copperclad
Elite Veteran
Location: ..
| hi darwin
i believe the engines that use a magneto are fixed timing , and that they set the timing to be a compromize between a good top end and relatively easy to start , and the simplest of EI units are fixed timing too , and are set the same way
it is my understanding that timing advance EI units have a micro controller in them and it is relatively easy for it to measure the RPMs and set the timing accordingly , in this case they can optimize the high end and have the starting very easy , all the timing advance units i have setup have the signal magnet set 29 degrees before TDC , and i believe they retard the spark for starting and advance it as the speed increases
i know there are a few EI units that sell for under $30.00 US and i believe these are fixed timing , then it gets a little dicey as the $70.00 US units can be either way , when i order i am carefull to see that they are advertised as timing advance , and the units i have recieved were labeled timing advance , there are a mess of suppiers and they seem to come and go , one of the links i posted was showing them as available the day i posted the link and not the next , and one companey i thought was out of buisness is now advertising again
with a standard G-231 you can pull the coils and flywheel and knock off some weight , but you have to temper this with the weight of the EI unit and the second flight pack , every thing i have read says " DO NOT USE A SINGLE BATTERY FOR THE RX AND THE EI UNIT " and what is good is some of the EI units run at low amperage ( 500ma ) and will run off a lipo battery and in this case i believe there is a weight saving to be had
bottom line is that electronic ignition is not for everyone , a lot of people prefer magnetos and have no interest in EI , i have engines set up both ways , and i can say i spent some time with my first EI engine getting used to the ins and outs of it , now that i have flown and setup a few of them i am getting a lot more comfortable with them
HTH , dana 
[EDIT]
i got to thinking last night , that Zenoah issues different EI units in the US and Europe , it is my understanding that the Euro model will run on a single cell lipo , but the US version is 4.8 volts , i went back through the links above and see that most of these other US units are rated 4.8 to 6 volts , i know some EI equiped engines state they will work with a 2 cell lipo , so i am looking into whether a 3 volt system is available here in the US , and which units are rated to 8 volt plus for 2 cell lipo , i will post back here if i am able to find anything
http://www.apacheaviation.co.uk/Ign...on_systems.html
here is a link to a unit that is identical to my BMCA unit same case , same label and they list it as from 3.8 volt to 6 volt |
