Topic: ignition resistor


oldford2    -- 12-25-2013 @ 5:06 PM
  Some guys have installed a spring loaded toggle that bypasses the resistor when starting. That way the full voltage is sent to the coil instead of approx 4 1/2 volts through the resistor.
Now my question is when does the resistor reduce voltage: immediately or a slight delay till it "heats" up? What does Bob (Supereal) think about this bypass toggle? Sounds like a good idea but...
Thanks
John

This message was edited by oldford2 on 12-25-13 @ 5:11 PM


ford38v8    -- 12-25-2013 @ 8:37 PM
  John, The reason for the bypass is because the starter robs too much voltage away from the coil. Have you ever witnessed a car that you can crank and crank, and it won't start until the instant you let up on the starter? That's the whole reason right there.

I thin k I can answer for Bob on this. Bob has installed a diode between a hot wire from starter solenoid to coil, thereby eliminating the momentary switch you describe. They both do the same job, but his installation offers an automatic fail safe, as your momentary switch requires you to actually think about what you're doing.

The resistor doesn't delay as it heats up, it is operational the instant you turn on the ignition. What it does do, however, is allow less voltage through to the coil when full voltage is available to it, and more when less is avaialable to it. It does this by heating up or cooling down as the available voltage changes. A hot resistor being more effective at its job is the key to its success.

Alan


oldford2    -- 12-26-2013 @ 4:28 AM
  Alan,
Thanks for the clear explanation. I like the diode idea. I wonder why Henry didn't think of it? Maybe there is a downside? Hey, Bob, what is the spec on the diode?
Thanks again.
John


ronnie    -- 12-26-2013 @ 5:49 AM
  the diode in the ignition works great.The only downside is
You have to unhook wire if you need to "bump" engine
Over for any reason. also if you accidentally hit starter
Button while in gear,it can cause car to lunge forward.

Ronnie


ford38v8    -- 12-26-2013 @ 9:05 AM
  Ronnie has a good point. For me, I think reason enough to not use the diode and go with the manual push button as oldford2 describes.

Here's Bob's diode:

OK, it won't load up for some reason. You'll have to wait for Bob to upload it.



Alan

This message was edited by ford38v8 on 12-26-13 @ 9:11 AM


supereal    -- 12-26-2013 @ 8:38 PM
  I have been installing the diode bypass for years. If you need to "bump" the starter for some reason, just take the wire off the coil. The rating of the diode is not important, as it bypasses the circuit, and doesn't carry the full ignition current. We use the "top hat" type readily available at Radio Shack or other supplier. If anyone wants the page on installation, I'll post it again. Thanks to my friend Alan and others. Bob S.


TomO    -- 12-27-2013 @ 10:38 AM
  If your starting circuit is in good condition, you do not need the diode or bypass switch.

Make sure that you have 6 volt cables from the battery to the solenoid and then to the starter. Make sure that you have 6 volt ground cables from the battery to the body and from the body to the motor. Your starter should turn over the engine easily and you will have sufficient voltage at the coil to fire the plugs.

Your coil should also produce a 1/2" spark while idling and the engine at operating temperature.

Tom


supereal    -- 12-27-2013 @ 5:53 PM
  I agree with Tom, but my diode circuit is meant to compensate for less than systems in top conditions. Many old car enthusiasts are not mechanics, but want reliable starting, hot or cold. The diode is not meant to replace worn or weak components, but allow enjoyment of a vehicle that might otherwise be abandoned.


oldford2    -- 12-27-2013 @ 6:36 PM
  Thanks Bob,
If you could post the diode diagram again I would appreciate it. Maybe the diode spec.
John


murphy1936    -- 12-29-2013 @ 8:05 AM
  It would be nice to have the info on diode just in case you feel old like me 80, and can't get around good enough to make things 100 %. John
P.s can't open above infor page not available for some reason
Super Deluxe 41

This message was edited by murphy1936 on 12-29-13 @ 8:07 AM


supereal    -- 12-29-2013 @ 11:56 AM
  I am posting the diode page. It isn't designed for purists, but for the hobbyist who wants better starting without having to seek professional help.


joe b    -- 12-29-2013 @ 3:00 PM
  Super Would you please list a supplier and part number for the diode?


supereal    -- 12-29-2013 @ 4:13 PM
  I just picked them out of my junk box. I was the chief engineer for a broadcast company in an earlier life. Radio Shack has them, as do other consumer outlets. In this configuration, they handle very small current, as the are paralleled with the stock resistor. I design lots of stuff, and haven't had a "top hat" blow yet.


supereal    -- 12-29-2013 @ 4:14 PM
  I just picked them out of my junk box. I was the chief engineer for a broadcast company in an earlier life. Radio Shack has them, as do other consumer outlets. In this configuration, they handle very small current, as the are paralleled with the stock resistor. I design lots of stuff, and haven't had a "top hat" blow yet.


supereal    -- 12-29-2013 @ 4:15 PM
  I just picked them out of my junk box. I was the chief engineer for a broadcast company in an earlier life. Radio Shack has them, as do other consumer outlets. In this configuration, they handle very small current, as the are paralleled with the stock resistor. I design lots of stuff, and haven't had a "top hat" blow yet.


EFV-8 Club Forum : https://www.earlyfordv8.org/forum
Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=6852