ET: Engine (Twin) Programmable ignition

[Bill Cannon]

I believe a way to use the Harley ignition if you have a housing to mount it in is to modify a Buell Blast rotor cup by milling a slot for the second cylinder at the correct angle. I am not sure if the beginning or the end of the slot is the trigger event.

I have Bosch electronic system based on BMW airhead parts. This uses a Hall effect trigger and it is the leading edge of the "window" that initiates the spark.

Bill

 

[Nigel Spaxman]

A lot of people around Vancouver are using Harley type ignitions, either a screaming eagle one that is no longer available or the Dynatec 2000i. I have the Dynatec, I was able to fit the sensor inside the housing that was used previously for my Rita Ignition. I made my own cup with slots in the right spot for the 50 degree cylinder angle but it is also possible just to re program the timing on one of the cylinders and use the standard cup. The Rita ignition I had before, worked great but it puts a lot of power to the coils and only large metal encased coils can take the heat. If you use the Dyna ignition the little Dyna coil can fit under the cowl. You can do anything you would possibly need to do with the Dyna ignition. I have the vacuum operated switch hooked up. With the VOS you can run a bit more advance. When my bike is running down the road at light load at 3000 RPM the ignition timing will be about 36 degrees. When the throttle is opened a bit the timing drops down to 34 degrees. My bike is not that fussy about the timing anyway since the compression is only 8.1 to 1 but I think that the fuel economy increased a bit from ignition that was more or less fixed at 34 degrees with the Rita (at cruising speeds) I was able to hook the ignition to an old laptop computer to program different curves. I couldn't get it to work with my newer computer. I have the VOS hooked only to the rear cylinder which causes the switch to turn on and off rapidly at idle, I programmed both curves (the VOS on and Off curves) to be the same at idling speeds to prevent idling problems caused by this pulsing. Also I made an ignition curve that stabilizes the idle. The biggest advantage if you are using this ignition is you can get parts really easily in North America at Harley dealers.

 

[eglijim]

A lot of people around Vancouver are using Harley type ignitions, either a screaming eagle one that is no longer available or the Dynatec 2000i. I have the Dynatec, I was able to fit the sensor inside the housing that was used previously for my Rita Ignition. I made my own cup with slots in the right spot for the 50 degree cylinder angle but it is also possible just to re program the timing on one of the cylinders and use the standard cup. The Rita ignition I had before, worked great but it puts a lot of power to the coils and only large metal encased coils can take the heat. If you use the Dyna ignition the little Dyna coil can fit under the cowl. You can do anything you would possibly need to do with the Dyna ignition. I have the vacuum operated switch hooked up. With the VOS you can run a bit more advance. When my bike is running down the road at light load at 3000 RPM the ignition timing will be about 36 degrees. When the throttle is opened a bit the timing drops down to 34 degrees. My bike is not that fussy about the timing anyway since the compression is only 8.1 to 1 but I think that the fuel economy increased a bit from ignition that was more or less fixed at 34 degrees with the Rita (at cruising speeds) I was able to hook the ignition to an old laptop computer to program different curves. I couldn't get it to work with my newer computer. I have the VOS hooked only to the rear cylinder which causes the switch to turn on and off rapidly at idle, I programmed both curves (the VOS on and Off curves) to be the same at idling speeds to prevent idling problems caused by this pulsing. Also I made an ignition curve that stabilizes the idle. The biggest advantage if you are using this ignition is you can get parts really easily in North America at Harley dealers.

Thanks Nigel, this is the kind of info from existing users I was looking for, I am happy with the RITA on my road Egli at present but am seeking a programmable system for the 1250 big bore race engine. We had so many failures in the past that all of Ian Hamilton's Race bikes ran twin points with fixed timing (no atd) . Any idea of the power consumption of the 2000i ?.

 

[Robert Watson]

I ran a Lucas Rita for a while before I switched over to Harley bits. I made a new cup. The Lucas Rita drew a huge amount of power and like Nigel says anything less than the massive Lucas coils and they would burn out. I tried several different ones and always kept a spare. When I switched to the Harley stuff the power consumption virtually disappeared. This is because it only draws power when the hall effect window is open. If the power supply is wired downstream from the ammeter you can watch the needle flick at the ignition points. This is a big bonus if you are a short throw long throw fan (atic) when starting the beast!
I have no idea where the ignition fires..... I set it up statically when I put it together (about the early to mid 90's) and recall advancing it until I could make it detonate, then turned it back a bit. I run the VOCS on both carbs and also wired an idiot light on the switch so I can tell when the vacuum switches the advance curve. That switch is adjustable. The ignition just works. Day in. Day out. I run NGK BPR7ES spark plugs and I think in the last 20 plus years I have changed them, maybe twice. I know I put new ones in in 2007 before going to Australia. And, like Nigel said, parts all over the world. Not that I have needed any - touch wood.

 

[Michael Vane-Hunt]

Nigel. How many inches of mercury did you set your VOES to switch on? I run mine at 4 on the twin and John said I should use 2 on the Comet. I expect there will soon be a long line, at your door, of us Harley ignition users. Mike.

 

[Nigel Spaxman]

We have in the past used various bits from Dynatek and am generally happy with the Lucas RITA on my road Egli. The problems start when you need to move the plot to suit Kickstart or Electric starter, Twin plugs and the different max advance needed for different fuels or bored and stroked engines.
The thrust of my enquiry is why seek to re invent the wheel when it seems all of the above is readily available without going down the one off route. The Dynatek 2000i ( other suppliers are available with the software at no cost)kit for Harleys'. My understanding is that this lets the user move the advance for the rear cylinder by +- 10 degrees. When we did some dyno work on my 1150 Egli 20 years ago the engine was sensitive to a changes of advance of 2 or 3 degrees so 5 degrees off on the rear or both off by 2/3 degrees would be unacceptable . These ignitions,( Glenn Bewley has a Rapide fitted with the Harley/John Mcdougall version) look as though they happily fit into one of the available magneto replacement castings or maybe one of the old Dolphin twin points mountings. Complete kits are available for well under £150 via ebay or direct from dealers which makes the cost of some other systems nonsense. Would like to know if any are in use and their power consumptions ?

The dyna uses a lot less power. Probably the power used is about 25% of the Rita

 

[Cyborg]

According to the man at PA, my ignition draws 34 milliamps and the coil draws approximately 4 amps when on. (time of saturation or dwell period.)

 

[Oldhaven]

To add to Cyborg's comment, if you look at the maps at post #5 the coil on period is programmed to compensate for RPM. The system also has an automatic coil shutoff to prevent coil overheat and draining power.

 

[Nigel Spaxman]

Mike I have never checked to find out at what vacuum level my VOS grounds. I realize I might be able to benefit by adjusting that and I have talked to Robert about it, but to begin with I have assumed that having it set as it comes which must be right for the Harley engines is probably good enough. My engine never has the slightest tendency to ping. I tend to run the 94 gas almost always though because I prefer not to have Ethanol in my gas. The odd time when I ran it o 87 it hardly seemed to make any difference. That leads me to believe that I could have the VOS ground at a bit lower vacuum and it would still be OK. That way even at the higher cruising speed and moderate acceleration it would still remain at full advance. Robert installed a light so he would know when his VOC was grounding, that way he could discover when it was actually working during normal riding. I haven't even had time to instal this light, I have had so many more important things to do with my bike.

 

[Michael Vane-Hunt]

Thanks Nigel. The VOES come set at 4 Hg. I test them before installing as the last one I put on did not close the circuit at any amount of vacuum. I like the idea of a light in the circuit. I will have to check out Robert's set up. He is much too clever. My bike pinged a bit but I just kept adjusting the sensor plate a miniscule amount until pinging stopped at all speeds, all elevations and on any gas I could get when traveling across the USA last few years. I tried to get good gas when I could but to be honest I could discern little difference in performance what ever gas I used. Some had up to 15% ethanol and some stations on the back roads looked as if they only got fresh gas once every few months.