Condenser Longevity?

[Jessie The Jeep]

How long on average do your ignition condensers last. I've had some that seem to go on for ages, while the life of others can be compared to rare sub-atomic particals! I put a new one on the Dodge at the beginning of February, and have just had to change it today after only 752 miles.

 

I'm no expert on these little silver sausages, but seven months and 750 miles seems a bit pants!

 

What's been your experience of their life expectancy?

[Willyslancs]

years ago, our dodge use to eat them too.........

[Jessie The Jeep]

Does the vehicle operating voltage make a difference to condenser age. My Dodge is 6v, but obviously what goes through the points is somewhat higher!

[Tony B]

My 12 volt has never been througfh a condenser, so voltage might be in it. For every Watt 6 volt requires twice amapage of 12.

[woa2]

I have had problems with original Ford V8 condensers failing and now only use modern Lucas ones (DCB121C). Clive Elliott is the Expert on Condensers, have you contacted him yet?

[Jessie The Jeep]

The ones I've been using and the spares bought are from Jeeparts. They don't look like old stock, and the last lot had the ends of the box ripped off so there was no indication of part number or manufacturer to give a clue as to where they come from.

[ted angus]

How long on average do your ignition condensers last. I've had some that seem to go on for ages, while the life of others can be compared to rare sub-atomic particals! I put a new one on the Dodge at the beginning of February, and have just had to change it today after only 752 miles.

 

I'm no expert on these little silver sausages, but seven months and 750 miles seems a bit pants!

 

What's been your experience of their life expectancy?

 

Thinking back to my shop floor days in the RAF, On Ford industrial engines, plugs, points & condenser were all changed at the same time, either annually or every 10k miles or on static kit about 350 hours running, not changing the condenser leads to reduced points life. condensers hate damp so your's may have been stored in the damp ??

TED

[Jessie The Jeep]

Before it was fitted to the truck, it was in an air tight plastic container in one of the truck locker boxes. The one just fitted was stored in the same way, so lets see how that lasts!

[Willyslancs]

funny , ours was 6v too.......

[fv1609]

It is immaterial whether it's 6, 12 or 24v. Condenser is usually rated at 500v to absorb the back EMF as the points open & magnetic field collapses. It matters not what voltage the primary winding is designed to work off. The spark at the points is this back EMF. If they fail so rapidly are you certain that they are proper distributor condensers? BTW am at GDSF, 3G clogged up in day. Took 1.25 hours to respond to a PM earlier!

[fv1609]

PS It's not so much usage it has had but the age since manufactured. Even its NOS, looks new & was still wrapped up, the paper thin dielectric will break down with time despite having never been used, I,m afraid.

[listerdiesel]

Much as Clive says, older capacitors with paper dialectric are prone to failure through moisture getting inside the casing through ageing end cap seals.

 

Modern polypropylene dialectrics and so on seem to be pretty reliable, it seems to be moisture ingress that starts the problems.

 

I'm going to be testing some NOS Fairbanks-Morse capacitors on a Megger today, to see how they fare on insulation. I'll be using a 1000V Megger unless I can find the smaller 500V one.

 

Peter

[Jessie The Jeep]

I suspect they are new for the reasons mentioned before about box id being removed. The latest selection have arrived in ziplock bags. They have all come from Jeeparts over the last year. Not sure what WW2 condensers had, but the wire out of them looks to be a modern plastic insulation ( see attached ).

 

 

[andym]

Are the 6V condensers physically a different part to the 12V ones? They form a tuned L/C circuit in conjunction with the coil and as a 6V coil would have a different step-up ratio to a 12V one I suspect it also has a different value of inductance, requiring a different condenser to retain the correct L/C value.

 

Andy

[Jessie The Jeep]

I've been told by a number of sources that condensers are a common component no matter what the input voltage is!

[ted angus]

I've been told by a number of sources that condensers are a common component no matter what the input voltage is!

 

Steve, Andy is on the right track, its not just wether the engine is 6, 12 or 24 volts; The condensor or capacitor as it is sometimes called is more matched to the coil with regards to the coil's primary windings than the volts the engine is getting initially from the battery; remember the primary may be between 230 & 600 volts whereas the secondery at discharge can give tens of thousands. Its all down to the original design of that particular ignition circuit. . Condensors appear to range between 0.08mfds and 0.8 mfds. As long as it physically fits most condensors will work, but to get design performance and reliability, it should be the one originally called for at manufacture or a modern equivalent.

[ruxy]

By the 1980's most ignition automotive capacitors (of quality) were in fact of metalllised paper such that they were "self healing" apparently in the event of electrical breakdown between layers - then the heat developed vaporized the metal and cleared the fault - magic !

Then the electronic ignition types came along , mass production will have ceased in the UK & EU probably , even out of a Intermotor , CI or even Lucas box - they will may be made in China out of primitive dielectric construction ?

Edited September 1, 2011 by ruxy
spelin

[slick50]

It is immaterial whether it's 6, 12 or 24v. Condenser is usually rated at 500v to absorb the back EMF as the points open & magnetic field collapses. It matters not what voltage the primary winding is designed to work off. The spark at the points is this back EMF. If they fail so rapidly are you certain that they are proper distributor condensers? BTW am at GDSF, 3G clogged up in day. Took 1.25 hours to respond to a PM earlier!

Hi Clive...should I fit any specific condenser on my Hotchkiss 24 volt please....can't seem to get her running right.Many thanks.

[fv1609]

I'm not familiar with the electrics of a Hotchkiss.

 

But most distributor capacitors are in the region of 0.2mfd. So I would suggest any capacitor that fits in the space that is designed for a distributor & is new should do fine.

 

If you want me to test any then send them to me with a SAE.