Slow starter

[Cool Hand Lurker]

About two years ago my 1930 Model A Tudor in fine shape with new inserted motor running nice went on the market for $12,500 and had over 2,000 inquiries but only one looker. Heavy on "LOOKER"... I took it off the market, lost interest, ignored it for a few months and then went to start it and the starter had little power. Pulled the starter, checked it out OK, new bushings & brushes, cleaned up the bendix, worked on the bench but it ran slow in the car. Pulled it and took it to somebody who "knew all about starters" plus a real shop who also checked it out OK. Reinstalled it, checked for a good ground, ran jumpers from a good battery, still too slow. Quit working on it for another year.
Got around to it again a couple months ago when son came back to town. Son said put in another NEW 6-VOLT BATTERY, no jumpers.

STARTED FINE RUNS FINE !!!!!

There was never a problem with the starter.

DUHHHH............... AAAAAAAARRGGHHHH

[Marshall V. Daut]

Yeah, but it didn't do the starter or you any harm to go through it and make sure it was up to snuff. Maybe a frustrating hassle for you, but at least you can cross a weak starter off the list when future problems like this creep up. Oftentimes it is the simplest thing that causes such problems, meaning a new battery solved the slow starter problem. The way batteries are made today, getting two good years out of them is a miracle. And it doesn't seem to matter whether you spend a lot or a little, they still go bad by the third year, if even that long. I have paid close to $200 for a six-volt high visibility name brand battery that didn't last any longer than a $50 no-name battery purchased at a local tractor supply house. What does THAT tell us about getting what you pay for in life anymore??? I think that tried-and-true homily needs to go by the wayside from now on.
Marshall

[Terry, NJ]

Here's my solution! When you check the ground path, you'll note that it runs through some the original frame rivets and that could be problematical. The thing to do is to use a brass5/16 or 3/8 bolt through top of the chassis flange. Attach the ground cable from the battery on the top of the flange and run the new cable from the underside of the brass bolt over to the bottom bolt of the starter. The reason it ran so good for you on the bench is that the current didn't have all that rust to make it through.
I had been hearing about Auxillary Ground cables for years so I decided try one out. I attached a 12V (yes! a 12V cable) as described above. I couldn't believe the difference in the speed of the starter. Night and Day! Coincidentally, this also means that batteries will charge faster, the charge will give more spins at higher RPM, and will last longer. The draw down is not as severe.
Terry

[nkaminar]

It is really simple to just measure the voltage at the starter when cranking the motor. Half the rated voltage of the battery and either the battery is bad or there is electrical resistance somewhere in the path of the electrons. If the voltage is near the battery's rated voltage then the starter has a problem or the switch is bad. Measure the voltage at a one of the bolts on the starter and the battery cable that connects to the switch. You can buy alligator clips that connect to the voltmeter leads or make some up from scratch.

[Cool Hand Lurker]

I think a combination of things was the problem. Old battery that would not hold a charge. Jumper cables for 12Volt were used but they are thinner and won't carry the amps required for 6Volt. They did get hot. Ground was definitely poor. But a new 6Volt battery in stock location meant shorter thicker 6Volt cables with cleaner ground and power connections that gave full energy and made that critter pop!


Thanks for all the comments!

[700rpm]

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Two years from a battery!! I feel lucky if I still have a warranty at 13 months.

[nkaminar]

As I write this my Model A is hooked to a battery maintainer. I have not driven the car in a while for various reasons. A battery maintainer will save your battery. Get one that is designed to desulfate the battery. This type of battery maintainer sends high frequency pulses that convert the crystalline form of lead sulfate back to the amorphous state so that it can be used by the battery. A battery that sits for a while will self discharge and a partially discharged battery will form the lead sulfate crystals. The lead sulfate crystals degrade the battery.

Batteries can be killed in a number of ways. Leaving them partially or fully discharged is one way. Over charging is another. Letting them go dry is another.

[Bob Bidonde]

The inevitable is a change to a 12V electrical system with an alternator. I think that the manufacture of 6V batteries is going into history. Also in my opinion, every Model "A" should have an auxiliary ground cable.
For the record, having run 12V in both my Model A's for many many years & miles, the stock starter motors work extraordinarily well, and I see no ill effects to the flywheel ring gears. However, the stock Bendix Starter Drive is junk, so I converted both starters to modern starter drives that are made in the USA.

[Rob Doe]

I'll add that the Les Andrews blue book "Trouble Shooting and Diagnosis" has excellent descriptions of how to easily voltage test the Model A Starting System and all the other systems too. The diagnosis procedures described will help the novice perform the steps in the proper sequence as a skilled mechanic would do.

The overall health, state of charge, of your battery would have been your very first step in resolving the dragging starter issue. I'm new to the Model A also. When I can't sleep at night. I pull out this manual and review its contents. Over and over and over! (I don't sleep well. LOL)

Hope this helps someone.

[Bob Bidonde]

According to Dyke's Encyclopedia, the starter motor draws 175 Amps at 6V while cranking the engine with a (+) ground. The starter motor produces 3 lbs-ft of torque at 1500 RPM.

Running free, the starter motor draws 50Amps at 4000 RPM

A high compression cylinder head will increase the load on the started, so it draws more current from the battery. A modern battery should have about 500 Cold Cranking Amps capacity at 6V.

[Fullraceflathead]

£3 of torque seems like a misprint did you mean 30lbs of torque?

[Bob Bidonde]

I added some slides to Post #10 that explains the starting gear ratios. The gear ratio of the starter to ring gear is 115/11 or 10.5:1. In this case, 3 lbs-ft of torque is multiplied to 31.5 lbs-ft. Running a 12V battery should double the torque.

[Synchro909]

Originally Posted by Fullraceflathead

£3 of torque seems like a misprint did you mean 30lbs of torque?

In the imperial system, torque is measured in ftlb. That is, multiply the length of the lever by the force applied to it. Which is greater, 1 lb of force applied on a lever 30 ft long or 15lb on a lever of 2 ft?
They are the same.

[Synchro909]

Originally Posted by Bob Bidonde

The inevitable is a change to a 12V electrical system with an alternator. I think that the manufacture of 6V batteries is going into history. Also in my opinion, every Model "A" should have an auxiliary ground cable.
For the record, having run 12V in both my Model A's for many many years & miles, the stock starter motors work extraordinarily well, and I see no ill effects to the flywheel ring gears. However, the stock Bendix Starter Drive is junk, so I converted both starters to modern starter drives that are made in the USA.

Bob, I whole heartedly disagree with that. I have seen too many of the modern style Bendixes thrown as far as the owner can throw them. I have done the same. Far and away, I prefer an original style Bendix on a starter converted to 12 volts.
I have also seen too many unmodified starters with bent shafts, even the 5/8" shafts bent like bananas by running them on 12v without modifying them.
BTW, Henry found that the 1/2" shafts were not up to the job so he changed to 5/8". That strengthened the shaft by a little over 50%. Putting 12 volts through an unmodified starter theoretically increases the power it generates by 400% - way more than it is reasonable to expect the starter to withstand for long.

[eagle]

If you buy a farm rated battery and you treat it well, it should last for at least 8 years. Treating it properly: 1. keep it charged while sitting. This may be accomplished with a battery maintainer or by periodic toppoff with a 2A trickle charger. 2. Make sure you are not overcharging with the generator. I use a voltage regulator on my generator, works perfect. 3. Make sure you have clean electrical connections and heavy enough cables, Also a good idea to run a ground strap from ground on battery to the engine block. If you have to replace your battery more often, you've got a problem somewhere in those three things. Yes, you may have gotten a bad battery, but not likely more than one.