6 or 8 volt - 1926 Chrysler Model 50. starting has never been great on the positive ground 6 volt system

[STJ]

I have  a 1926 Chrysler Model 50. due to family issues and moving it has sat in storage for about 10 years. I am now in a position to get it back running, starting has never been great on the positive ground 6 volt system, so I am considering going to an 8 volt. 

I have concerns about how the higher voltage will effect things like the lights which are all original, and the starter life, and will the original generator system keep it charged?

I have the lineage of this car, and I am it's 3rd titled owner, showing just under 1000 miles. 

 

Thanks Jeff

[EmTee]

If it were mine, I'd keep it 6V and fix the wiring.  Check that the battery cables are proper gauge and haven't been replaced with modern 12V versions.  Also check the condition of the starter motor bushings and brushes and solenoid.

[John_S_in_Penna]

31 minutes ago, EmTee said:

If it were mine, I'd keep it 6V and fix the wiring.  

I agree.  I've often heard it said, even by collector Jay Leno,

that these older systems didn't have problems when they

were in use back in their day.  So, if properly set up today,

a 6-volt system should be fine to operate your car.

 

Don't introduce new items and systems.  If you do, the

old manuals won't apply when you or a future owner

needs to refer to them, and everyone will have to try to

figure out the systems and whatever was changed.

[Stude Light]

Before I owned any really old cars, I had a 1939 Allis Chalmers tractor that I used for mowing my lawn (Woods belly mower). It used a 6 volt system. The starter always turned slow so I "upgraded" to an 8 volt battery and tweaked the generator output to max. The starter turned over faster but the improvement was soon overshadowed by all the negatives. The generator was just barely capable of keeping the 8 volts topped off. What do you use for a battery charger? I ended up burning out a couple of 6 volt headlights too.

 

Finally, I got smart. I went back to 6 volts, cleaned up the starter and bought some 1/0 battery cables with new ends. Never had a problem after that.

[Ben Bruce aka First Born]

Well, I agree AND  I disagree.    8V is a partial fix at best, in my opinion.  Either fix the 6V or go all the way to 12.  As EmTee said, wiring, especially battery cables, is most important. Pos or neg ground should be of no concern, I think.   

 

  I do not remember cars from that era. Probably none left that lived through those years. I DO REMEMBER during the late 1940s and 1950s needing a push or giving a push due to no start.  Batteries then, as now, would run down. Connections  became dirty, corroded. A LOT more than now, seems like.   Hence 12V.  More leeway?

 

  I like 12V.  I can make 6V reliable.  You can too.

 

  Good luck

  Ben

[Brass is Best]

Leave it 6-volt. Fix all of the other problems. Give it a proper tune up and get a new battery. It is shocking how many cars are running around on old worn out batteries. 

[EmTee]

Once the wiring is up-to-snuff, if you still have money to spend you could buy a 6V Optima battery.  People on this forum seem to universally praise their performance and longevity.  That said, I still have a regular lead-acid 6V battery in my '38 Buick and have no complaints.

[STJ]

Thanks for all the great replies. How that it has been mentioned the battery cables are newer 12 cables, every thing else is original, from looking at the size  of the cable going to the starter which is much larger in diameter than the 12 volt cables I can see why the starting has always been slow. I will update the cables and get a new batt after cleaning everything up.

[Rusty_OToole]

One more thing. 6 volt systems are more vulnerable to resistance due to dirty loose or corroded connections. Sometimes cleaning and tightening connections makes quite an improvement. Old corroded or frayed wiring can also cause excess resistance.

[trimacar]

Run a ground directly to a starter mounting bolt.  Grounding through frame was fine when car was new and nice shiny metal between rivets, not now though…

[Akstraw]

When you say starting has “never been great”, what do you mean?  The 6v starter, even when new, did not crank at the speed of a modern 12v starter, and did not sound the same.  Your car can be started with a hand crank, so the 6v starter doesn’t need to turn much faster.  If it starts the engine reliably, then it could be that it is working just fine. The purpose of the starter is not to get the engine up to operating speed, just to get the first cylinder to fire.  After that, combustion will do the rest.

[Curti]

Keep it 6 volts .  Many times the brush grounding in the starter motor is poor.  If they ground to the end plate, ground them to the starter frame. 

This has been an excelant fix for slow turning 1930's  Auburns.

[Soupiov]

I had a 1953 Chrysler hemi and it started just fine on a six volt system.  If the cables are the right gauge, the starter is good, the contacts are clean and the battery is OK  I can't imagine why you would need to upgrade anything.

[John_S_in_Penna]

Another reason not to modify:

A car with non-standard components will be harder

to sell when the time comes.  I myself wouldn't want

a car with an 8- or 12-volt system when it was supposed

to be 6 volts, since the system wouldn't have a manual

to diagnose it.

[Rata Road]

Hi Jeff I have owned a 27 Chrysler 50 (4 cylinder) for exactly one week. I have been having issues with a vibration etc but one thing the car is perfect at is starting. Hot or cold it starts first wind. It probably winds over slow, I dont know as I never get a chance to hear it before it fires up.

Its completely stock with an older 6v battery.

Moral of this story is a 6v stock system is still good enough today as it was 96 years ago if everything else on the car is working correctly. 

[kuhner]

Easy to check the voltage drop across the cable leading to the starter. One lead of you VOM on battery terminal one on the starter terminal. Watch the voltage while someone turns the key to start.  
.5 Volts or so is probably acceptable, someone may comment to the exact voltage.  
 

[pkhammer]

I have a 1949 BF Avery tractor that I restored with stock 6 volt positive ground. When I got it back together, the engine would turn over painfully slow. I thought it was because the engine was fresh and "tight". Finally figured out that all of the newly painted assembled parts were causing a very poor ground. Once I fixed the grounding issue it made a huge difference! Tractor now spins over quickly and starts immediately, so like others have said above; proper cables and clean connections are the key.

[zdillinger]

2 hours ago, pkhammer said:

I have a 1949 BF Avery tractor that I restored with stock 6 volt positive ground. When I got it back together, the engine would turn over painfully slow. I thought it was because the engine was fresh and "tight". Finally figured out that all of the newly painted assembled parts were causing a very poor ground. Once I fixed the grounding issue it made a huge difference! Tractor now spins over quickly and starts immediately, so like others have said above; proper cables and clean connections are the key.

I just did a similar thing with my 1928 Pontiac. In the process of rewooding the car, several months ago, I repainted parts of the frame that wouldn't be seen again after the new wood was put in place, and I also rebuilt/painted the rusted out battery carrier and surrounding area. More recently I stuck the ground strap back into place to test fire the car and had absolutely nothing from the battery. Even tried the new-ish Optima from my '39 Packard... nada. A couple thin layers of paint and primer between the cable end and the frame was more than enough to stop the car from doing much of anything except sit there and look pretty.

Edited March 23, 2023 by zdillinger (see edit history)

[Bloo]

3 hours ago, pkhammer said:

I have a 1949 BF Avery tractor that I restored with stock 6 volt positive ground. When I got it back together, the engine would turn over painfully slow. I thought it was because the engine was fresh and "tight". Finally figured out that all of the newly painted assembled parts were causing a very poor ground. Once I fixed the grounding issue it made a huge difference! Tractor now spins over quickly and starts immediately, so like others have said above; proper cables and clean connections are the key.

THIS!^^

 

An electrical circuit is a circle. On a starter circuit follow it all way around, from the battery, through the starter cable and back all the way through the ground side to the other battery post. Every connection needs to be clean. Imagine the electrons wanting to flow through there. If the electrical current is flowing through paint or rust, get rid of the paint or rust.

 

I am not familiar with the specific Auburn issue @Curti mentioned, but the reasoning and solution are about the same. On a typical Postwar Ford starter for instance, the ground-side starter brushes are also grounded to the rear plate. Where that rear plate contacts the starter frame, it must be clean, no paint!. Where the starter frame contacts the nose casting, also clean. Where the nose casting contacts the bellhousing or engine block, clean, and so on. all the way back to the ground-side battery cable and then to the other battery post. This is true no matter how many volts the battery has.

 

Cables must be large on a 6 volt car. 00 is commonly recommended. Wire gauge from small to large counts down. Smaller >> 6 > 4 > 2 > 1 > 0 > 00 > 000 > 0000 >> larger. Some originals were as small as 1. 12 volt cables are typically 4 and too small to work properly at 6 volts. 6 volt systems are extremely sensitive to wire size, and bigger is almost always better. 6 volt cables good enough for a show restoration are available at Rhode Island Wire. If authentic looking cable is not needed, look at any parts store that caters to farm equipment. There are a lot of 6 volt tractors still in service, and they will have the large cables (and the big straps that were often used for ground) in stock. Another possibility is to have some made. Battery stores can do this. I don't mean the ones in a mall that have every watch battery imaginable, but the sort of store that has batteries for cars, trucks, tractors, combines, buses, heavy equipment, golf carts, etc. Typically you can get cables made from either truck/bus cable (it's really stiff in 00 but indestructible), or welding cable (much easier to route, and probably the best choice, but you shouldn't be getting a bunch of oil on it).

 

Edited March 23, 2023 by Bloo (see edit history)

[Tonz]

I put an 8 volt Deka battery in my 26 model 50, it's two years old now and all is sweet. Starts first pop.

I did have trouble spinning the engine first up (a new rebuilt tight motor) so I replaced all the cables with the correct 6v ones, cleaned the connection points to clean shiny metal and routed the earth cable off one of the starter motor mounting bolts. I have heard of running another earth strap off the engine block to chassis helps.

The 6 volt system handles the extra 2 volts no worries. But ... A big BUT is there are no good 8 volt chargers available. Gladly my three brush Genny does a good job of charging. Which incidentally you can adjust up or down for winter/summer driving.

 

When this battery expires in a few years I will put  6volt in as I feel it wasn't really necessary.

PS, a 97 year old 3rd owner car showing 1000miles!!!!!

The Speedo must have clocked over a few times😆

Edited March 24, 2023 by Tonz (see edit history)

[EmTee]

The Navy would typically impose the grounding/bonding requirements of MIL-STD-1310 for shipboard installations.  Those requirements address the preparation and sealing of ground connections.  Generally common-sense, but good practice guidelines nonetheless.

 

[nsbrassnut]

Hi Jeff

 

Some additional points to ponder.

 

As others have noted, number one is to make sure that you have heavy duty battery cables. And this applies to both the power supply "hot" cable and the ground cable. Both need to be heavy duty. And in many cases adding an additional ground cable or strap from the engine (or transmission) to the frame can also help. Something to remember, most of the car operates with 6V and a total of 5-10 amps. When the starter is engaged, the amperage can be 500 to 800 amps. Heavy cables are a must to let this much current flow with minimal loss of voltage.

 

Also, you should check the voltage at two locations when cranking the engine. The voltage at the starter terminal, and the voltage at the distributor. Both need to be 5 volts or more. Low voltage at the distributor will also cause the engine to be hard to start. Sometimes this can even be seen where a car starts as the starter is being shut off. A sign of too much voltage loss in the system when cranking the engine over.

 

We found one local Essex had good voltage at the starter, but poor at the distributor. When we checked and fixed the wiring to the distributor and got good voltage there when cranking, suddenly the car would start much more easily. It used to have to be pushed 2 times out of 3 when cold to get it to start. No more pushing now.

 

Another possible item to check. Does your car have a mechanical in line starter switch or a starter relay? Many cars of this period used mechanical full voltage/current starter switches either in the floor or on the starter, such at Ford Ts and As. These switches have internal mechanical copper contacts and springs. And they have a tendency to wear and corrode internally and not make good contact for starting. Some can be taken apart and serviced, others are riveted together and take a bit more effort to open and service.  Starters with relays have fewer issues, but the relay can deteriorate with age and not work well either.

 

A voltage check at the starter and distributor will tell you quickly if the problem is electrical or internal to the starter and/or distributor.

 

Another item which can contribute to hard starting is the type of engine oil that it being used. Back then straight weight oil was most common and you needed to change the oils from summer to winter, mostly for the ease of starting. Today you can use a good multi-grade oil year around. And that can make a difference too. I also found that in some cases changing to 100% synthetic multi grade oil also helped with making the engine spin over easier and faster when cold making starting easier. The oil consumption was also reduced and the life before turning black doubled (bypass filter only). I'm using a 10W-30 synthetic multi-oil in all of my older vehicles and have been very happy with it and they do appear to start easier since I switched over too. I operate under the theory that oil is cheap, engine rebuilds aren't. So I would rather spend a bit more for high quality oil to help make the engines last longer.

 

There was a similar '26 Chrysler 6 in the local area for a while. A nice car that ran and drive well. I had the chance to buy it once, but passed. I thought about it, but really just didn't need another one and had no place to put it then either.

 

Good luck with your car.

 

Another Jeff

[dodge28]

I remember a Lawyer telling a person "never give advice for nothing"  That is all it is worth. Pay for it and he will heed. 

You got so much free advice I doubt you are going to heed any.

Harry,

[60FlatTop]

I see frequent mention of hard starting 6V cars. My first thought goes to the timing on start up. Lack of lubrication in some hidden point on a car that has been around for 100 years is very common. Or remote lubrication reserves that never make it to the point is real common. Linkages out of adjustment or sloppy. I had a Nash that was designed so old saggy motor mounts could have affected the start timing.

If it grunts and doesn't want to roll over I figure someone has already done all that easy stuff. They teach that at the general store. I want to verify that retarded spark. Check that as soon as you can.

 

On the free advice, if you are sitting at a bar talking with a lawyer and he tells you to beware of free advice and scoops up another handful of peanuts who has the wisdom?

[zepher]

I have a Pierce Arrow with a larger 8 cylinder.

It does crank slower than a modern car with a 12v system but it has never had any issues starting if everything is correct.

 

As many others have mentioned, make sure you have the proper cables, proper connections and a properly charged battery and you should be just fine.

[STJ]

23 hours ago, nsbrassnut said:

Hi Jeff

 

Some additional points to ponder.

 

As others have noted, number one is to make sure that you have heavy duty battery cables. And this applies to both the power supply "hot" cable and the ground cable. Both need to be heavy duty. And in many cases adding an additional ground cable or strap from the engine (or transmission) to the frame can also help. Something to remember, most of the car operates with 6V and a total of 5-10 amps. When the starter is engaged, the amperage can be 500 to 800 amps. Heavy cables are a must to let this much current flow with minimal loss of voltage.

 

Also, you should check the voltage at two locations when cranking the engine. The voltage at the starter terminal, and the voltage at the distributor. Both need to be 5 volts or more. Low voltage at the distributor will also cause the engine to be hard to start. Sometimes this can even be seen where a car starts as the starter is being shut off. A sign of too much voltage loss in the system when cranking the engine over.

 

We found one local Essex had good voltage at the starter, but poor at the distributor. When we checked and fixed the wiring to the distributor and got good voltage there when cranking, suddenly the car would start much more easily. It used to have to be pushed 2 times out of 3 when cold to get it to start. No more pushing now.

 

Another possible item to check. Does your car have a mechanical in line starter switch or a starter relay? Many cars of this period used mechanical full voltage/current starter switches either in the floor or on the starter, such at Ford Ts and As. These switches have internal mechanical copper contacts and springs. And they have a tendency to wear and corrode internally and not make good contact for starting. Some can be taken apart and serviced, others are riveted together and take a bit more effort to open and service.  Starters with relays have fewer issues, but the relay can deteriorate with age and not work well either.

 

A voltage check at the starter and distributor will tell you quickly if the problem is electrical or internal to the starter and/or distributor.

 

Another item which can contribute to hard starting is the type of engine oil that it being used. Back then straight weight oil was most common and you needed to change the oils from summer to winter, mostly for the ease of starting. Today you can use a good multi-grade oil year around. And that can make a difference too. I also found that in some cases changing to 100% synthetic multi grade oil also helped with making the engine spin over easier and faster when cold making starting easier. The oil consumption was also reduced and the life before turning black doubled (bypass filter only). I'm using a 10W-30 synthetic multi-oil in all of my older vehicles and have been very happy with it and they do appear to start easier since I switched over too. I operate under the theory that oil is cheap, engine rebuilds aren't. So I would rather spend a bit more for high quality oil to help make the engines last longer.

 

There was a similar '26 Chrysler 6 in the local area for a while. A nice car that ran and drive well. I had the chance to buy it once, but passed. I thought about it, but really just didn't need another one and had no place to put it then either.

 

Good luck with your car.

 

Another Jeff

A little off the topic, my 26 has no oil filter and I have always been under the impression that one should use non-detergent oils on engines with out filters as in small mowers air compressors and the like. Any thoughts on non-detergent in the old cars or just use multi grade and change it often?

[STJ]

Thanks for all the great and FREE advice, I will be going trough the electrical system from end to end checking cable sizes and clean connections. My car does have a floor starter switch that I will lookin to.  I am mostly a vintage motorcycle restorer (early 70s motocross bikes, not a lot of electrics on them) so vintage car seen is a little new to me, thanks for all the help.Sorry I have no idea now to make the pics come out correctly.

Edited March 26, 2023 by STJ (see edit history)

[SC38dls]

Now that’s turning a car over! 
dave s 

[Ozstatman]

6 hours ago, STJ said:

 Sorry I have no idea now to make the pics come out correctly.

Look fine to me here "downunder".😉

[wayne sheldon]

Glad to see that you are going to heed the free advice! Free or not, almost everything said has been good advice!

As an additional. It is almost always better to fix something that is not working properly rather than giving a quick patch and hope!

 

As a bit of understanding the "how and why" of the six or twelve volt issue? Bad connections due to paint or rust or other corrosions, looseness, undersize wiring etc etc etc, drop voltage in a non-intuitive way. A given bad connection (or undersize wire?) will drop voltage very close to the same voltage amount regardless of six or twelve volts. In other words, a given rusty connection will drop the voltage say one volt, regardless (with a bunch of complicated exceptions!) whether there is a six or twelve volt battery installed. So with a six volt battery, that connection dropping the voltage to five will be a nearly twenty percent drop! With that same one volt drop, a twelve volt battery will lose only about ten percent of its voltage. An eight volt battery will also drop about one volt, leaving it still above the six volt threshold. Hence why an eight volt battery might work okay as a patch. 

However, not correcting the actual problem (the bad connection!) can still result in other problems or future failure. Hence, better to find it and fix it.

Wire size AND LENGTH are another complicated calculation. Suffice to say that more voltage works better using smaller wires. One of the main reasons automobile manufacturers switched to twelve volts was that the smaller wire in millions of cars saved the manufacturers millions of dollars! Also one of the reasons switching a six volt car with problems over to twelve volts SEEMS to work. However, again NOT fixing the actual problem (bad connections!) will often lead to other issues or future failure.

 

I highly recommend you read Hemi Joel's great thread on road testing his Woodlites! Link;

 

https://forums.aaca.org/topic/394480-road-testing-woodlites/#comment-2509483

 

As others have said quite well, A properly sorted six volt electrical system should work wonderfully!

 

One last thing. A sometimes great way to find bad connections? If you promise to be a bit careful? 

After the car has sat for an hour or more, start it, maybe three or four times. Then quickly, before temperatures can migrate away, run your fingers over every inch of wire you can reach, and touch every connection! SOMETIMES, often a bad connection will get hot enough for you to feel it. That alone isn't adequate to properly sort the entire system, as only some of the worst spots might be hot enough to feel.

Why do I say be careful? Because I still have a scar on my left index finger from finding a bad connection on one of my modern cars almost fifteen years ago! That silly bad connection had driven me nuts for over a month! It would only act up when I was in a hurry, and couldn't take a few minutes to find it. All I had to do was slam the hood and it would fire right up. And when it was making connection, it didn't get hot enough to feel it. Finally, one day, it acted up when I wasn't in a hurry. And I quickly found it. Oh BOY did I find it!

Over the decades, I found a lot of bad connections that way! Usually without getting burned.

[nsbrassnut]

Hi STJ

What oil to use in old cars is a bit of a “hot topic” item.   :^)

If you were to Google “antique car engine oil AACA forum” you would likely get a few hundred posts and opinions on what to use or not use.

Anyway, here is my understanding and history that I have learned so far.

Back when detergent oils were first introduced (50’s??) they had a higher detergent content than today. And at the same time, many engines ran oil with no filters and few oil additives and often would get coated with sludge inside the engine with use. Then when the oil was changed to detergent oil and the engine pan was not cleaned out, it sometimes did break up the sludge and put it through the engine sometimes resulting in damage such as plugged filters or oil lines. So yes, for a time changing over to detergent oil could cause problems.

 

However newer oils have a different set of additives and are designed to hold contaminants and dirt ins suspension with the aim of having them filtered out in the oil filter. Modern full flow oil filters are good at this.

 

Multi-grade oil is better than straight weight oil for most old cars. The multi-grade oil is carefully designed and manufactured so that it will hold a more constant actual viscosity over a wide temperature range. Keeping the oil low viscosity when cold and thicker when it warms up. This helps to make engine cold starting easier through a wider range of operating temperatures and also allows the use of one blend of oil throughout the full year.

Synthetic oil is still made from oil, but with a more involved manufacturing process that produces a more consistent molecular blend of oil. Synthetic also in most cases has a higher temperature rating before it will form carbon deposits. This difference can be up to 100 degrees F or more depending on the oil. With our vintage cars not having oil coolers that oil can still run hot in the oil pan, I like synthetic for its higher temperature rating. In my experiences, synthetic oil takes longer before starting to turn black than regular oil when used in engines with no oil filter or bypass oil filers. I like it enough that all my old cars are using synthetic oil, even those with no filter and total loss oil systems. My ’05 Cadillac has a total lost oil system that uses about 1 quart per 60 miles of driving. But it still gets 10-30 synthetic in the oiler.

For any engine that I don’t know the history of I will drain the oil then drop the oil pan and clean out any sludge or dirt deposits and replace the oil before any attempt to start the engine. More than once I found a lot of sludge in what was supposed to be a “rebuilt” engine.

So if you don’t know the history and condition of the inside of your engine, its would be a good idea to drop the pan for cleaning and inspection before changing over to any modern detergent oil blend.

And if you don’t have an oil filter on the engine, changing the oil around 500 to 1000 miles or annually is a good idea. I have seen recommendations to change the oil in the fall just before putting cars away for storage as the ideal time to do it. Myself it might be closer to every second year as it can take that long for some to accumulate 500 plus miles. Or change it when the colour starts to turn black.

Pretty much any modern quality multi-grade oil available today is better than what was available before 1940. And using synthetic is just another step up the quality ladder. As I said before, oil is cheap, engines are expensive. So, use good oil for longer engine life.

Good luck with your car.

 

Jeff