 1 cylinder, we can set the limits of firing for each cylinder, in counts. From the above calculations, we have already the counts for TDC of each cylinder. TDC no: 1 = 22 TDC no: 3 = 75 TDC no: 4 = 128 TDC no: 2 = 181 So the count for the beginning of the allowed firing period, is each of those TDC count numbers, less 50 degrees which equates to (50/3.396) = 14.72 (say 15) The count for the end of the allowed firing period is each of those TDC numbers, plus 10 degrees, which equates to (10/3.396) = 2.945 (say 3) So now we have a set of counts based on flywheel position, for a particular synch pulse position, prior to & after the TDC positions of each cylinder. They are . . . Cylinder No: 1 Start of firing period 50 degrees BTDC = 22 – 15 = 7 counts TDC = 22 counts End of firing period 10 degrees ATDC = 22 + 3 = 25 counts Cylinder No: 3 Start of firing period 50 degrees BTDC = 75 – 15 = 60 counts TDC = 75 counts End of firing period 10 degrees ATDC = 75 + 3 = 78 counts Cylinder No: 4 Start of firing period 50 degrees BTDC = 128 – 15 = 113 counts TDC = 128 counts End of firing period 10 degrees ATDC = 128 + 3 = 131 counts Cylinder No: 2 Start of firing period 50 degrees BTDC = 181 – 15 = 166 counts TDC =181 counts End of firing period 10 degrees ATDC = 181 + 3 = 184 counts So the count of 184, is well before the end of the 212 tooth of the flywheel. 212 -184, means there are 28 counts, or (28 x 3.396) = 95 degrees of crankshaft rotation left. This will help us determine what the design limits are. as to how far before the beginning of the first firing period, the synch pulse can physically be. We can just take all 12 points we have calculated in counts, and move them backwards or forwards in rotation around the flywheel by adding or subtracting a particular count (angle) to every count number listed. So lets work backwards. We know the last count on the flywheel is 212, because that is how many teeth there are. Lets say we reset the counter on count 210. Lets say the last count for the "switch off" the cylinder no: 2 is 208 counts. As our calculation above was 184, that is effectively rotating everything (208–184 = 24) counts, or (24 x 3.396) = 82 degrees. So our new set of switching points are as follows by simply adding a count of 24 to each previously calculated number. Cylinder No: 1 Start of firing period 50 degrees BTDC = 46 – 15 = 31 counts TDC = 46 counts End of firing period 10 degrees ATDC = 46 + 3 = 49 counts Cylinder No: 3 Start of firing period 50 degrees BTDC = 99 – 15 = 84 counts TDC = 99 counts End of firing period 10 degrees ATDC = 99 + 3 = 102 counts Cylinder No: 4 Start of firing period 50 degrees BTDC = 152 – 15 = 137ounts TDC = 152 counts End of firing period 10 degrees ATDC = 152 + 3 = 155 counts Cylinder No: 2 Start of firing period 50 degrees BTDC = 205 – 15 = 190 counts TDC =205 counts End of firing period 10 degrees ATDC = 205 + 3 = 208 counts So the earliest that the synch pulse could physically be located is 30 counts, (lets say 28), before the earliest possible firing of cylinder no: 1 (50 degrees BTDC). A count of 28 correlates to ([46 - 28] x 3.396) = 61 degrees BTDC no: 1. This is ample room to achieve a result from any physical position of the synch pulse relative to the first cylinder to be fired thereafter. So off to do some programming now, & then attach the CRO oscilloscope & see if the theory all works out in practise. As I have a timing light, I can trigger it from any of these individual 8 points, I have noted above ( 31, 49, 84, 102, 137, 155, 190, 208 counts), & see what the degree wheel on the flywheel actually reads. Cheers Banjo

Nearly there ! The logic is that once the synch pulse is noted by the ECU, it indicates to the ECU, that the very next "trigger signal", (derived from the crankshaft trigger sensor) will be to fire at BTDC No: 1 cylinder. The next three (3) following trigger pulses must be 3 - 4 - 2, as that is the firing order. With the COP system, where we have a separate ignition ignitor/coil per cylinder, it doesn't really matter if the synch pulse comes along before another cylinder, as each ECU cylinder ignitor output lead can be allocated/wired permanently to any particular COP. If the synch pulse happens to be located before cylinder No: 2, then it will fire cylinder number 2, and the next three (3) pulses must be for 1 - 3 - 4 in that order. If the synch pulse happens to be located before cylinder No: 3, then it will fire cylinder number 3, and the next three (3) pulses must be for 4 - 2 - 1 in that order. If the synch pulse happens to be located before cylinder No: 4, then it will fire cylinder number 4, and the next three (3) pulses must be for 2 - 1 - 3 in that order. I've also used a similar technique when replacing a dissy on a K series, without going through the whole process of determining when the crankshaft pulley mark lines up with the zero mark on the timing chain cover; is either TDC no: 1 or TDC no: 4 ? I simply line the marks up without determining above. Put the leads on the dissy cap in the standard rotation position. You have a 50:50 chance of getting it right the first time. If it back fires when you try to start it, then just "swap" the leads directly opposite each other, on the dissy cap, & it will start. Great when you are working in the dark. Cheers Banjo

Hi Michalis, Plenty of videos on the internet, on how to do this, but is a lot of work to get it right. A quick way is to remove the orange & red plastic lenses, & clean them thoroughly inside & out, then paint them on the inside with special spray paints for plastics, for plastic tail-lights. A bit of research should find it for you. I did it like that, years & years ago, & it worked fine. Cheers Banjo.

You are correct, but a commercial tachometer is internally "scaled to count" 2, 3, or 4 pulses per revolution of the crankshaft, if they are 4, 6, or 8 cylinder engines respectively. Think of it this way. The turns ratio between camshaft & distributor is 1:1. It takes 1 turn of the dizzy/camshaft, to produce 4 pulses at the coil -ve terminal. If the pulse is derived from the fuel pump lobe, it takes 4 turns of the camshaft, to produce 4 pulses, from my synch pulser. Therefore, the tacho would display a rpm 1/4 of what it actually is, if using a tacho that would normally be fed a signal from the coil.

I also had to think about that one ! Most commercial auto tachometers are impulse type, & pickup the pulsing signal, derived from the collapsing field of the ignition coil. This pickup point is usually the negative side of the coil, although in modern cars with an ECU, this signal might come directly from the ECU. Depending on whether your engine is 4, 6, or 8 cylinders, the number of pulses created in 2 revolutions of the crankshaft, is therefore 4, 6, or 8 pulses. All multipurpose commercial tachos, usually have a "cylinder selection switch" on the rear, so the meter can be scaled appropriately. In our 4 cylinder Rollas, the points open & close 4 times, for each rotation of the distributor, which is 1:1 ratio with the camshaft. As the fuel pump lobe only "opens & closes" once per camshaft revolution, then 4 "distributor points" operations would have occurred in the same period of time. As the tacho I hook my synch pulser up to, would only receive 1 pulse instead of 4, in the same time period, I would expect the rpm, to be 1/4 of what the engine rpm actually is. If I've got that wrong somehow, I'll soon find out, as soon as I hook it up. Cheers Banjo