CCKW - Slow Cranking

[Vulture]

Guys, I feel the engine is cranking over too slowly on start-up (from cold). That said I've only heard a couple of others start up, so I'm looking to those more knowledgeable to share their thoughts please.

 

Points to note:

- It's a 6 volt system.

- The battery was new last Jun.

- The battery was fully charged.

- I've cleaned the battery terminals recently (it made no difference)

- I've cleaned the connection on the earth strap on the chassis recently (it made no difference).

- I've cleaned the connection on the starter switch yesterday (it made no difference). (Condition of bolt 'poor').

- I pulled back the metal band and inspected the contacts. Armature is clean and the contacts look almost new.

- I didn't expect the engine to start on this crank, as the choke wasn't out and I hadn't pumped the accelerator.

- Lubricated the end bearing recently.

- No idea when the starter was last removed and the front bearing lubricated.

 

I'm planning to buy a multimeter to do a resistance check on the wiring.

 

[video=youtube_share;qAThZyilRXs]

 

 

Ideas, comments, observations ?

 

As an aside,

1. What do you use to lubricate the starter linkage ? The TM doesn't say (unless I'm missing it).

2. Anyone have a diagram or photos showing the inside of the switch ?

 

Kind regards to all

 

Vulture

Edited May 5, 2012 by Vulture
Spelling

[N.O.S.]

That's respectable - couldn't say mine was that much different.

 

You've done all the right things. The starter solenoid contacts and plate must however be spotless for best performance. On some bigger starters I've cleaned them up as best I could but a new set has improved the situation. If the battery isn't 100% it will have a dramatic effect on starter performance. That said if everything else is ok it will still start.

 

We had an old CMP Chev at work - if it just went Woouuggh...(1 second delay)....Woouuggh (and it never turned over any faster) it would burst into life (well on 4 of 6 anyway :cool2:).

 

When you put the meter on, don't be surprised to measure only 3 or 4 volts at the coil when cranking - the starter grabs everything else.

[Pete Ashby]

Vulture read through this thread some of the discussion is relevant to your question http://hmvf.co.uk/forumvb/showthread.php?30857-Jeep-conversion-to-12v-(I-finally-got-fed-up-with-6v-!!).

 

Listening to your video clip the cranking speed does sound a little slow to me. I think I can hear the motor stalling as it comes up on compression for each cylinder, this could be due to a whole heap of issues as you will see in the thread above. If you are certain that your feed and earth are up to standard I would start to look at the starter motor bushes and bearings. Worn bearings and or bushes can produce that stalling effect as the cylinder compression builds the torque on motor shaft increases. Worn bushes/bearings will then let the shaft twist this has the effect of pulling the starter dog deeper into mesh with the ring gear and in effect stalls the motor. I am assuming that you are sure your static engine timing is correct by the way.

 

Pete

[Enigma]

I had a 6 volt system om a Dodge.

It turned over very slowly (about once a second).

The fault was a faulty startermoter, it was a NEW one!

[griff66]

need bigger amp battery!! or fit cardboard to rad!

Edited May 5, 2012 by griff66

[Tony B]

Clean all contacts absoultley bright and make sure everything is tight.

[deadline]

Dielectric grease on all contacts. Better conductivity and stops corrosion.

 

Take starter to starter shop and have them put it on the growler and test the armature.

 

Have the bushings/bearings been looked at? If the wear is bad enough the armature could be rubbing the field coils, of the shaft my bind. The starter gear SHOULD be getting 100% mesh.. no less than 50%. You can check tooth wear or use leaded paint to see the tooth pattern. More contact is better!

 

A simple test:

 

Take out your spark plugs and test the starter. If it spins the motor faster then you LIKELY have an electrical issue. If the if spins the motor the same slow speed you LIKELY have a mechanical issue.

 

For a starter motor you don't use cardboard.. that is crazy. For starter motors you use butchers paper. I'm surprised I had to post that. :laugh:

[R Cubed]

 

Guys, I feel the engine is cranking over too slowly on start-up (from cold). That said I've only heard a couple of others start up, so I'm looking to those more knowledgeable to share their thoughts please.

 

Points to note:

 

- It's a 6 volt system.

 

Not really a problem.

 

- The battery was new last Jun.

 

Good

- The battery was fully charged.

 

Good

- I've cleaned the battery terminals recently (it made no difference)

 

good, use boiling water to dissolve any corrosion on the battery terminals (don't burn yourself), then apply a good helping of Vaseline to all electrical connections, Battery and also the starter motor connection.

- I've cleaned the connection on the earth strap on the chassis recently (it made no difference).

 

Good, need to do battery neg to chassis and also the earth straps between the chassis and engine ect, they do need to be down to bright bare steel on the chassis and a good clean copper colour, or tinned colour on tinned earth straps, then good helping of the Vaseline all over the joint then bolt up tight.

- I've cleaned the connection on the starter switch yesterday (it made no difference). (Condition of bolt 'poor').

 

Not so good, again joint needs to be clean and tight. Cover with Vaseline.

- I pulled back the metal band and inspected the contacts. Armature is clean and the contacts look almost new.

 

Should be.

 

- I didn't expect the engine to start on this crank, as the choke wasn't out and I hadn't pumped the accelerator.

 

What is the concern with slow cranking ? does it sometimes not start, it is only 6 volts don't forget !!!! Thats about as fast as I have heard others truck turn over.

- Lubricated the end bearing recently.

 

Should be a regular thing

- No idea when the starter was last removed and the front bearing lubricated.

 

remove starter and grease all moving parts, not too much though you don't want it all flying off over the clutch !!!

 

I'm planning to buy a multimeter to do a resistance check on the wiring.

 

You don't want to carry out a resistance test on the wiring. You need a voltmeter, connect one voltmeter lead to the battery POS + term the other lead of voltmeter to the next POS + connection down the line, you are looking for a reading as near to "0 zero" as possible this proves there is little resistance (ie no volt drop) can also be done when cranking the starter, this will prove the wiring between the battery and the starter. Once this is done you can follow this on all the way and also check other wiring like lights ect.

You can also use the voltmeter in the conventional way ie: connect black lead to NEG - and then with the red lead poke around the coil feed is important you need as many volts at the coil + as possible ( the more volts the bigger the spark )

From the starter there is a wire which goes up to the AMMETER then on to the ignition switch then on to the coil lots of points to lose valuable volts, as NOS said don't expect to see much more than about 3 to 4 volts at the coil when cranking, the starter on load when cranking draws about 350 AMPS, I know I have load tested my truck :wow:

 

Ideas, comments, observations ?

 

As an aside,

1. What do you use to lubricate the starter linkage ? The TM doesn't say (unless I'm missing it).

2. Anyone have a diagram or photos showing the inside of the switch ?

 

Kind regards to all

 

Vulture

 

1. All kinds of linkage should be regularly greased to prevent wear at contact points where rods pass through plates and bushes ect. Such as all the link rods connecting the leavers in the cab with transfer box ect, Good saying if it moves grease it.... cant go far wrong with that..

 

2. The inside of the starter switch on the top of the starter is like 3 triangles should look a bit like this.

 

Edited May 7, 2012 by R Cubed

[N.O.S.]

..........What is the concern with slow cranking ? does it sometimes not start, it is only 6 volts don't forget !!!! Thats about as fast as I have heard others.....

 

I'm beginning to think we're in a minority :laugh:

[deadline]

Vaseline is a poor choice. Its dropping point is 40-60C. That means it will 'melt away' on a warm day with the engine running. It also has very poor adhesion.

 

Vaseline Grade: Pharmaceutical Grade. Dropping Point: 42-60℃

 

Dielectric grease:

Drop Point (ASTM):

 

Temp. Range: -70.0 °F [Min], 400.0 °F [Max]

 

 

You only need a drop of Dielectric grease so a small tube goes a LLOONNNGGGGG way.

 

A health starter only pulls 65 amps no-load at 6 volts, 6000RPM. Any electrical motor shop should be able to test that.

 

 

Obligatory TM citation.

[R Cubed]

I'm beginning to think we're in a minority :laugh:

 

I am sorry to say I started getting lots of high resistance joints through the ignition switch ect started to get troublesome starting and this coupled with wanting much better lights I went for 12 volts, not looked back, kept the 6 volt starter though, poor old engine does not get the option of not starting as it turns over so fast it has to start.

 

Also handy for over taking up hill just push the starter button and woooosh you have passed every thing :cool2: Sorry only kidding.....

[rosie]

 

Also handy for over taking up hill just push the starter button and woooosh you have passed every thing :cool2: Sorry only kidding.....

Ha ha ha ha ha!!!!!!!!!! That made laugh out loud!!!!! Can just imagine you 'zooming' past every one on a hill with the 105 bumping about behind you!!!!!!! Guess you can always dream hey?!!!!!

[Bran D]

As an owner of post war British I am amazed at anyone stating with 6 volts on a large-ish petrol engine. 24Volt does even more than 12volt...! Seriously though, as in the first post vulture said he was considering a multimeter to check the resistance of the wiring, this would not prove anything. A modern mulimeter is such a high impedance that it does not help with this type of reading. What you can do is check the voltage drop between the battery earth and the engine starter earth whilst cranking the engine over. Anything over 0.5 volts can be enough to cause an issue. Just measuring the resistance does not tell what is happening when the starter is drawing lots of amps. Check the voltage drop across several of the starter cables whilst cranking and you might see where the problem is. At high cranking current a high voltage is equivalent ( more or less) to a high resistance across a cable or connector. The trouble is cheap modern multimeters do not help with fault finding on high current drawing systems, or systems when a lot of spikes or interference is present.... just as happens on old vehicles. With a cheap multimeter I’ve seen 400 v dc recorded on a healthy 12 volt charging system, just down to the spikes on the charging circuit. An old fashioned moving coil meter would not show this problem, it’s very difficult to work with modern high impedance multimeters on old, electrically noisy systems so some interpretation and experience is needed.

So I guess in the case of this slow turning engine, don’t rely on new multimeters but follow the tips suggested earlier.

[Degsy]

Ha ha ha ha ha!!!!!!!!!! That made laugh out loud!!!!! Can just imagine you 'zooming' past every one on a hill with the 105 bumping about behind you!!!!!!! Guess you can always dream hey?!!!!!

 

Don't know about dreaming, wait 'til he's got that new set up sorted:drive:

[deadline]

Most analog 12V multi test sets will work fine with 6V. Things like 12V strobe lights, RPM/Dwell/volt meter combos work fine on 6v.

 

6V is completely CAPABLE of starting a big 270. But you have to tend to it. 12V buys you a lot of 'sloppyness' in the system. You don't need super clean grounds, you don't need super thick cables.

 

Most of the slow starting issues are simply (sorry guys, but its truth time) poor maintenance. Do you have commutator stones to clean the commutators? What about a scale to check the brush tension? Is the commutator out of round? When have you last added a few drops to the oil port on the rear starter housing? Or remove it to oil the Outboard bearing (hint: 1000 and 6000 miles, respectively but I would do it every month or two... a sitting bearing can drain out the oil).

 

Those are everyday questions for a mechanic when working on antique cars. There are no OBDC codes, and you have to rely on TMs and common sense (and know a mechanic or three... two will never agree so you'll need a tie breaker).

 

Spend the time to go over the starting circuit. Repair/replace what is out of spec and you'll be starting on the 1st or 2nd revolution.

[N.O.S.]

.......... and you'll be starting on the 1st or 2nd revolution.

 

See post # 2 :-D And it had two valves missing :shocked: But yes, what you advocate makes good sense :thumbsup:

[JonP]

Just to add my 353 turns over slowly on 6V.. its what I expect. I must admit it does turn over fairly consistently though. I pull the drive button out about 1/2" (as per the TM starting instructions).

 

What is the capacity of your 6V battery? Larger capacity will allow you to crank for longer?

 

I used to have starting troubles but since I got a larger capacity battery and pull out the drive button she (touch wood) starts more or less after 3-6 seconds... the TM also talks about cranking up to around 20 seconds before taking your foot off the starter button. Btw I am starting from cold directly on LPG! Yes, LPG (I know normally you start on petrol then switch to LPG).

 

There is a nack to starting our truck.. but reading the instructions in the TM has helped improve the success rate at first time starting (easy to think starting an old vehicle is a 'simple' task)

 

Jon

[deadline]

Missing a valve or two? Have you tried cardboard? :laugh:

[N.O.S.]

Cardboard? There was no point in using cardboard - it never had any water in it :rofl:

 

You had to get it to where you needed to use the welder or cutting gear it carried within 4 minutes, otherwise it would seize up and you'd have to let it cool down.

 

Brilliant truck - C15A. Will be selling it for spares soon. The gearbox is in my M6, the axles will be like new inside I expect if they are the same as the gearbox But I wouldn't imagine the engine will be a lot of good :whistle:

[Tony B]

Having been rapidily introduced to starting a six volt in the worst of circumstances. Vehicle sitting for about two years since starting , with a reputation of being a bit of a cow before that, and an ualterable set time table to move. I don't see the problems! After a couple of gallons of fresh fuel , a decent battery the old girl fired up a treat. I had to play the choke a bit, but I've come to the conclusion she is running rich anyway. When I got home I changed the dizzy cap, very worn, the rotor arm , equally worn, much less problem. Follwing that a bit of emery on the points , re-set and a new condensor, she is starting very easy from cold and hot. So empirically the system will work anyway despite a lot of disadvantages, but when it set up right, no diffrence from a 12 volt system.

[Vulture]

Having been rapidily introduced to starting a six volt in the worst of circumstances. Vehicle sitting for about two years since starting , with a reputation of being a bit of a cow before that, and an ualterable set time table to move. I don't see the problems! After a couple of gallons of fresh fuel , a decent battery the old girl fired up a treat. I had to play the choke a bit, but I've come to the conclusion she is running rich anyway. When I got home I changed the dizzy cap, very worn, the rotor arm , equally worn, much less problem. Follwing that a bit of emery on the points , re-set and a new condensor, she is starting very easy from cold and hot. So empirically the system will work anyway despite a lot of disadvantages, but when it set up right, no diffrence from a 12 volt system.

 

What sort of cranking speed do you have, compared with mine ?

[Tony B]

Compared to my 12 volt Dodge it does seem a bit slow. I'd say roughly half the speed of the 12 volt. Possibly slightly faster than yours. Thing is we aren't talking a Disiel here if the piston and the spark at the right place and time it should go. Think of hand crancking that has to be slower than a starter motor. I know the system was in poor condition when I started . Katy has done more milage in the last three days than she has in the last five years!

[Brooky]

Only just caught up with this thread

The GMC I had spun at about that speed, and you do think the thing will never start!!!

 

However in your clip I would really have expected the engine to start given the time you were trying

 

The thing I found was that you had to keep the ignition system and fuel system in tip top condition to give the slow starter a chance

 

Have you tried to start it on the handle, it should really start after going over a couple of compressions

[Vulture]

Only just caught up with this thread

The GMC I had spun at about that speed, and you do think the thing will never start!!!

 

However in your clip I would really have expected the engine to start given the time you were trying

 

The thing I found was that you had to keep the ignition system and fuel system in tip top condition to give the slow starter a chance

 

Have you tried to start it on the handle, it should really start after going over a couple of compressions

 

 

Hi Brooky

 

Thanks for your thoughts. Its seems that slow cranking with a 6volt system is the norm, and that my cranking speed is not too out of the ordinary. I didn't expect the engine to start, as like I say I hadn't pulled the choke out, adjusted the hand-throttle, or pumped the accelerator.

 

Mine is the b1 model so I have a winch right in front of where the starting handle fits. To use the handle you have to unwind the winch.... :nut:

 

I'm going to get some checks done on the plug leads to make sure they are not breaking down, they look pretty old it has to be said...

 

Kind regards

 

Vulture

[Brooky]

Hi Brooky

 

Thanks for your thoughts. Its seems that slow cranking with a 6volt system is the norm, and that my cranking speed is not too out of the ordinary. I didn't expect the engine to start, as like I say I hadn't pulled the choke out, adjusted the hand-throttle, or pumped the accelerator.

 

Mine is the b1 model so I have a winch right in front of where the starting handle fits. To use the handle you have to unwind the winch.... :nut:

 

I'm going to get some checks done on the plug leads to make sure they are not breaking down, they look pretty old it has to be said...

 

Kind regards

 

Vulture

 

Fair point

Mine had a workshop body (it used to live on Houghton Hill) and the battery was in the body, if it wasnt going to start I used to use the 12V battery I had to run the lights to jump start it!!!

 

It used to start then

 

The secret I think is to make sure every thing ingnition wise is spot on and have a decent 6V battery

Any vehicle with 6V system sounds lazy, you only have to hear a Ford 7V trying to start