1932 Rockne Hot Starting Problem

[keithb7]

Hi folks. I am posting here on behalf of a friend. He owns a 1932 Rockne. The car is currently parked for the winter. We were recently talking about it. Last summer he experienced a problem starting the car when it was hot.

There is no problem at all when cold. On a drive last summer he pulled over for a quick stop. Turned off the car. No go-go juice. His figured his battery was good, however there did not seem to be enough amps to turn the engine over. A quick boost with a

12V yielded the same results. The engine would not turn over. He called a tow truck to get home. Later it started fine when cold. He proceeded to remove the starter and have it checked over and tested at a local specialty shop. It tested fine he was told.

 

He was telling me the car's engine has about 8,000 miles on it since last rebuild.  The car has no engine oil filter. He changes the oil about every 500 miles. In another post I read about carbon build up behind piston rings possibly causing a problem.

Could that be the case with only 8,000 miles on the engine with 500 mile oil drain intervals? Maybe the starter was not looked at close enough and there is an internal grounding problem.

 

I had a crazy idea. If the car started fine cold, could it but shut off, then pull the starter. Put it in an oven at a low temp setting. Like 170F or so for an hour or so to warm it up. Then re-install (with oven mitts on! LOL) and see if the starter is the problem when warm?

Maybe thats crazy... Is there a simple way to measure starter amp draw when cold, then again when hot? Or maybe measure resistance across 2 points when cold, and again when hot to see if there is an internal issue, maybe overlooked by the starter shop?

If there was a battery problem, would the 12V boost not overcome that? Then again, maybe it depends how the 12V was hooked up. I am not sure if he went right off the starter solenoid or through possibly a bad battery.

 

Any tips on further troubleshooting  are appreciated. I can try and gather more info if required. I will pass along any ideas shared here. Thanks, Keith.

 

Here is the car for those interested:

 

Edited February 2, 2018 by keithb7 (see edit history)

[Willie Wurke]

Here is my suggestion . Find a repair shop that has a SUN BATTERY/STARTER tester.  It connects to your battery posts (same as a booster battery) 

and shows starter draw in amps.  It takes about 5 minutes . You don't have to take anything off except the battery cover; can't beat testing in situs!

. I have the tester , but my cables won't reach to your car!

 

GOOD LUCK!

[keiser31]

I would check the coil, too.

Edited February 2, 2018 by keiser31 (see edit history)

[Curti]

See post #3 in 58 Cadillac starting issues below.      

[retiredmechanic74]

I have a hand held Gage that you hold against the cable that runs down to the starter and while cranking will show how much amperage is being drawn while cranking. But if the engine is carboned up the starter will show more draw because of the resistance. 8000 miles has me wondering how often the car is driven. For example "every time" you start a vehicle you need to drive it 7 miles to warm it up to operating temperatures then another 7 miles to clean out all the hydro-"carbons", moisture, and recharge the battery. Most people don't do that, they get the vehicle all warmed up then shut it off and it sets. I don't know the habits of the driver but this is something to consider. Besides running a carbon cleaner through it won't hurt it ( as long as it is done right)   

[jan arnett (2)]

Make sure you have a good ground>  A questionable ground my work sometimes.  Just take a jumper cable and run it from the battery to the starter motor.

  

[Rusty_OToole]

Does the car have a hand crank? If so check the difference in turning resistance hot and cold. It is possible in a newly rebuilt engine that it is tightening up when hot, if certain clearances are too small. The cure may be a few long trips to break it in.

[hidden_hunter]

Does the car have a pre heat for the gas? 

[Rusty_OToole]

He is saying the engine will not turn over when hot. This is probably 1 of 2 things. 1) Engine stiffens up when hot and is impossible to turn. Since the engine was recently rebuilt, this is possible if the pistons and bearings were fitted too tight. 2) Engine turns over freely but starter system is failing. This too is possible on an old car.

 

Once we know which it is it becomes possible to figure out the cure. Otherwise you are just tearing everything apart at random and hoping for the best. I don't know about you, but this never works for me. I actually have to spend 10 minutes diagnosing the problem rather than spend 20 hours and $1000 fixing random parts that were never broken in the first place.

Edited February 3, 2018 by Rusty_OToole (see edit history)

[Bloo]

5 minutes ago, Rusty_OToole said:

1) Engine stiffens up when hot and is impossible to turn. Since the engine was recently rebuilt, this is possible if the pistons and bearings were fitted too tight.

 

This is far and away the most likely scenario. It is so easy to do because many 1930s pistons were either cast iron, or aluminum with (Invar?) supports cast in and slots to control expansion. Replacement pistons may be plain aluminum. Plain aluminum pistons, at least the full skirted type used in 1930s cars, expand significantly more than original pistons. It is a major reason they weren't used in the first place. If you set them loose enough to work, they will rattle when cold. Invariably someone will insist on setting the piston clearance to what the manual says it should be. This works fine until the engine gets warm.

 

Keep troubleshooting and hope it turns out to be the starter system.

[keithb7]

Thanks for all the tips folks. I particularly like the idea of trying the hand crank cold, then on the hot engine.  You'd surely be able to tell if the engine is tightening up.

The clamp type multimeter for measuring amp draw via conduction is a good one too. Grounds are cleaned up. Good fat cables. Probably start there and then move on through the troubleshooting.

More to come later. Appreciate the ideas.

 

[Guest]

Did you rebuild the starter when you rebuilt the engine.  They should always be done together.  In the 14 years that I worked in a GM dealership we had at least two dozen times every year when a person wouldn't pay to have the starter overhauled at the same time and then had to come back because of hard starting.  Maybe not the problem here but something for everyone to remember.

[Curti]

Very often a rebuilt starter is : New brushes, bearings , bendix, maybe turn the commutator, a fresh coat of paint.  The grounding brushes are still grounded to the end plate with he 70+ year old corroded rivets . The initial problem will still exist.

They will test OK with a meter, but 600+ amps trying to crank a fresh hot engine, it needs all the grounding it can get.

[jan arnett (2)]

You could also pull the plugs when hot to eliminate compression from the equation.

 

[rbk]

A common problem is that the armature racks up on the stator when hot.

The problem is that the bushings on the armature shaft are worn and when the armature is

hot and expanded and the play in the bushings allows the armature to touch the stator and that 

slows down the starter.

That condition is worse on Delco starters.

On Delco starter sometimes the insulation on the armature swells up and slows down the starter when it touches the stator.

You should post this on the Studebaker forum.

Rockne was build by Studebaker and they used the same starters.

http://forum.studebakerdriversclub.com/forum.php?s=f1098def6d02fada8971c02cfe177f92

 

http://forums.aaca.org/forum/21-studebaker-erskine-rockne/

 

Edited February 4, 2018 by rbk (see edit history)

[Rusty_OToole]

On 2/2/2018 at 9:05 PM, Bloo said:

 

This is far and away the most likely scenario. It is so easy to do because many 1930s pistons were either cast iron, or aluminum with (Invar?) supports cast in and slots to control expansion. Replacement pistons may be plain aluminum. Plain aluminum pistons, at least the full skirted type used in 1930s cars, expand significantly more than original pistons. It is a major reason they weren't used in the first place. If you set them loose enough to work, they will rattle when cold. Invariably someone will insist on setting the piston clearance to what the manual says it should be. This works fine until the engine gets warm.

 

Keep troubleshooting and hope it turns out to be the starter system.

Here is an old trick. Fit the pistons "loose" or to the recommended clearance. Then knurl them to fit tighter. I got this tip from a fifties Hot Rod magazine. Their technical editor drove a Corvette with a hopped up 283. He used solid skirt forged aluminum racing pistons, fitted to the recommended .012" clearance but had them knurled. Said he had 30,000 miles on it and no problems with piston slap or wear.

[Bloo]

46 minutes ago, Rusty_OToole said:

Here is an old trick. Fit the pistons "loose" or to the recommended clearance. Then knurl them to fit tighter. I got this tip from a fifties Hot Rod magazine. Their technical editor drove a Corvette with a hopped up 283. He used solid skirt forged aluminum racing pistons, fitted to the recommended .012" clearance but had them knurled. Said he had 30,000 miles on it and no problems with piston slap or wear.

 

I know guys used to do that trick to prevent scuffing in race engines, the knurling gives the oil a place to sit. It seems to me, though. that the expansion would just knock down the knurling to whatever the clearance really needed to be, and the noise would come back. I guess it would be as tight as it could be.

 

I think it might be hard to find anyone to knurl pistons these days. I got some blank looks for suggesting it even in the 80s.

Edited February 5, 2018 by Bloo (see edit history)