6 volt starter turn over slow or fast?

[Sactownog]

I have my starter being rebuilt by Richer Auto & Truck Electric in Oceanside, ca. I am excited to get my starter and generator back because when I got the car the starter looked to be original and never updated or replaced. the Generator had been rebuilt at one point after seeing it cracked open, some of the wires were new some were old. 

 

I have never heard the car turn over with a like new 6V starter, so my question is, will the starter turn over the way it did before which was slow and sluggish with the lazy "row --- row ----- rowwww---------vroom" 

 

or will it start like a new style starter "row- row - vroom? "

 

 

[Wheelmang]

I cannot speak to the vroom part after a couple of row row but rebuilding mine did not speed up the cranking speed.

[trimacar]

On the six volt, use large battery cables (not the skinny 12 volt cables), and personally I run a separate ground directly from the battery to one of the starter bolts.  Makes a HUGE difference, rather than the ground trying to find it's way through corroded frame joints and such.  Even if you say "oh, my frame's restored", you didn't take the riveted joints apart and clean 90 years of corrosion from between them.  Good luck!

[Silverdome]

X2 on the heavy cables. On my '48 Plymouth I used double 0 on battery negative to solenoid and solenoid to starter then I used single 0 from battery positive to ground.

[Reg Evans]

What Trimacar and Silverdome said !

[Sactownog]

OK, So the starter will not crank any quicker or faster than it did before, I have had new cables made, not sure what size they are, but I will check. 

 

I am curious where I would hook a negative battery cable to the starter. maybe where the bolts connect to the bell housing? 

 

I also have been told that I should add a ground wire from the engine to the frame. 

[Guest]

The starter should turn over as fast as any 12 volt starter of the fifties and sixties.  The reason to run a ground from the engine to the frame  if you have run the ground from the battery to the engine is so you lights will have a good ground.

My Pontiac came from the factory with a ground running from the frame around a front motor mount to the engine.  Everything worked really well until the eighties when the starter seemed sluggish.  I had the starter rebuilt (it needed an armature) for the first time at about 350,000 miles, grounded the battery to the starter mounting bolt and it spun just like it had done in the fifties.

[keiser31]

I agree with Tinindian. When I crank the '31 DB coupe, it cranks fast and strong as long as the connections and ground are good. Yours should, too.

Edited July 9, 2018 by keiser31 (see edit history)

[trimacar]

This seems to be a sticking point for a lot of people not as familiar with how electrical current works, no offense meant, just a fact.

 

So, they go to the store and say "I need two battery cables" and end up with 12 volt rated cables (about the diameter of your little finger).  What they need are 2/0, or double ought, cables, at a MINIMUM for 6 volts, to get the amps to the starter motor.  2/0 wire is about the diameter of your thumb.  All this is assuming you have more or less normal hands and you weren't the body double for Andre the Giant.

 

You can never go wrong going with bigger wire, but you can make your starting life miserable by going with smaller wire.  The ones who don't know hear that starter going UR..URRR...UR...URRR ever so slowly, then spend a bunch of time and money going to 12 volts on the car because it's "better".  It's not.  6 volt cars started fine when new, they can start fine again.  How many cars do you think a dealer would sell if that's what the buyer heard on a new car?

 

Good luck!

 

 

[Bloo]

Engines ran slower back then. They had much slower redlines, much slower idle speed, and a camshaft tuned to those lower speeds. As such, the necessary cranking speed was lower, a LOT lower. It hadn't been that many years since we were cranking them by hand.

 

It really boils down to the design of the starter motor, and the gear ratio from the drive pinion to the crank. The engineer could have picked anything. What he picked varies by make and model.

 

It might very be well be normal for it to crank slow. It should start right up. The real test is can it crank for a little while. If you are getting three chugs or something, and thats it, and you have to wonder whether it is going to start or not before you run out of battery, then something is wrong. The starter should not sound labored, just slower than something modern. It should be able to crank for a little while without slowing down much if any.

 

If it is pulling way down to a stop when every cylinder comes past, the system voltage is probably getting pulled down to nothing, and that will cause hard starting because the ignition just doesn't have enough voltage to work. A stalled electric motor draws an unbelievable amount of current.

 

Like Tinindian, my Pontiac (1936) cranks crazy fast for an old car. I don't think that is typical or normal for the era. Slow but steady for most cars. I have a good battery and big reproduction cables (RI Wire). I think they are 0 gauge, but might be 00.

 

There are much cheaper sources for big cables than RI wire if you don't need them absolutely authentic. A parts house for tractors will have 6 volt stuff right on the shelf. Straps were often used for the "ground" or chassis side (be it positive or negative) and they work fine. Don't neglect the "third cable" (or strap) from the engine/trans to the frame.

 

Next time you see a Model A Ford, listen to it crank.....

 

RUUrrrrrrrrrRUUrrrrrrrrrrRUUrrrrrrrrrRUUrrrrrrrrrrrRUUrrrrrrrrrRUUrrrrrrrrrrrRUUrrrrrrrrrRUUrrrrrrrrrrr

 

 

[Matt Harwood]

Pre-war Packard 356s crank agonizingly slowly. Every 1941 Cadillac I've had cranked so slowly you'd think it would never fire and just about the time you're about to give up, it fires. Speed isn't necessarily the point. You want it to have enough velocity to pull some fuel and air into one of the cylinders--enough to fire when the plug's turn comes. As long as it turns consistently and doesn't bog down, as others have said, it is probably working properly. My three six-volt cars have markedly different cranking speeds but they all fire reliably. I upgraded the cables and grounds on the '35 Lincoln, as well as using two Optimas, and that sucker cranks over even when it doesn't want to. It just doesn't have a choice anymore; it WILL start. It doesn't crank any faster, but nothing slows it down, either. Not heat, not compression, not cold, nothing.

 

 

[Alan Cutler]

I used the leads from my MIG welder, built them myself, bought the ends and soldered it with my torch, don't really know the gage, but its thicker than my thumb....and I am told I have sausages for fingers....?

[Bloo]

I have also used welding cable. I had some custom cables made in 00 welding cable for a 12v Cadillac (high compression 472) that didn't like to crank. I was cautioned that it was not as oil resistant as real battery cable. Not a problem on that car. 00 welding cable is MUCH more flexible and easy to work with than 00 battery cable. It really cranked good with those. What a difference!

 

 

 

[Alan Cutler]

The flexibility and gauge are huge advantages....The guy that taught me everything I know about cars, Ed Parrish, showed me that trick, when we were trying to jump start cars on the side of the road....he always said the last thing you need when on the side of the road was bad tools....so we always made our own jumper cables, to the length we wanted....I just took that same idea and made the leads for my car at the time.

[Matt Harwood]

The generator/alternator rebuild shop up the street from my place makes me these awesome cables:

 

 

 

Those four cables in 1/0 size with ends were about $45. Very flexible and easy to work with. If you need cables I can put you in touch with them and I'm sure they'd make you some and ship them to you. They know old cars very well and do all my starter/generator work. Right now they've got a starter/generator from a 1916 Cadillac on the workbench--very cool!

[Silverdome]

19 hours ago, Sactownog said:

OK, So the starter will not crank any quicker or faster than it did before, I have had new cables made, not sure what size they are, but I will check. 

 

I am curious where I would hook a negative battery cable to the starter. maybe where the bolts connect to the bell housing? 

 

I also have been told that I should add a ground wire from the engine to the frame. 

 

Has your car been changed to a negative ground?

If not then the negative cable going to the starter would go on the threaded post.

[Spinneyhill]

22 hours ago, Sactownog said:

I am curious where I would hook a negative battery cable to the starter. maybe where the bolts connect to the bell housing? 

 

As @Silverdome says, put the earth = ground onto the starter solenoid post. Mine has a wing nut; the cable goes on when I go out and comes off when the car is in the garage. My car (1930 Dodge ? has a wee wire holder loop attached to the top of the rear engine mount =cross member for the cable; it looks original so I am guessing that is the original place for the earth wire. Yes it cranks slowly, but strongly and always starts when fuel reaches the carb.

[trimacar]

19 hours ago, Bloo said:

It might very be well be normal for it to crank slow.

 

I just have a hard time with that statement, although one could never prove it one way or the other how they cranked when new.  When all connections and components were new and shiny and frames had no corrosion so electrical path was clear, I think that new cars of the 20's and 30's cranked just fine with the starter.....

 

I can tell you that my 1927 Dodge cabriolet does not crank slow, it's 6 volts, with a ground run directly to starter, and it will turn over fast enough to fill an EMPTY vacuum tank just from cranking........in very short fashion....

[Sactownog]

3 hours ago, Silverdome said:

 

Has your car been changed to a negative ground?

If not then the negative cable going to the starter would go on the threaded post.

I have not changed to negative ground. it is still a positive ground system. 

now that I read all of the comments, I will add some grounds. my positive (negative or black wire) will go to Starter bolt on top where peddle engages starter, my negative goes to the top of the transmission behind shiffter. 

 

the other negative I will run from where the Starter bolts to the Bell housing to the frame somewhere. 

 

should I run another ground somewhere else?  

[maok]

The turning speed is based on the Voltage the starter motor is feed, hence the reason why a 12 volt battery will turn over a starter faster than a 6 volt battery. Note, the battery needs to be able to supply enough amps (ie CCA of the battery) to handle the resistance of the of  the engine. If your car does take time to fire, thicker cables are important, especially for a 6 volts system.

[Bloo]

1 hour ago, trimacar said:

 

I just have a hard time with that statement, although one could never prove it one way or the other how they cranked when new.  When all connections and components were new and shiny and frames had no corrosion so electrical path was clear, I think that new cars of the 20's and 30's cranked just fine with the starter.....

 

I can tell you that my 1927 Dodge cabriolet does not crank slow, it's 6 volts, with a ground run directly to starter, and it will turn over fast enough to fill an EMPTY vacuum tank just from cranking........in very short fashion....

 

I doubt we are really in disagreement here. I just happen to think many cars were designed to crank slower then, not crank too slow, or crank badly.

 

I do expect them to do what they did when new. I don't expect them to go CHEEeCHEEeCHEEeCHEEe like a modern vehicle that idles at 800rpm, revs easily to 6000rpm, and probably has a gear reduction starter. No way were the old ones designed too weak to do the job.

[trimacar]

1 hour ago, maok said:

The turning speed is based on the Voltage the starter motor is feed,

Not true at all.  Just because "12" is a larger number than "6" does not mean a starter will work better, c'mon people, get some education and learn how electricity works.  Amps are what matter, and having a full electrical circuit to the starter.

 

[trimacar]

Just now, Bloo said:

doubt we are really in disagreement here.

I somewhat agree that we don't disagree.  To your point, no, the earlier cars probably didn't spin like banshees when started.  However, I feel they spun much faster than most people think, as there's no logic put into an old car now original, semi-restored, or restored.  When new, all the metal touching metal was bright and shiny and conducted the charge very well.  Now, not so much.  Thus, one has to take into account the condition factor of grounding, and the nature of electricity.  It's just like an old man, a nice, clear path, no problem, but put some obstacles in the way and whoops, not so easy....

[maok]

12 minutes ago, trimacar said:

Not true at all.  Just because "12" is a larger number than "6" does not mean a starter will work better, c'mon people, get some education and learn how electricity works.  Amps are what matter, and having a full electrical circuit to the starter.

 

 

The below is from this site - https://electronics.stackexchange.com/questions/39387/how-are-current-and-voltage-related-to-torque-and-speed-of-a-brushless-motor

 

In any motor, the basic principle is very simple:

• rotational speed is proportional to voltage applied
• torque is proportional to current pulled

A 100 volt motor is a motor that can take a maximum of 100 volts, and a 50 volt motor a maximum of 50 volts. Since the 100 volt motor can take more volts, if all else is equal, it can give you a higher maximum speed.

But the difference in voltage does not affect the torque. To get more torque to go up a hill, you need to supply your motor with more current. A motor that can take more current (and a battery and motor controller that can supply more current) will give you more torque to help you up the hill.

[Bloo]

It will turn at it's designed speed on 6 volts. The crank will turn at a speed determined by the ratio of starter gear teeth to ring gear teeth. If you put 12 volts on a 6 volt starter, yes it will spin faster, and the engine will spin faster too. The starter will have to dissipate over twice the power as heat that it did on 6 volts. You will probably get away with it for a while, maybe not forever.  A 6 volt bulb burns really bright on 12v as well.....

 

The question that needs to be asked is "why is it so hard to start?"

 

The engineer didn't say "Oh, woe is me! There are only 6 volt batteries and this damn thing will never start!" He designed it to spin at whatever speed he thought it needed to start, plus some headroom. There were not a bunch of Hondas and gear reduction Chryslers for a frame of reference on what a starter should sound like. The frame of reference was a hand crank. Most cars through the mid 30s were designed to still start with one if necessary. The owner was probably just happy he wouldn't need to use one anymore

 

Remember Dodge Brothers (and probably others) had 12v in the 1920s and abandoned it.

Edited July 10, 2018 by Bloo (see edit history)

[trimacar]

35 minutes ago, maok said:

 

The below is from this site - https://electronics.stackexchange.com/questions/39387/how-are-current-and-voltage-related-to-torque-and-speed-of-a-brushless-motor

 

In any motor, the basic principle is very simple:

• rotational speed is proportional to voltage applied
• torque is proportional to current pulled

A 100 volt motor is a motor that can take a maximum of 100 volts, and a 50 volt motor a maximum of 50 volts. Since the 100 volt motor can take more volts, if all else is equal, it can give you a higher maximum speed.

But the difference in voltage does not affect the torque. To get more torque to go up a hill, you need to supply your motor with more current. A motor that can take more current (and a battery and motor controller that can supply more current) will give you more torque to help you up the hill.

 

I stand corrected.  I'm a mechanical engineer, so don't believe in electricity.  Let me amend my statements to say that 6 volts will turn over an engine very nicely, IF all components are correct, with plenty of torque.  I honestly didn't know...thanks

[Alan Cutler]

2 hours ago, Bloo said:

The starter will have to dissipate over twice the power as heat that it did on 6 volts. You will probably get away with it for a while, maybe not forever.  A 6 volt bulb burns really bright on 12v as well.....

 

The question that needs to be asked is "why is it so hard to start?"

 

2

 

So true, when I rebuild my 6v starter, I noticed the winding leads that are soldered to the armature, had melted....meaning they got hot at some point prior to my ownership...this can only happen by two reasons;

 

1) A direct short

2) A 12 volt generator/battery combination (I called a previous owner and he told me he used a 12v battery at one point, just to get it started a "couple" of times....)

[maok]

16 minutes ago, Surf City '38 said:

 

So true, when I rebuild my 6v starter, I noticed the winding leads that are soldered to the armature, had melted....meaning they got hot at some point prior to my ownership...this can only happen by two reasons;

 

1) A direct short

2) A 12 volt generator/battery combination (I called a previous owner and he told me he used a 12v battery at one point, just to get it started a "couple" of times....)

 

Its unlikely it was because a 12 volt battery was used a couple of times. I have been running my '28 Chrysler with a 12 volt battery for nearly  3 years (it was running with a 12 volt battery before I got it as well) and I start the engine more than most.

 

Its the current (amps) that produces the heat in combination with resistance and time, not the higher voltage. Remember, there is less amps going through your starter when powered by a 12 volt battery than a 6 volt battery.

 

The total 'power' (Power = Volts x AMPs ) used is approximately the same regardless if its powered by 6 volts or 12 volts.

[cahartley]

A BAD connection will cause the starter to heat as current flow through each winding has much longer duration than a starter which spins normally.

When I got the Confederate (in my avatar) the engine would barely turn over with a brand new battery.

I found a questionable connection in the hot cable terminal end which connects to the starter.

I removed it and verified it was a lousy connection.

I yanked out the cable from the terminal end, cleaned up things and soldered it.

Now the starter spins the engine as if there were no pistons in it.

Night and day!....... ?

[Bloo]

5 hours ago, maok said:

Remember, there is less amps going through your starter when powered by a 12 volt battery than a 6 volt battery.

 

The total 'power' (Power = Volts x AMPs ) used is approximately the same regardless if its powered by 6 volts or 12 volts.

 

Lets say you have a 6v starter with .05 ohms resistance (while turning).

 

6volts / .05ohm = 120 amps  (Ohms law)

 

120 amps x 6 volts = 720 watts

 

Now, connect 12 volts to that starter

 

12 volts / .05 ohm = 240 amps (Ohms law)

 

240 amps x 12 volts = 2880 watts

[robert b]

Yes Bloo you are correct ,2 x the voltage is 4 times the power and can it do a lot of damage to these starter motors , never a good thing to convert to 12 volt.My 6 volt systems after 40 years of service has never failed as long as the battery is charged of corse .

[Alan Cutler]

Three bright solder leads coming off the armature field leads...got hot and melted at one point.

[Silverdome]

18 hours ago, Sactownog said:

I have not changed to negative ground. it is still a positive ground system. 

now that I read all of the comments, I will add some grounds. my positive (negative or black wire) will go to Starter bolt on top where peddle engages starter, my negative goes to the top of the transmission behind shiffter. 

 

the other negative I will run from where the Starter bolts to the Bell housing to the frame somewhere. 

 

should I run another ground somewhere else?  

The threaded post on the starter is insulated from the starter case. The starter case is NOT insulated from the transmission, bell housing, engine, frame or body. So negative cable to the threaded post, positive cable to the starter case, transmission, bell housing, engine, frame or body.

 

If you touch your negative cable from your battery to any of these, the starter case, transmission, bell housing, engine, frame or body, you will get a spark or worse such as a burned wire if you are truly positive grounded.

[maok]

12 hours ago, Bloo said:

 

Lets say you have a 6v starter with .05 ohms resistance (while turning).

 

6volts / .05ohm = 120 amps  (Ohms law)

 

120 amps x 6 volts = 720 watts

 

Now, connect 12 volts to that starter

 

12 volts / .05 ohm = 240 amps (Ohms law)

 

240 amps x 12 volts = 2880 watts

 

And yet you need bigger cables with a 6 volt battery. How could this be Bloo?

 

Your use of Ohms laws is fine when the motor is not moving but when the motor moves it becomes a dynamic electrical circuit with back EMF affecting the circuit. So its complicated. Someone with a higher pay rate can explain it better than I can.

 

I used the power equation in my earlier post because its simple. The engine requires the same amount of power (actually its probably slightly more with the 12 volts because of the faster spin speed causing some more friction) to turn it over regardless of the battery voltage.

 

Regarding the heat generated, you have to take into account 'TIME', a starter motor only spins for a few seconds at the most, hence the reason why they don't have a cooling fan built-in, unlike an alternator/generators. With a reasonably tuned engine, starter motor does not get hot enough because it is only spinning for 2-3 seconds at a time. If you have a badly tuned engine then yes, heat will cause issues inside the starter motor, but this is regardless of the voltage, specially if the starter gets stuck in the flywheel gears.

[Bloo]

39 minutes ago, maok said:

 

And yet you need bigger cables with a 6 volt battery. How could this be Bloo?

 

You need the same amount of watts (power) to turn the engine over at a given speed. If you use a starter designed for 12 volts, you only need half the current, and therefore smaller wires.

 

 

 

Edited July 11, 2018 by Bloo (see edit history)

[maok]

An interesting experiment would be to place a DC clamp meter (on the amps setting) around the starter motor wire with 12 volts and 6 volts batteries.

[Sactownog]

OK, so let me ask you this, my Ground goes from the top of the battery to the top of the transmission where the sifter is located. There are bolts that hold on the sifter cover to the transmission. that is where my ground was and is currently screwed onto. 

 

I have been told this is where the Ground wire belongs on my car. 

 

I have also been told that it would be a good idea to run multiple grounds from the frame to the engine up front. 

 

PLEASE TELL ME, is the current ground enough, and should I run a ground from engine to frame up front?  

[keiser31]

16 minutes ago, Sactownog said:

OK, so let me ask you this, my Ground goes from the top of the battery to the top of the transmission where the sifter is located. There are bolts that hold on the sifter cover to the transmission. that is where my ground was and is currently screwed onto. 

 

I have been told this is where the Ground wire belongs on my car. 

 

I have also been told that it would be a good idea to run multiple grounds from the frame to the engine up front. 

 

PLEASE TELL ME, is the current ground enough, and should I run a ground from engine to frame up front?  

This is the way it is on my '31 and it works great....notice the ground on the transmission.

[maok]

37 minutes ago, keiser31 said:

This is the way it is on my '31 and it works great....notice the ground on the transmission.

 

Same as my '28.

 

But the Firestones on my '28 don't have enough grip to drive sideways on walls....?

[Bloo]

2 hours ago, Sactownog said:

 

PLEASE TELL ME, is the current ground enough, and should I run a ground from engine to frame up front?   

 

The current one (like Keiser's pic) is good enough for the starter. Those are the only heavy wires you need. The third heavy cable is only used on cars where the ground cable goes to the frame (not like yours).

 

The rest of the car does need to be grounded somehow, but if most or all of your lights and gauges work good it probably already is. It couldn't hurt to add one, but it wouldn't need to be a big wire like the battery cables. It might brighten things up a little, but wont make any difference on the starter. You have that covered.