The Ford Barn

scicala · 08-13-2023, 05:15 PM

Will the points arc to the point of doing damage to the contacts, if I disconnect the condenser wire to try and diagnose a bad condenser ?
It would be run for maybe 5 minutes tops.
The car is a '55 272 updated to 12 volts with a ballast resistor.
Stock distributor.

Thanks, Sal

cadillac512 · 08-13-2023, 05:35 PM

It will be a bit hard on the points but won't destroy them. If they're in good condition a light dressing with fine emery cloth or a points file will make sure the faces are good. You probably won't even need to do that.

Terry

Daves55Sedan · 08-13-2023, 06:32 PM

'55 Ford car ignition condenser, 6-cyl or V8
.21 - .25 microfarads; minimum leakage 10 megohms; maximum series resistance 1 ohm; for use with standard 6 volt ignition coil, 1.5 ohms resistance.
HOW TO TEST A CONDENSER
1.) Remove the condenser from the engine (or at least disconnect the lead wire). Note the small metal connector located on the end of the condenser. This connector is the "hot" or power connection. The metal case of the condenser is the grounding point. Discharge the condenser by shorting the lead wire to the case.

2.) Switch the meter to the ohms position. Place the red lead into the "ohm" connector on the meter. Insert the black lead into the "com" or common connector on the meter. Set the resistance range to the highest available setting (if it is selectable). Connect the test leads together and zero the meter. If the meter won't zero replace the battery. (Yes, an ohm meter has a battery).

3.) Touch the red lead to the hot connector on the condenser. Place the black lead to the metal case on the condenser. The meter's needle should jump slightly to the right (toward 0-ohms), then should drop back to the left towards infinite resistance). Hold the leads in place for 15 to 20 seconds. This action places charge in the condenser. If the test shows any reading other than infinity, the condenser is leaking and needs to be replaced.

4.) Remove the leads and reverse the placement to the condenser. Move the red lead from the hot connector to the metal case and move the black lead from the metal case to the hot connector. At the moment where both leads are touching the correct points, the meter should jump towards the right. The second time the needle may move twice as far, as this action discharges the condenser. Holding the leads in contact should again result in movement of the needle back toward infinite resistance.

5.) Movement of the meter's needle indicates the condenser is good. If no movement was indicated on the meter in any circumstance, the condenser is bad and must be replaced. Retest the condenser several times for a consistent reading.

In operation the condenser will "ring" at up to 300 volts, so the condenser needs to be rated much higher, no less than 600 volts DC. The ignition will likely work with any capacitance value between 0.05 and 0.6 microfarad. Too high or too low value may eventually transfer metal from one side of the contact points to the other side leaving a pit and a point. Capacity of spark coil capacitors ranges from 0.2 microfarad to 0.33 microfarad. Almost all automotive coils use a 0.25-0.29 microfarad capacitor.

A capacitor may absorb moisture over a long period of time, and moisture can cause failure of the condenser. So it is possible that a condenser stored for 10 years or so might be bad or might fail prematurely in service. It is a good idea to check your traveling spare condenser occasionally.

HOW IT WORKS
Current flows through the points when they close. When they open the inductance of the ignition coil tries to maintain that current so an arc will be struck between them until the points open up enough to break the circuit. The more current you run through the points, the harder it is for them to break the current.

That is why point systems have a condenser (called a capacitor in any other electrical system). The condenser slows down the reaction time of the coil to allow the points time to open and break the circuit. Without a condenser you will likely never break the primary current and get no spark from the secondary. Having a condenser that is too large will completely prevent arcing across the points but will also slow the coil so much that it is unable to strike an arc on the secondary. The trick is to find a condenser that gives a happy medium between the arc at the points and the arc at the spark plug. A smaller condenser means more power from the coil but shorter point life due to pitting. A larger condenser will give you longer point life but sacrifice coil output.

Gene F · 08-13-2023, 06:45 PM

Well said Dave. And yes the bigger units on equipment (like a rooftop air conditioner) are called Capacitors. I used to be a HVAC mechanic, and we tested capacitors the same way. We'd also use the ohm meter to measure from terminals to the case to test for a shorted unit.

scicala · 08-13-2023, 06:56 PM

Thanks everyone for the information. It's very appreciated.

Sal

scicala · 08-14-2023, 12:02 PM

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Just an FYI for anyone interested. I had an extra 12V coil, and figured replacing that was easier than fooling with the condenser. Installed the coil and it started easier than ever and ran perfect, even under a heavy load.
Happy camper here.
Sal

55blacktie · 08-14-2023, 03:11 PM

Sal, fortunately you have a good coil. Finding a good condenser is easier said than done. There have been a lot of complaints regarding Chinese condensers, and coils, and fuel pumps.

scicala · 08-14-2023, 04:58 PM

Quote:

Originally Posted by 55blacktie

Sal, fortunately you have a good coil. Finding a good condenser is easier said than done. There have been a lot of complaints regarding Chinese condensers, and coils, and fuel pumps.

Yes, the Chinese junk is pretty frustrating. The Echlin coil I removed actually said made in the USA.
The coil I replaced it with was from a 60's Chevy V8 and said use with external resistor (which I did).

cadillac512 · 08-14-2023, 05:08 PM

Good deal,Sal. That old Delco coil might last forever.

Terry

Daves55Sedan · 08-14-2023, 07:57 PM

Yes good condensers are hard to come by. I have been using Echlin brand from NAPA. Put one in my '55 a couple years ago and still going strong. They are not made in USA though, I think they're made in Mexico. I ordered a couple of them from NAPA and carry the extra one in the car as a spare just in case.
Seems like if you could get a cast epoxy coil now, it would be better than the oil-filled ones. I had one in my '55 (yes it is still 6-volt) and it worked flawless for over 35 years.

scicala · 08-15-2023, 12:33 PM

Quote:

Originally Posted by Daves55Sedan

Yes good condensers are hard to come by. I have been using Echlin brand from NAPA. Put one in my '55 a couple years ago and still going strong. They are not made in USA though, I think they're made in Mexico. I ordered a couple of them from NAPA and carry the extra one in the car as a spare just in case.
Seems like if you could get a cast epoxy coil now, it would be better than the oil-filled ones. I had one in my '55 (yes it is still 6-volt) and it worked flawless for over 35 years.

The coil I installed did say oil filled on it. I read that you should mount it with the terminals in the 11 o'clock and 1 o'clock position, so that's how I mounted it.

Sal

Daves55Sedan · 08-15-2023, 09:44 PM

Sal, I would assume you'd want the terminals as far away from the biggest external heat source (the intake manifold) as possible. If that is correct, the 1-o'clock and 11-o'clock positions would be good (that is for a duplicate of original '56 Ford coil from the repro guys).
Replacement coils from the chain auto part stores have their terminals 180 degrees apart so the best mounting arrangement would be with terminals at 3-o'clock and 9-o'clock.
There is a small air gap in the oil-filled coils. Apparently it doesn't matter that much because on the 223 I-block 6 engines, the coil mounting bracket hangs off the side of the head with the coil mounted vertically (which keeps the terminals farthest away from heat but leaves them in a small air-gap.

08-13-2023, 05:15 PM	#1
scicala Senior Member Join Date: Jun 2010 Location: Detroit suburb, MI Posts: 3,712	Queation for the ignition experts Will the points arc to the point of doing damage to the contacts, if I disconnect the condenser wire to try and diagnose a bad condenser ? It would be run for maybe 5 minutes tops. The car is a '55 272 updated to 12 volts with a ballast resistor. Stock distributor. Thanks, Sal

08-13-2023, 05:35 PM	#2
cadillac512 Senior Member Join Date: Apr 2019 Location: Kansas Posts: 967	Re: Queation for the ignition experts It will be a bit hard on the points but won't destroy them. If they're in good condition a light dressing with fine emery cloth or a points file will make sure the faces are good. You probably won't even need to do that. Terry __________________ "It don't take but country smarts to solve the problem" (Smokey Yunick) '41 Merc Town Sedan / 260" 8CM engine '66 Fairlane four door / "warmed up" 302

08-13-2023, 06:32 PM	#3
Daves55Sedan Senior Member Join Date: May 2010 Location: Granite City, Illinois Posts: 3,008	Re: Queation for the ignition experts '55 Ford car ignition condenser, 6-cyl or V8 .21 - .25 microfarads; minimum leakage 10 megohms; maximum series resistance 1 ohm; for use with standard 6 volt ignition coil, 1.5 ohms resistance. HOW TO TEST A CONDENSER 1.) Remove the condenser from the engine (or at least disconnect the lead wire). Note the small metal connector located on the end of the condenser. This connector is the "hot" or power connection. The metal case of the condenser is the grounding point. Discharge the condenser by shorting the lead wire to the case. 2.) Switch the meter to the ohms position. Place the red lead into the "ohm" connector on the meter. Insert the black lead into the "com" or common connector on the meter. Set the resistance range to the highest available setting (if it is selectable). Connect the test leads together and zero the meter. If the meter won't zero replace the battery. (Yes, an ohm meter has a battery). 3.) Touch the red lead to the hot connector on the condenser. Place the black lead to the metal case on the condenser. The meter's needle should jump slightly to the right (toward 0-ohms), then should drop back to the left towards infinite resistance). Hold the leads in place for 15 to 20 seconds. This action places charge in the condenser. If the test shows any reading other than infinity, the condenser is leaking and needs to be replaced. 4.) Remove the leads and reverse the placement to the condenser. Move the red lead from the hot connector to the metal case and move the black lead from the metal case to the hot connector. At the moment where both leads are touching the correct points, the meter should jump towards the right. The second time the needle may move twice as far, as this action discharges the condenser. Holding the leads in contact should again result in movement of the needle back toward infinite resistance. 5.) Movement of the meter's needle indicates the condenser is good. If no movement was indicated on the meter in any circumstance, the condenser is bad and must be replaced. Retest the condenser several times for a consistent reading. In operation the condenser will "ring" at up to 300 volts, so the condenser needs to be rated much higher, no less than 600 volts DC. The ignition will likely work with any capacitance value between 0.05 and 0.6 microfarad. Too high or too low value may eventually transfer metal from one side of the contact points to the other side leaving a pit and a point. Capacity of spark coil capacitors ranges from 0.2 microfarad to 0.33 microfarad. Almost all automotive coils use a 0.25-0.29 microfarad capacitor. A capacitor may absorb moisture over a long period of time, and moisture can cause failure of the condenser. So it is possible that a condenser stored for 10 years or so might be bad or might fail prematurely in service. It is a good idea to check your traveling spare condenser occasionally. HOW IT WORKS Current flows through the points when they close. When they open the inductance of the ignition coil tries to maintain that current so an arc will be struck between them until the points open up enough to break the circuit. The more current you run through the points, the harder it is for them to break the current. That is why point systems have a condenser (called a capacitor in any other electrical system). The condenser slows down the reaction time of the coil to allow the points time to open and break the circuit. Without a condenser you will likely never break the primary current and get no spark from the secondary. Having a condenser that is too large will completely prevent arcing across the points but will also slow the coil so much that it is unable to strike an arc on the secondary. The trick is to find a condenser that gives a happy medium between the arc at the points and the arc at the spark plug. A smaller condenser means more power from the coil but shorter point life due to pitting. A larger condenser will give you longer point life but sacrifice coil output.

08-13-2023, 06:45 PM	#4
Gene F Senior Member Join Date: Mar 2012 Location: Ohio Posts: 2,010	Re: Queation for the ignition experts Well said Dave. And yes the bigger units on equipment (like a rooftop air conditioner) are called Capacitors. I used to be a HVAC mechanic, and we tested capacitors the same way. We'd also use the ohm meter to measure from terminals to the case to test for a shorted unit.

08-13-2023, 06:56 PM	#5
scicala Senior Member Join Date: Jun 2010 Location: Detroit suburb, MI Posts: 3,712	Re: Queation for the ignition experts Thanks everyone for the information. It's very appreciated. Sal

08-14-2023, 12:02 PM	#6
scicala Senior Member Join Date: Jun 2010 Location: Detroit suburb, MI Posts: 3,712	Re: Queation for the ignition experts Sponsored Links (Register now to hide all advertisements) Just an FYI for anyone interested. I had an extra 12V coil, and figured replacing that was easier than fooling with the condenser. Installed the coil and it started easier than ever and ran perfect, even under a heavy load. Happy camper here. Sal

08-14-2023, 03:11 PM	#7
55blacktie Senior Member Join Date: Aug 2020 Posts: 446	Re: Queation for the ignition experts Sal, fortunately you have a good coil. Finding a good condenser is easier said than done. There have been a lot of complaints regarding Chinese condensers, and coils, and fuel pumps.

08-14-2023, 05:08 PM	#9
cadillac512 Senior Member Join Date: Apr 2019 Location: Kansas Posts: 967	Re: Queation for the ignition experts Good deal,Sal. That old Delco coil might last forever. Terry __________________ "It don't take but country smarts to solve the problem" (Smokey Yunick) '41 Merc Town Sedan / 260" 8CM engine '66 Fairlane four door / "warmed up" 302

08-14-2023, 07:57 PM	#10
Daves55Sedan Senior Member Join Date: May 2010 Location: Granite City, Illinois Posts: 3,008	Re: Queation for the ignition experts Yes good condensers are hard to come by. I have been using Echlin brand from NAPA. Put one in my '55 a couple years ago and still going strong. They are not made in USA though, I think they're made in Mexico. I ordered a couple of them from NAPA and carry the extra one in the car as a spare just in case. Seems like if you could get a cast epoxy coil now, it would be better than the oil-filled ones. I had one in my '55 (yes it is still 6-volt) and it worked flawless for over 35 years.

08-15-2023, 09:44 PM	#12
Daves55Sedan Senior Member Join Date: May 2010 Location: Granite City, Illinois Posts: 3,008	Re: Queation for the ignition experts Sal, I would assume you'd want the terminals as far away from the biggest external heat source (the intake manifold) as possible. If that is correct, the 1-o'clock and 11-o'clock positions would be good (that is for a duplicate of original '56 Ford coil from the repro guys). Replacement coils from the chain auto part stores have their terminals 180 degrees apart so the best mounting arrangement would be with terminals at 3-o'clock and 9-o'clock. There is a small air gap in the oil-filled coils. Apparently it doesn't matter that much because on the 223 I-block 6 engines, the coil mounting bracket hangs off the side of the head with the coil mounted vertically (which keeps the terminals farthest away from heat but leaves them in a small air-gap.