6 volt vs. 12 volt

[81deeds]

Would really like to talk to you in person...im new to this era but fabricator mechanic my whole life...i want to to make mine reliable also...curious on all connections...
Derek
Foster r.i.
401-749-7491

[donQ]

Your concern appears to be cranking the engine fast enough to start it. If you're not planning to run it much at night, the 6 volt system will be fine. If you've cleaned out the sludge from the oil pan, you can run a good quality 20-50 multi vis oil that will help with cold starts. The suggestion made by others to install a redundant ground ( 19 inch between rear bolt for E-brake handle to frame cross member where Battery ground is) will help a lot.
donQ

[Tom Wesenberg]

6 volts is 100% reliable and cranks the engine plenty fast to start. Hand cranking is much slower, but it also fires the engine right off.

[Purdy Swoft]

Hand cranking doesn't require draw from the starter, Thats why the engine will start with the hand crank when the battery is too weak to power the starter and the points at the same time. I gave our roadster all of the advantages for easy starts. I use 12 volts , 20W50 motor oil, an extra ground cable and a performance 3.0 OHM coil. When the original generator is used, none of this stuff shows and is really a big advantage.

My girls aren't mechanics and I want to be sure that they can crank our model A's even if i'm not around. I can usually make just about anything crank and start but I really don't mind the quick starts and other advantages that 12 volts gives and neither does the model A .

[Bob S]

Just out of curiosity, I tried starting my '29 A a couple of weeks ago when it was a few degrees below zero F. It cranked a bit slower than usual, but started right up. Stalled when I let off the clutch in neutral (trans lube was probably like taffy), but started right up again.
Two year old battery that hadn't been used or on a charger for well over a month.
10w40 oil.
Big battery cables and good clean connections.

Bob

[aojo]

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purdy, you are on the money!

[Tom Wesenberg]

"The car starts quicker on 12V putting less strain on the starter motor."

12 volts is actually much harder on the starter and drive. A well tuned Model A will start within a few compression strokes, so the starter should only be in use for a few seconds anyway. My GPS works fine on 6 volts as do my friend's cell phones.

[Marshall57]

Originally Posted by Purdy Swoft

If lots of accessories and the very best brightest headlights are used, You will need to use an alternator. Being as I've got A Brattons catalog handy I will give recommendations and part numbers. I recommend the 12 volt 60 amp alternator that will support 60 watt halogen bulbs at idle. Page 65 part number 14960 price $185.00 .This is a one wire hook up alternator that operates on negative ground and will power all accessories. I recommend the Quartz halogen kit that is complete with reflectors and everything that you will need. This kit uses 60/55 watt bulbs that are focused and are just as bright as modern cars. Page 79 part number 17850 price $97.00. I use a 3.0 OHM coil that is internally resisted. The original style wiring harness works great. When converting to negative ground, the wires need to be switched at the ammeter and at the coil. The rest is just common sense stuff. Connect the 12 volt battery negative ground Replace all other bulbs with 12 volt, I use 10 candle power tail lamp bulbs but more powerful halogen bulbs are available in most model A parts catalogs. The 6 volt horn will need a resistor. I have used the original starter on twelve volt on many applications for 50 years with no problems. Some prefer to spend the money to have the starter converted with different field coils. The 12 volt field coils are an expensive mod that usually requires an electric shop to perform. It slows the starter and is a waste of money in my opinion. If the flywheel ring gear and starter drive is in good condition, the unmodified starter works good for me on 12 volt.

This is just the ticket I was looking for, thank you and if there are any other ideas as to which parts anyone else is having good luck with please chime in..
Is there a distributor issue when converting to 12 volt? I am running a completely stock 6 volt system at present.

My plan is to up date the ole girl and run her from Nevada to Washington to the Nationals in June, so here in the frozen west I am gathering parts and ideas.

Thanks again to the ford barn bunch for all the great information.

[Purdy Swoft]

The original distributor and points work great on 12 volts. I use the A&L short proof condenser that is sold by Brattons, Snyders and most other good model A vendors. I use and recommend the Pertronix epoxy filled flamethrower coil. The 3.0 ohm version coil works on 12 volt without the use of a ballast resister and gives electronic type performance. The modern barrel style starter drive is a good option. The original starter drive is famous for dropping bolts in to the flywheel housing ,no matter what volt system is used. I recommend the modern front bearing and sleeve on the water pump in any case. The use of an alternator puts more strain on the front water pump bearing and the modern bearing and sleeve is more durable in any case.