The Stovebolt Site Forums The Shop Area The Electrical Bay Not Enough Oomph to Start

1949 model 3200 panel truck fully restored including electrical. I charge the battery for 5 days and there is not enough oomph at times to roll the engine fast enough to start well. I'm considering installing a second battery, but my question is do I put them in series or parallel to get more starting power out of them? If parallel then where can I get 6 volt wires with two battery hook ups? Does anyone have any other suggestions, and yes the engine, starter wiring, battery cables were either rebuilt or replaced new. Thanks


Dave

Hy Panelit, did you use battery cables for six volts, or twelve volt cables off the shelf at the f.l.a.p.s.? Six volt cables are twice the size (diameter) of twelve volt cables. You could try doubling up on the cables.

A properly set up and wired 6 volt system with a good battery should not need a second battery. You've either got cables that are too small, dirty connections, or a battery that does not have enough reserve capacity. Start out by finding someone who can test the battery properly to be sure you're not dealing with one that just can't produce. Even "new" batteries and/or parts can be defective.
Jerry

As mentioned, "complete restoration", which included "new 6 volt cables", connections were "cleaned twice" to make sure they were good. Starter is good, but perhaps your right Jerry, maby the battery just isn't charging well. But if I had two batteries would they go is series or parallel, and could I hook up a 12 volt radio to the two batteries and get 12 VDC? Thanks for the help.


Dave

Connecting the batteries in parallel would allow twice as much current to go to the starter without having to modify the charging system, etc. If you connect in series, you might as well do the whole 12 volt conversion routine, because it won't be possible to put 12 volts to only the starter - - - -the whole system will get it, and things will smoke instantly. Get the battery tested by a pro who knows what he's doing! The procedure involves a full charge, and a heavy current load of 1/2 the cold cranking amp rating for 15 seconds. There's at least a strong possibility the battery is the one and only problem.
Jerry

Just the facts ma'am.

Uhhh what about the battery ratings? I think they would matter somewhat.

Dan Bentler

i'd get the battery load tested. my money is on a weak battery. when charging a 6 volt battery use a trickle charger the big ones tend to fry the cells.

The testing standard for an automotive cranking battery is a load of 1/2 the cold cranking amp rating for 15 seconds, and a voltage reading taken while the load is still on. 6 volt batteries should be able to maintain a minimum of 4.5 volts, and a 12 volt needs to maintain at least 9.6 volts. Deep cycle batteries like those used in forklifts, power wheelchairs, or for trolling motors won't be able to deliver that much surge current, but they can be safely discharged down to 75% of their capacity. Starting batteries don't work well if they're discharged more than 25% routinely.
Jerry

Make sure your grounds for the battery and engine are clean

Dave if you just rebuilt the engine as you stated in the initial posting, them it may
just be that the engine is still tight enough to hold it back. As Jerry eluded to, a
properly maintained 6v system is perfectly adequate to start that engine.

Originally these engines were run up and tested in engine cells at the factory for a
few minutes while they adjusted the valves and inspected them for any odd noises.
So they had just enough run time on them that the rings broke the tops on the
honing cross hatch. The drag on 18 tight new rings in a freshly honed cylinder can offer quite
a bit of resistance. Also make sure your timing is set correctly on the ball and not advanced.

I'd bet after you run the engine for 15-30 minutes that it would turn over a whole lot easier.
Denny Graham
Sandwich, IL

Silly question proably, did you check the water level in battery after charging for 5 days. charging cycle will evaporate water over time. battery won't hold a charge properly if waterlevel to low.

Haven't heard from Dave for a while, wondering if he found is problem and will share it with us.

Denny Graham
Sandwich, IL

No, I have not found the problem yet, but I am going to purchase a new 6 volt battery. The ground connections are good, tight, and clean, but I read somewhere on Stovebolt about adding an extra ground strap and additional ground connections at other locations in the truck, I think it was posted by Jerry. If that could be explained and some specific details provided as to where they should be provide I would appreciate it. Thanks.

God bless,

Dave

If you can turn the engine over by hand with the fan, then the starter should do the job. If you can't then the starter may be over taxed. To help start it the first time, I power the coil separately with a battery charger. That way you get the full spark while the starter is drawing power and dragging down the system voltage.

Just installed and got my freshly rebuilt engine running last week. Bored, new alum pistons, crank ground .010 under, insert rod mods. When I had it on the engine stand buttoning everything up she was tight but not to tight. I’m sold on the stock 6v system and don’t think they need anything more than what they came with. Before lighting the fire I had run up the oil pump to get oil to the crank and rockers. For the first start I cranked her over three or for times for 15 or 20 seconds at a crack with the ignition off to get fuel thru the system. When I switched her on I touched the starter and she popped of first turn over. Since then I've driven it out on the road keeping the R’s up to make sure I’ve got plenty of oil up on the cylinder walls and varying the engine speed with hard acceleration to keep the pressures high in the cylinders and force the rings out against the walls. I gave her plenty of breaks to just let her breath and was down the walls. Put over a hundred miles on the new engine and started it a couple dozen times and it’s the same routine, touch the starter and first turn over it lights.
Brand new engine--6v Farm & Fleet 640cca three year old battery--no problem!

Denny Graham
Sandwich, IL

The original ground setup was a short braided bare cable from the battery (-)post to the body or frame, I don't remember which, and another braided ground strap from the engine to the frame. That setup adds two extra connections to the circuit which can develop corrosion or looseness. I prefer to use a long, heavy ground cable from the battery to the engine block or one of the starter attaching bolts, so the starter current has the shortest, most direct path back to the battery. Smaller ground straps can be used to connect the body and/or the frame to the engine for grounding headlights, tail lights, accessories, etc. The starter and the ignition system need to have the very best, lowest resistance ground connections possible. A #1 or #0 battery cable long enough to reach from the starter housing to the battery negative post is the best way to accomplish this result.
Jerry