Author Topic: Ignition Box  (Read 2141 times)

Offline cfellows

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Ignition Box
« on: February 18, 2014, 12:39:59 AM »
I've started work on the Ignition Box.  It was mostly already assembled for my Odds n Ends Hit n Miss engine.  I just had to add the aluminum angle piece to the back end, drill the holes and insert the terminals and insulator. 

Here is the switch end...



And here is the business end...



I will build a wooden enclosure and the assembly shown here will be a drawer that slides out so I can recharge the battery.

Chuck
So many projects, so little time...

Offline GordonL

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Re: Ignition Box
« Reply #1 on: February 18, 2014, 02:32:04 PM »
I did a similar box a long time ago with a gel battery and an automotive coil and capacitor. That way I know that at least the ignition works so I can concentrate on carburetor, timing etc. I can clean it up later once everything is working right.

Offline cfellows

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Re: Ignition Box
« Reply #2 on: February 19, 2014, 05:12:21 AM »
For the enclosure, I opted for utility over glamour.







It's made out of 3/8" thick MDF with several coats of Polyurethane so it'll be easier to wipe off oil and other stains that seem to go along with the hobby.  Overall dimensions are about 7.5" x 5.5" x 2.25".  The only thing left is to attach a small swinging latch so the drawer will stay closed.

Chuck
« Last Edit: February 19, 2014, 05:16:59 AM by cfellows »
So many projects, so little time...

Offline PStechPaul

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Re: Ignition Box
« Reply #3 on: February 22, 2014, 09:26:00 AM »
Does the coil just connect to a set of cam-operated mechanical points, or does it use a magnetic pickup or other electronic means? It may help to use a transistor to drive the coil and then create the spark precisely when the points open, without arcing, which can result in reduced power, lower voltage spark, and delay of sufficient spark to ignite the mixture. That may be why some engines have to have like 30+ degrees of spark advance, even at low speed. If you are interested I may be able to help,
 
Here is a circuit diagram and simulation:

Offline steamer

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Re: Ignition Box
« Reply #4 on: February 22, 2014, 10:30:33 AM »
Nice simulation!....we've had several engines with surprising amounts of advance....hmmm.


Thanks for that!   Lot's to think about.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

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Re: Ignition Box
« Reply #5 on: February 22, 2014, 10:34:21 AM »
Does the coil just connect to a set of cam-operated mechanical points, or does it use a magnetic pickup or other electronic means? It may help to use a transistor to drive the coil and then create the spark precisely when the points open, without arcing, which can result in reduced power, lower voltage spark, and delay of sufficient spark to ignite the mixture. That may be why some engines have to have like 30+ degrees of spark advance, even at low speed. If you are interested I may be able to help,
 
Here is a circuit diagram and simulation:


I might suggest you start a thread on your simulation, and perhaps solicit some schematics from the membership?....A bit of simulation on your part may solve many problems....or as the old saying goes...Most Carburetor problems are electrical in nature... 8)

I am sure I would benefit from it, as I'm not a "sparky"

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!