Magneto Question

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jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Magneto Question

Post by jeff deringer » Fri Jan 10, 2020 3:03 pm

I have a Bosch DU4 Dual mag on a 1915 Overland that I'm almost done restoring. I’m pretty sure I left the mag set up exactly like it was pre-restoration when the car ran (great). The mag is unusual to me in that it has a terminal in the dead center of the cap that is/was fed by a coil. There was a modern 6V coil on it with a separate condenser which I changed to new parts just because. I am fairly certain that there never was a switch on the car to move from Magneto to Battery. It always just ran. Now that I’m on the home stretch with the car, everybody I ask says it has to have a switch on it to start on battery and then switch to mag. My dad had a 14 Overland with a typical DU4 for decades and he never touched the Splitdorf switch on the dash except to kill the engine. I have a 14 Overland with a typical DU4 that he restored that’s exactly the same way.

I am electrically challenged and confused by everything I read on the magneto subject, hi-tension/low-tension, it’s causing me tension! I’m looking for confirmation that the engine will start and run and the magneto will not be damaged by running it as it is set up, with the coil attached to the center of the DU4 Dual mag, and only an on/off switch in the control box on the steering column to turn the ignition on/off.

Thanks in advance for any help offered.
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alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Sat Jan 11, 2020 12:08 pm

Hello Jeff,
If you are happy with how your car runs and behaves, I would not mess with it. It appears that you are running your car on the points and coil and not on the magneto. That means that you are running as a car would out of the 40's, 50's and 60's. If you want to have the ability of running your car on the points to get it started then switching the circuit over to run on magneto, you will need to make sure your switching is correct for that application and that you magneto is in fact "hot". The DU4 dual is a great magneto as it is robust, has provision for a hot spark to start on coil and points, then when you RPM's are up, switch over to run magneto, (stopping the need for electricity). Can you post a short phone generated video post of your Overland starting and running?
Al

jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Re: Magneto Question

Post by jeff deringer » Sat Jan 11, 2020 12:52 pm

Al, thanks. I wish I could post a video but that is the problem. The car won’t start easily now due to possibly the ignition and/or carburetor issues. It will start if I pull start it, but I haven’t really got it running. It ran great years ago when I started so I left the engine alone, except for the carb. It was a Schebler R that leaked like a sieve. I got tired of fighting it and put a different one on. Never fired again. That’s the only carb I’ve seen that will fit due to conflict with the steering box, which was moved to the left side in 15 with basically the same engine. I finally had an offset manifold made so I could put a trusty Zenith or Tillotson on it, but that’s as far as I got. The engine turns so slow even though I’ve paid (twice!) to have the starter rebuilt that it just doesn't seem to generate much spark. I just had a guy go through the mag and fix a couple things that were amiss and haven’t got it back on the car yet. This is where the whole conversation came up regarding switching between bat and mag.
I appreciate any advice or guidance I can get from the people here. I’m not nearly the mechanic that my dad was, dang it!!

alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Sat Jan 11, 2020 1:25 pm

Hello Jeff,
If you have paid twice to get your starter rebuilt and it still cranks awfully slow, I would check out your battery cables and make sure they are not corroded. You may not be getting full voltage and current from the battery to the starter. I will confirm, if all the twist from your battery is being consumed just rolling over the engine, you do not have much left for a hot spark that is needed to fire your engine. That would be the first thing I would sort out. Next, I would get serious about the carburetor. Even if you get a good spark at the right time but do not have fuel at the right amount, it will not run. Simple as that! Or run very poorly. Could you post a good picture of the carb. side of your engine so we can see how limited your space is? Actually that is a problem we all deal with on these antique automobiles. My Locomcobile, spoken about elsewhere on this forum, has a similar space limit issue that I have finally got a good resolution for. Lets get your Overland up and running!
Al

jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Re: Magneto Question

Post by jeff deringer » Mon Jan 13, 2020 2:16 pm

Al,

Thanks for the help. During the time the mag has been off the car I made new cables from 2/0 copper, even though the existing ones weren't bad, they weren't as heavy duty. Since the mag is still off I haven't had a chance to try them, but good suggestion.

This weekend I think I discovered an answer to part of my issue on a piece of paper from the file for that car. It said "DU4 mag not hooked up". So it looks like you are correct, the car was only running on the battery, apparently only using the mag as a conduit for the points and basically a distributor. My question now is, what are the advantages of running the car on the magneto? I could add a switch but not sure it's necessary. This is where I get confused. Well, not the only place, but one of many!

I am attaching photos of the original Schebler carburetor and the modified intake set-up. I haven't been able to give the new set-up a fair chance to work due to several factors that aren't important. I apologize for the sideways photos. I can't seem to get them right!
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alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Mon Jan 13, 2020 4:22 pm

Hello Jeff,
Is your replacement carburetor a Zenith? One advantage for a magneto, but maybe not so much for your 1915 Overland, is the older cars didn't generally run a generator or good reliable electrical system that could keep a battery charged. Your Overland does have a generator so your system should keep your batter charged up and provide power to your coil, points and spark plugs. You have been running your car, in the past, with your magneto only functioning as a distributor. Your existing switch is just serving to break the circuit and then killing your points. Your switch would have to serve as a means to ground out your magneto to interrupt the spark from the mag. to the spark plugs, if you put your whole system back into service. I have a question for you. Could you post a picture of the front of your 1915 Overland radiator and measure the radiator core that you see from the front, then measure the height not including the fill port and the width from outside to outside. I have located, what I think is a 1915 Overland radiator, and would like to confirm what it is.
Regards,
Al

jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Re: Magneto Question

Post by jeff deringer » Wed Jan 15, 2020 12:50 pm

Al,
I will gladly measure the radiator, but I have been battling snow removal in the time I'm not at work. Will get it to you as soon as possible. Does the radiator have a little rectangular brass tag on the inside of it next to the neck that says something like Atwood or Atwater Kent, and stamped with a number 80-83? That tag is on all the Overland radiators I have.

Jeff

alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Fri Jan 17, 2020 9:32 am

Hello Jeff,
I certainly understand what you say about snow. You are probably getting hit head on today as we are getting hit by the bottom of the snow storm that is passing over today! When you get a chance to catch your breath share a few measurements from your 1915 Overland. Do you happen to have a spare radiator?
Al

jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Re: Magneto Question

Post by jeff deringer » Tue Jan 21, 2020 11:27 am

<t>Al,<br/>
<br/>
If the radiator had a shell looking form the front the exposed core from inside of shell to inside is 22 3/8” wide and 18" tall, ignoring the angles on the corner.<br/>
Looking at it from the back it measures 26" wide and 20 1/2" to the bottom of the tank.</t>
I don't know why the two photos get posted sideways but I can't fix seem to fix it.
Also, not sure what I was thinking on the radiator tag. It is indeed made by Willys Overland. The model number is stamped on the lower right corner of the tag.
I do have an extra radiator actually.
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alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Wed Jan 22, 2020 7:38 pm

Thanks for the measurements of your original Overland radiator. That will help...
Al

jeff deringer
Posts: 86
Joined: Thu Nov 11, 2010 6:56 pm
Location: Camas, Wa

Back to the Magneto

Post by jeff deringer » Thu Jan 23, 2020 11:25 am

Since I now know that my car was not running on the mag, how should it be wired?

*The coil would connect directly to the center of the mag.
*The power would connect to the positive side of the coil.
*The condenser would connect to the negative side of the coil.
*The negative side of the coil would connect to the cover of the points on the mag.
*The on/off switch on the steering column would connect to the same cover on the points of the mag.

Close?
Not close?
No hope?
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alsfarms
Posts: 410
Joined: Wed Sep 03, 2003 7:29 pm
Location: Deseret, Utah

Re: Magneto Question

Post by alsfarms » Thu Jan 23, 2020 4:15 pm

In response to your thoughts on wiring up the mag to only act as a distributor. I think you are very close, (without seeing the exact wiring). Your switch leg would be on the hot side and would simply act to break the circuit open to "kill" the engine. You should be able to test your wiring and see if you throw a spark to the spark plugs.
Al

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