12 volt ignition with 6 volt system

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
kansasplowboy
Posts: 8
Joined: Sun Dec 01, 2019 4:00 pm
First Name: Randy
Last Name: Braddock
* REQUIRED* Type and Year of Model Ts owned: 26 RPU
Location: SW Kansas

12 volt ignition with 6 volt system

Post by kansasplowboy » Wed Nov 10, 2021 10:17 pm

My 26 project came with a 12 volt pertronix in the distributor but I would love to run the rest of the car on 6 volt to protect the starter. Is this even remotely possible?

User avatar

Craig Leach
Posts: 1906
Joined: Tue Jan 08, 2019 12:22 am
First Name: craig
Last Name: leach
* REQUIRED* Type and Year of Model Ts owned: 1919 Firetruck/1922 Speedster
Location: Laveen Az

Re: 12 volt ignition with 6 volt system

Post by Craig Leach » Wed Nov 10, 2021 11:21 pm

Randy,
Pertronics makes a 6 volt negative ground unit for VW distributers depending on whitch distributer you have. I think the unit for a 009 is 1845N6 but I don't know what distributer you have. Check the VW web pages. I use Jbugs for most of my VW stuff.
Craig.


Kerry
Posts: 1447
Joined: Mon Jan 07, 2019 2:42 pm
First Name: Frank
Last Name: van Ekeren
* REQUIRED* Type and Year of Model Ts owned: 1916 touring, 1916 pick-up, 1924 coupe, 1926 touring, 1927 touring
Location: Rosedale Vic Australia

Re: 12 volt ignition with 6 volt system

Post by Kerry » Wed Nov 10, 2021 11:39 pm

One way is to use a bendix spring at the starter + cable as a resistor.

User avatar

TRDxB2
Posts: 6262
Joined: Tue Jan 08, 2019 4:56 pm
First Name: Frank
Last Name: Brandi
* REQUIRED* Type and Year of Model Ts owned: Speedsters (1919 w 1926 upgrades), 1926 (Ricardo Head)
Location: Moline IL
Board Member Since: 2018

Re: 12 volt ignition with 6 volt system

Post by TRDxB2 » Thu Nov 11, 2021 1:30 am

The distributor body may be able to work on 6 or 12 volt. Its the coil that is matched to the car voltage (battery). So all you may need to do is use a 6 volt coil. What model distributor and does it have points? If it has an electronic ignition module setup then it is voltage dependent for sure. Also is the coil a 12 volt - check the model # and does it require a ballast resistor? Hard to give a definitive answer without knowing what you have - generator or alternator etc
--
--
Here is an example - so what do you have?
Attachments
front plate.png
The past is a great place and I don't want to erase it or to regret it, but I don't want to be its prisoner either.
Mick Jagger


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: 12 volt ignition with 6 volt system

Post by TXGOAT2 » Thu Nov 11, 2021 9:48 am

I think the Petronix replaces points and condenser. A set of stock points might still fit and would need to be installed with a 6 volt coil and condenser for a 6 volt VW application. VW used 6 volts into the 1960s, I believe. I do not know if they were positive or negative ground. It does matter. If the VW is not negative ground, a GM 6 volt coil and condenser should work fine with VW points. It's important to determine whether an ignition resistor was used with any particular parts used, and if so, it must be included and hooked up correctly. A system with a mis-matched coil and condenser will eat points, and a system with incorrect polarity willl have weak ignition performance. A system that requires a resistor will eat points if it lacks the resistor.


Original Smith
Posts: 3699
Joined: Tue Jan 08, 2019 10:43 am
First Name: Larry
Last Name: Smith
* REQUIRED* Type and Year of Model Ts owned: 13 Touring, 13 Roadster, 17 Coupelet, 25 Roadster P/U
Location: Lomita, California
MTFCA Life Member: YES

Re: 12 volt ignition with 6 volt system

Post by Original Smith » Thu Nov 11, 2021 10:45 am

You don't need any of that. Be sure to have a good starter and generator, and new wiring everywhere and 4 good coils, and don't forget, a good starter switch too. A good 6 volt system will spin your engine over as good as any 12 volt system.


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: 12 volt ignition with 6 volt system

Post by TXGOAT2 » Thu Nov 11, 2021 10:57 am

Agreed, but he already has the hybrid system in place.

User avatar

TRDxB2
Posts: 6262
Joined: Tue Jan 08, 2019 4:56 pm
First Name: Frank
Last Name: Brandi
* REQUIRED* Type and Year of Model Ts owned: Speedsters (1919 w 1926 upgrades), 1926 (Ricardo Head)
Location: Moline IL
Board Member Since: 2018

Re: 12 volt ignition with 6 volt system

Post by TRDxB2 » Thu Nov 11, 2021 11:05 am

Pertronics make all kinds of distributors so you can't assume that its a VW/Bosch or a Delco clip on or whatever. Need to know a model number, picture will help as well.
While we all agree that you don't need 12 volts, we also don't know why he says its 12 volts or has it.
"My 26 project came with a 12 volt pertronix in the distributor but I would love to run the rest of the car on 6 volt to protect the starter. Is this even remotely possible?" note the first words "My 26 project came with" doesn't say what else it came with.
Last edited by TRDxB2 on Thu Nov 11, 2021 11:23 am, edited 1 time in total.
The past is a great place and I don't want to erase it or to regret it, but I don't want to be its prisoner either.
Mick Jagger


Norman Kling
Posts: 4634
Joined: Tue Jan 08, 2019 1:39 pm
First Name: Norman
Last Name: Kling
Location: Alpine California

Re: 12 volt ignition with 6 volt system

Post by Norman Kling » Thu Nov 11, 2021 11:09 am

The starter spring will not really help with the problem. The problem is when the starter bendix first hits the flywheel which will be very hard with 12 volts. The spring in series will only help under load after the damage has been done. However, there are starters available which are wound for 12 volts.
Best thing I can think of would be to get a distributor which works on 6 volts and use a 6 volt battery, or fix your magneto and use coils.
Norm


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: 12 volt ignition with 6 volt system

Post by TXGOAT2 » Thu Nov 11, 2021 11:10 am

12 voilt ignition implies a 12 volt generator or alternator and battery, and might indicate an already abused 6 volt starter.


Topic author
kansasplowboy
Posts: 8
Joined: Sun Dec 01, 2019 4:00 pm
First Name: Randy
Last Name: Braddock
* REQUIRED* Type and Year of Model Ts owned: 26 RPU
Location: SW Kansas

Re: 12 volt ignition with 6 volt system

Post by kansasplowboy » Thu Nov 11, 2021 10:30 pm

Thanks for all the input guys. I have the Texas T conversion with a 12 volt pertronix electronic in it. It is a Bosch 009, so I think I will just buy the 6 volt version of the pertronix, a 6 volt coil, and call it good. I don’t have a generator yet, but that is what I’m going to run. I tried pulling my gen apart to rebuild it but for the life of me cannot get the pin to budge that holds the gear on. I’ve tried to drive it out from both directions thinking it might be a tapered pin but no luck. It looks and feels like it might have spent the last 30 years in the bottom of a swamp, the only usable parts might be the case and gear. I would like to just buy or trade for a rebuilt one.

Post Reply Previous topicNext topic