Starter Cable Smoking Hot!!

[FlakvestXIII]

So I have finally finished my 351C rebuild, but I cannot get my starter motor to turn the engine any more. At first the starter would turn the engine with enough torque but my timing was off so I never got it to idle. Also I noticed a puff of smoke come off of the starter side of the starter relay/solenoid. Now after several other crank attempts the starter does not want to turn over at all and my starter cable gets allot of amperage going through it.

-So far I have checked all grounds visually and cleaned them with a wire brush.

-I have Ohm checked all my grounds and get 1 Ohm so I figure the grounds are fine internally.

-I took the starter and battery to NAPA to be tested (they say both are good)

This test is with no load though and I still suspect my starter, for this reason;

-I have bypassed my starter relay/solenoid and ran jumper cables from the battery directly to the starter, when I do this it sounds like the starter spins but is not fully engaging and my jumper cables heat up on the negative side. (these are pretty thick jumpers too, no cheapo small gauge wire)

Does everyone agree with my thoughts of a bad starter, or is there any other advice?

 

[Don C]

Do you have a ground cable that runs from the battery to the engine block?

Your solenoid could also be bad.

 

[FlakvestXIII]

Yes my ground circuit is complete and ohms out really well. Also I know I can rule out my grounds because I ran a direct line from the starter to the battery and still had the same problem.

 

[Don C]

I would measure the voltage on the starter side of the solenoid while cranking, and compare it to the battery voltage while cranking.

 

[johnwanzel]

You mention checking all your negative ground connections but what about your positive connections? It sounds like to me that either the positive cable is making contact with the chassis at the solenoid or it's making contact on the starter body. Sometimes when you tighten the nut on the starter stud, the cable will rotate as well, sometimes making contact to the starter housing. Same goes for the starter solenoid on the apron. Hope you find the problem soon. I know how frustrating it can be but your diligence will pay off.

 

[will e]

When working properly the cables will normally get warm from cranking. Since the engine isn't turning over the energy that would move the engine has to be dissapated. I believe you are experiencing this in the form of heat.

A couple of quick questions. You said you did, at some point, get it to start and idle. Did you do the break in procedure?

Also a quick summary of the build might help. Do you have an approximate compression ratio and if not what heads are you running (open or closed), flat top or domed pistions. A cam description would help too. A high compression engine is harder to crank compared to a lower compression engine.

You said at this point it won't turn the engine over at all. I find this a bit worrisome. I would try to crank the engine over by hand with a 1/2 breaker bar and a socket on the end of the crank. It should move pretty easy for the first 10 degrees or so and then get progressivly harder as compression builds in what ever cyl is being compressed. If you cannot get it to budge with a small amount of effort you have a different issue.

Small effort is realtive I know. I would liken it to the amount of effort to pull a hand brake tight for the initial movement of the breaker bar. Once the compression starts it will get a little harder. But it is never going to the kind of effort required to break a head bolt loose for example so don't 'FORCE' it to move. If it doesn't budge clockwise then try to move it just a bit counter clockwise.

If you are willing to pull the spark plugs the entire operation will be a lot easier. I would recommend doing this. It is unlikely but you may have a head gasket leak and a cyl full of coolant. This could have happened after you turned the engine off, the pressure could have filled one of they cyls. Again, unlikely, but not unheard of.

 

[mudbilly]

^ +1

sounds like a frozen engine................

 

[piper62j]

The negative battery cable must also be grounded to the chassis and the engine block..

The engine may also be too tight for the starter.. Good information from the guys above..