Starter will not turn motor

[gnarlycreature]

Hey guys, I've been finishing someone else's project I purchased two years ago. I'm new to this forum, but I've been a stove bolt member for a few years now. I've been having some starting/ motor turning over issues, and I was wondering if you guys can help put together the issue at hand.

There are a lot of unfinished threads with no exact answer, but I have found consistent information on lawn mower and tractor forums( about the same engine right? ��)

The problem:

Motor will not turn over with plugs installed. Motor spins freely with plugs removed.

This is consistent with 12v jump and 6v power.
Belt removed


It's a 1954 Chevrolet 3600, with the 235.

Important information:
The truck is still 6v (new harness)
It has a 55 or later flywheel( 168 tooth )
It has a freshly rebuilt 6v starter with a 12v bendix and armature
New Optima Red Top 6v
4 Gauge Battery Cables


4/26
Adjusted Valves to mechanical specs of .006 intake, and .013 for exhaust

Upgraded to new grounds/ and starter wire 2/0 wire
Freshly ground frame contacts and used dielectric grease

Jumped the starter with 12v battery still won't turn over.


The previous owner "apparently" rebuilt, or at least resealed the motor.

Possible causes?

Thicker Gauge Battery Cables
Adjusting the Valves
Bad Starter
Bad Engine(stuck valves?/ bearings etc)

Lwt me know what you guys think!
Posted via Mobile Device

[gnarlycreature]

Originally Posted by gnarlycreature

Hey guys, I've been finishing someone else's project I purchased two years ago. I'm new to this forum, but I've been a stove bolt member for a few years now. I've been having some starting/ motor turning over issues, and I was wondering if you guys can help put together the issue at hand.

There are a lot of unfinished threads with no exact answer, but I have found consistent information on lawn mower and tractor forums( about the same engine right? &#128514

The problem:

Motor will not turn over with plugs installed. Motor spins freely with plugs removed.


It's a 1954 Chevrolet 3600, with the 235.

Important information:
The truck is still 6v (new harness)
It has a 55 or later flywheel( 168 tooth )
It has a freshly rebuilt 6v starter with a 12v bendix and armature
New Optima Red Top 6v
4 Gauge Battery Cables




The previous owner "apparently" rebuilt, or at least resealed the motor.

Possible causes?

Thicker Gauge Battery Cables
Adjusting the Valves
Bad Starter
Bad Engine(stuck valves?/ bearings etc)

Lwt me know what you guys think!
Posted via Mobile Device

Posted via Mobile Device

[55dude]

check the grounds! pull the plugs and check the difference.

[Kim57]

You say it turns freely without the plugs in but wont when they are installed.
Sounds like to much compression for the starter motor to overcome.
May be a bad starter or a weak battery.
I would try jumping it to see if that helps.
Kim

[Jemezcrusher]

I would pull the plugs back out and run a compression check. This would let you know if the valves are adjusted/working properly. Need o make sure the timing is correct too. You can get it pretty close with #1 at TDC and rotor aligned at TDC.

Make sure you have a good ground going from the engine to the chassis as well as the body. If all the above checks out and still no result, I would suspect the starter

[svr]

Get a hand held volt meter that measure volts down to tenths. have some one try to start it while you hold the leads on the starter battery terminal and the starter frame. If battery and connections are good it should read 6 volts with out the starter trying to run and shouldn't drop more than a volt when the starter tries to run. If it drops more than that you don't have good connections or a weak battery. If it doesn't drop much and still won't turn the motor, I would pull the starter and have it checked.

[starterman99]

6 volt uses heavier battery cables than your 4 gauge cable. They should be heavier and as short as needed, extra long cables will only make it crank harder.

[oldbritishcarnut]

In your post you say that it has a 12V bendix and armature, I think that is your problem in that you essentially have a 12V starter now. Have you tried cranking it with a 12V battery?

[1project2many]

There are a lot of unfinished threads with no exact answer, but I have found consistent information on lawn mower and tractor forums( about the same engine right? ��

Not at all but maybe not due to the reasons you are thinking of. Many lawnmower engines are designed with cam lobes that reduce cranking compression. When the valve adjustment is wrong in these engines the "compression release" function does not work. Ignition timing on a small engine has little to no ability to change with RPM so spark occurs much earlier than in an automotive engine. The combination of higher advance and high cranking pressure prevent the starter from turning the engine over effectively. Our truck engines do not have this compression release function as the gear reduction between starter and flywheel is much greater, and because the distributor has a built in advance mechanism which allows less timing at low engine speed.

In your post you say that it has a 12V bendix and armature, I think that is your problem in that you essentially have a 12V starter now. Have you tried cranking it with a 12V battery?

This is the path I would probably follow first. It's not uncommon for folks to drive a 6V starter with 12V battery. The solenoid can suffer before the starter motor so the cure is to install a 12V solenoid. In your case it seems the PO might have taken this a step further and upgraded the armature as well.

When driving the 12V solenoid with a fully charged 6V battery you are at or below the minimum voltage that will properly close the solenoid before ever applying power to the S terminal. If the solenoid closes the additional power required to drive the starter motor may further reduce what's available at the starter motor. Insufficient gauge battery cables installed with the intention of switching to 12V will only aggravate the problem. 6V systems rely on large amounts of current flow to perform work and typically use 00 or 0000 ga cables while 12V systems use 2ga to 4ga cables.

If you want to diagnose the system before replacing parts, the first check is to ensure you have battery voltage at the positive cable connection to the solenoid when the starter motor is engaged. If you have less than 5V you need to check your primary cable connections (positive and negative). If you feel any heat in the cables or at the junctions there's a very good chance you have a voltage drop to investigate. Next step is to measure the voltage at the terminal between solenoid and starter motor while 6V is applied to the S terminal. If the voltage is fluctuating or significantly lower than battery voltage you may have a problem with the solenoid engaging or an internal problem in the solenoid. If you get good voltage all the way to the starter motor the problem is likely to be in the starter itself. This is the most likely outcome imo. The 12V armature and 12V starter solenoid really do make your starter a 12V part rather than the needed 6V version.

[dsraven]

I am with the same thought process here in that your starter is essentially a 12 volt starter that is working at a 6v potential. that is why it seems to crank ok when the spark plugs are removed. voltage has been referred to as being thought of like pressure in a water hose. running a 12 volt starter with only 6 volts would e like running a sprinkler with the tap only turned on half way. I would suggest that you convert the unit to 12 volts or else get a 6volt starter. the 12 volt swap isn't that tough. below is a link to explain it better.

http://www.how-to-build-hotrods.com/6v-to-12v.html

[dsraven]

or try these. read the pro's and con's and find conversion parts

https://www.fillingstation.com/articles/6volt.htm


http://www.oldengine.org/unfaq/six12.htm


http://www.jalopyjournal.com/forum/t...9-1954.689017/


http://www.patricksantiquecars.com/c...ts.html#chevy5

[73kay]

Originally Posted by gnarlycreature

Hey guys, I've been finishing someone else's project I purchased two years ago. I'm new to this forum, but I've been a stove bolt member for a few years now. I've been having some starting/ motor turning over issues, and I was wondering if you guys can help put together the issue at hand.

There are a lot of unfinished threads with no exact answer, but I have found consistent information on lawn mower and tractor forums( about the same engine right? &#128514

The problem:

Motor will not turn over with plugs installed. Motor spins freely with plugs removed.


It's a 1954 Chevrolet 3600, with the 235.

Important information:
The truck is still 6v (new harness)
It has a 55 or later flywheel( 168 tooth )
It has a freshly rebuilt 6v starter with a 12v bendix and armature
New Optima Red Top 6v
4 Gauge Battery Cables




The previous owner "apparently" rebuilt, or at least resealed the motor.

Possible causes?

Thicker Gauge Battery Cables
Adjusting the Valves
Bad Starter
Bad Engine(stuck valves?/ bearings etc)

Lwt me know what you guys think!
Posted via Mobile Device

I thought Chevy switch to 12v and different flywheel teeth around 54-55? So if you have a 12volt flywheel with a 6volt starter regardless of 12/6 volt battery you may have teeth issues. Maybe I'm missing something but something to doublecheck.

[gnarlycreature]

Updated the first post with some changes I made. I just ran out of light for the day.
I will definitely respond to everyone, and thanks for keeps me thinking.

Today's changes:
New 2/0 gauge wire on:
Battery To Ground
Battery to Starter
Frame to Motor

Adjusted Valves to mechanical specs(not sure if I have a hydraulic or mech) .006 intake, and .013 for exhaust

With Plugs in on 6v:
Disconnected belt from waterpump and generator.
Turned better, but still not spinning motor over

With Plugs in with 12v jump( 6v battery disconnected )
Similar results as to the 6v battery

[svr]

Sounds like the starter has to come out and pulled apart, brushes not right, defective windings, open in the armature, would be my next move.

[gnarlycreature]

[gnarlycreature]

I'm posting from my phone, I have to look up information on my engine when I get to a computer.

[mr48chev]

I think you hit it in the first post, that mix and match starter just doesn't have enough poop going for it to turn the engine over good enough when the plugs are in.

There have to be some good starter, generator,alternator shops in LA that can sort that unit out and let you know if it will work or not. They might also have some suggestions as to how to have one that is up to the task.

I'm wondering if the bushings might be just loose enough to let it spin the engine with no plugs and no real resistance but let the armature drag when you have a load on it.

[Black93GT]

Plugs installed... And connected to the distributor or just installed????

I fought for hours to get this 327 fired up. It would immediately stop the engine as soon as I powered the distributor. The plug wires were off by a terminal... Which baffles me how it ran when I bought the Camaro.

[gnarlycreature]

Originally Posted by mr48chev

I think you hit it in the first post, that mix and match starter just doesn't have enough poop going for it to turn the engine over good enough when the plugs are in.

There have to be some good starter, generator,alternator shops in LA that can sort that unit out and let you know if it will work or not. They might also have some suggestions as to how to have one that is up to the task.

I'm wondering if the bushings might be just loose enough to let it spin the engine with no plugs and no real resistance but let the armature drag when you have a load on it.

Bringing it back to the rebuilder today.

Originally Posted by Black93GT

Plugs installed... And connected to the distributor or just installed????

I fought for hours to get this 327 fired up. It would immediately stop the engine as soon as I powered the distributor. The plug wires were off by a terminal... Which baffles me how it ran when I bought the Camaro.

Plugs Installed. I have spark to the distributor, but I'm just trying to get the motor to turn over before initiating spark to the cylinders.

Originally Posted by svr

Sounds like the starter has to come out and pulled apart, brushes not right, defective windings, open in the armature, would be my next move.

Originally Posted by 73kay

I thought Chevy switch to 12v and different flywheel teeth around 54-55? So if you have a 12volt flywheel with a 6volt starter regardless of 12/6 volt battery you may have teeth issues. Maybe I'm missing something but something to doublecheck.

They did in 55 to the 168 tooth flywheel. The previous owner switched had modified the starter to accommodate the flywheel with a different bendix/armature.

Originally Posted by dsraven

I am with the same thought process here in that your starter is essentially a 12 volt starter that is working at a 6v potential. that is why it seems to crank ok when the spark plugs are removed. voltage has been referred to as being thought of like pressure in a water hose. running a 12 volt starter with only 6 volts would e like running a sprinkler with the tap only turned on half way. I would suggest that you convert the unit to 12 volts or else get a 6volt starter. the 12 volt swap isn't that tough. below is a link to explain it better.

http://www.how-to-build-hotrods.com/6v-to-12v.html

Originally Posted by 1project2many

Not at all but maybe not due to the reasons you are thinking of. Many lawnmower engines are designed with cam lobes that reduce cranking compression. When the valve adjustment is wrong in these engines the "compression release" function does not work. Ignition timing on a small engine has little to no ability to change with RPM so spark occurs much earlier than in an automotive engine. The combination of higher advance and high cranking pressure prevent the starter from turning the engine over effectively. Our truck engines do not have this compression release function as the gear reduction between starter and flywheel is much greater, and because the distributor has a built in advance mechanism which allows less timing at low engine speed.

Thanks for this.


This is the path I would probably follow first. It's not uncommon for folks to drive a 6V starter with 12V battery. The solenoid can suffer before the starter motor so the cure is to install a 12V solenoid. In your case it seems the PO might have taken this a step further and upgraded the armature as well.

The armature was upgraded as well, but there is a 6v solenoid on there

When driving the 12V solenoid with a fully charged 6V battery you are at or below the minimum voltage that will properly close the solenoid before ever applying power to the S terminal. If the solenoid closes the additional power required to drive the starter motor may further reduce what's available at the starter motor. Insufficient gauge battery cables installed with the intention of switching to 12V will only aggravate the problem. 6V systems rely on large amounts of current flow to perform work and typically use 00 or 0000 ga cables while 12V systems use 2ga to 4ga cables.

I have upgraded the cables to 2/0.

If you want to diagnose the system before replacing parts, the first check is to ensure you have battery voltage at the positive cable connection to the solenoid when the starter motor is engaged. If you have less than 5V you need to check your primary cable connections (positive and negative). If you feel any heat in the cables or at the junctions there's a very good chance you have a voltage drop to investigate. Next step is to measure the voltage at the terminal between solenoid and starter motor while 6V is applied to the S terminal. If the voltage is fluctuating or significantly lower than battery voltage you may have a problem with the solenoid engaging or an internal problem in the solenoid. If you get good voltage all the way to the starter motor the problem is likely to be in the starter itself. This is the most likely outcome imo. The 12V armature and 12V starter solenoid really do make your starter a 12V part rather than the needed 6V version.

Will measure the voltage drop today.

[Black93GT]

Obviously you have new cables so that shouldn't be an issue, but I would have you verify all your connections are good.

Measuring that voltage at the starter terminal simply ensures there is a connection. As previously stated, you should measure the voltage drop from the starter terminal to the battery post. But additionally, check from the block to the negative battery post too. That would indicate a weak ground in your system.