Reply to Cilff Ducharme [not private]

[ARTHUR OKUN]

You wrote: 
>
>Cliff Ducharme and any one else
>
>Cliff, I could not seem to make your Email address work and am 
replying 
>here.
>
>I have built a number of sucessful aircraft ignition systems and am 
about 
>to build an injection system.  Aircraft  concerns and needs are so 
>different from the others on DIY_EFI that it is a different world.  It 
is 
>reassuring to see that someone else is concerned with aircraft 
engines.
>
>The system is base on GM DIS hardware (distrbutorless ignition 
>system).  I figure that if GM will build a base and coil system that 
works 
>and controls so nicely that there is little reason to reinvent that 
part of the 
>system.  The GM hardware uses a bunch of power, but works down to 9V 
>or less.  This allows the cars to start on cold mornings when the 
system 
>voltage is pulled down from heavy cranking.
>
>My controller based on Signetics' 8X550 processor.  This 8031 
>derivitive is plenty fast and has sufficient AD input to process every 
input 
>I care about.  I use a Harris automotive part in the controller to 
watch for 
>pre igniton and dentonation.
>
>The the system uses a timing disk mounted behind the prop for timing.  
I 
>keep one magneto functional for a backup.  At present spark timing is 
a 
>calculated function of  MAP and RPM.  There is no mapping and the 
>calculations can be modified easily.  The timing is dropped back if 
>preignition is sensed and all advance drops out if the engine over 
revs.
>
>Various operational parameters are output to a four line by 20 
character 
>LCD.  The data is also continuously dumped to a serial port.  Several 
>reassignable buttons can be used to change the operation in service.
>
>This system would great job of running your lawn mower.  The GM 
>module will work fine with just one coil installed.  You could get to 
work on 
>the fuel injection and forget the ignition and controller development.
>
>I have some ideas, developed over a considerable period of time, about 

>how an aircraft efi should work.  I really want to work on the 
injection 
>system but find myself short of time. 
>
> 
>Would you want or appreciate more discussion? 
>What are your goals for the system your are developing?
>What are your hardware and software skills?
>What test facility do you have available?
>
>I am an EE, '70 with too much to do.  I am good at prototypes and 
>machine work.  I have experimental catagory aircraft available for 
testing 
>and my friends are also pilots who have become sympathetic to testing  

>equipment.
>
>I prefer 8031 type controllers.  My software is a set of assembler 
>modules tied together with compiled basic for the IO to the LCD and 
>serial port.  Ignition management takes up about 15 percent of the 
>controllers time at 3000 rpm.  The controller is running at 12E6 now.  
It 
>could be pushed to 16 MHz easily.
>
>John Carroll
>307 674-8469
>fax   674-4510
>
>
>
>
>--UAA25219.812858672/wave.sheridan.wy.us--
>
>
>
>
i use to be involved with light planes and are familar with
bendix type magneto ignition "ie impulse couplings ,starting vibrators
dual ignition and etc  

a company called slick magneto tried to certify a cap discharge
electronic system and was turned down by the faa

also the popular bendix mechanical fuel injection system always 
requires injector cleaning and the fuel servo costs a fortune
to overhaul carbs require little maint but are prone to venturi
icing   "one big barrel"
the faa seems to like things that donot require electrical power to run
that are critical to powerplant operation but there should be no probs
on an experimental cat. air craft
thats it for now  

ps. iam finished discussing spark plugs until asked for info
bye