56 Cub 8V conversion?

I restored a 1956 Farmall Cub and have had nothing but trouble trying to get it to start and charge. Just ordered the 2nd Generator and have bought 3 regulators. I was told I could improve by going to an 8Volt battery which I just bought. There is a warning with it that says the VR has to be set to 9.2 V and if the vehicle has old style cut-out I should change to a 12V adjustable VR. Anyone using 8V battery? If so does it require these changes.

8 volt batteries are trouble fro the get go. 2 reason is you can not buy a charger to charge them up and #2 they are at best a band aid fix for other problems. Switch to 12 volts or fix the 6 volt problems. Yes you can have a V.R. adjusted to charge an 8 volt battery but you still have no way to charge it up if it where to go down. A 12 volt charger puts out to much and a 6 volt not enough so your still screwed

It doesn't matter what voltage your battery is,the system that charges it must produce more than the battery voltage..on 12v auto and truck most alternators put out 13.4 to 14,4v in order to charge 12v,put a tester on the posts of your car or truck battery with engine running and you will see the output vs when the engine is shut off,then you get pure 12v.An 8v battery would likely need 9.4v to charge it.
The auto shop I worked in checked alternator output first off when anyone came in with a "battery" problem,most of the time it was alternator failure and not battery.

A cub sure doesn't need anything more than 6 volts. What kind of problems are you having?

YES its "best" if you make those changes !!!

Ive used 8 volt batteries before but never was a huge fan of that oddball system preferring to either fix the 6 volt system or upgrade to the full more standard 12 volt instead. However YES they obviously make the starter spin faster well duhhhhhhhh. When there were "real" mom n pop genny repair shops they could tweak up a 6 volt VR for use in charging an 8 volt battery and yes 9 to 10 volts would be more in order for charging voltages. If you happen to have a three brush adjustable genny that also can be adjusted up if its NOT that way already.

The genny produces more if its spun faster and/or more current is pumped through its field windings which is what the VR regulates. A 6 volt genny even with a tuned up VR isnt gonna set the world on fire as far as super high charge rates are concerned, but again YES it can be made to work.

If you have a Low/High charge control light switch system (they were used with cutout relays as the charge control method), the low charge resistor value could be changed a bit.

Instead of buying an 8 volt battery and perhaps tweaking up a VR, if you instead convert to the full standard 12 I think you will be happier in the long run OOPS I SAW YOU ALREADY BOUGHT IT

Best wishes, got any real genny shops around?? If so Id let them make the VR adjustments

John T

The 6 Volts isn't your problem. The generator and regulator are your problems.

On 8 Volts, you still have to deal with the generator and regulator.

Take the 8 Volt battery back where you got it.

A "restored" Cub should have new battery cables and a rebuilt starter. Sounds like you didn't do that. New cables aren't too expensive, even 2ga Walmart specials are plenty. Get the commutator turned on the starter and new brushes installed. It'll work like new and practically flip the tractor over when you pull the rod.

Once the Cub starts good, you can almost live with the not charging thing by putting the battery on a charger/maintainer after every run.

thanks guys I guess I'll go back to 6v and sort out charging problem

That's what I would do. Fix it. I got 2 new battery chargers this year. A samll one that charges both 12 and 6 volt, with a maintainer setting and a larger rol away one with 200 amp boost that only charges 12 volt batts.

Thake the VR and genny into an auto electric shop and have em checked out and repaired as needed, starter too. Make sure the battery cables are good and that the genny and starter mountings can provide a good connection for ground.

Rick

Are you sure the starter is good?

Ask him not me

8 volt batteries and a tweaked voltage regulator was often used on IHC Ms in Minnesota, Dakotas in winters- and JDs As, 60,70s got same treatment. As for chargeing 8V battery? a 12 volt trickle charger or 4/6 amp 12 volt motorcycle/utility battery charger works good for the 8 volt golf cart batteries and utilities some times used in emergencies for winter use on a couple IHCs that had the snowshovel duty in northern Iowa and on some early VW bus enigines, pre-1966 Beetles. A couple 8 volt batteries are same size as the 6 volt batteries so fit in trays, lights will work with minimal burnout usually. The 8v quick swap works in emergency and a little general usage, covers the dirty cable ends problems awhile. As others noted- it is NOT the professionally preferred method, but it does work for many light users.