Classic cars forum & vehicle restoration.

Ashley · Joined: 02 Jan 2008 Posts: 1426 Location: Near Stroud, Glos

Over the last few years I have had numerous coil failures, I've been driving since 1963 and never lost one until recently and it's driving me nuts.

They've all been Lucas, some have leaked oil and overheated, some turned out to be ballast resistor type with the wrong part number, so overheated and failed and the last one wouldn't pull from low revs and misfired when it was hot. I'd fitted it as a precaution in case the old Lucas on the car was dodgy. I put it back on and I now have more power and more revs as well as a smoother engine.

I can't believe it, but it's true and may affect any of you if you buy Lucas, or the later ones might be fine. I Don't know, but for now I'm buying coils off PowerSpark on EBay. They seem good, they are cheap and they are black which is good in old cars. If these give trouble, I'm told Bosch VW Beetle coils are the best ones because the quality is very good and they are pressure filled with oil so can be used upside down and will still cool properly.

For the record, old cars need slow fat sparks. The original coils were 4.5 Ohms and produced about 13,500 Volts. The basic, general purpose, modern coils are 3 Ohms and produce 30,000 Volts and are the best choice. Sports coils produce 45,000 Volts and often cause rotor arm or distributor cap failure as well as not producing the right type of spark unless someone is revving his Hilman Minx to 15,000rpm.

All the above refers to 12 Volt coils, but if you find a general purpose coil for LPG or agricultural use, grab it. It is best for old engines.

Ash

peter scott · Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh

I hate to see modern components in old technology and that includes ignition coils in cars.

I've used an original Lucas coil (similar to photo) for the last 20 years in my car and never had any problem with it. I did suspect it of trouble when I got a misfire due to a totally different failure:

http://www.jaguardriverforums.co.uk/showthread.php?t=357

..but I think there is more reason to suspect modern parts of premature failures than original equipment.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

peppiB · Posted: Sat Nov 02, 2013 5:25 pm Post subject:

I have had 3 faulty new Lucas coils supplied in the past year. One of them had the oddity of working when it was perpendicular but not when it was fitted to the car horizontally.

I have noticed that these do get somewhat hotter than the old ones that used to be fitted

Ashley · Joined: 02 Jan 2008 Posts: 1426 Location: Near Stroud, Glos

I'm glad I'm not alone.

I recognise that old Lucas coil Peter, my MKVI Bentley had two the same, sadly both have expired thanks to them being on the bulkhead above the exhaust system/manifold.

ukdave2002 · Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire

Alas I fear that much of the Lucas low volume stuff that classics need, is made to a cost, rotor arms, condensers, coils all seem to fail far more frequently, than in past years Sad

The voltage that a coil produces is not fixed by the coil type, although every coil will have a maximum voltage that it can develop; the actual voltage is determined by a combination of; the plug gap, compression and conductivity of the fuel air mix. When the points open the voltage in the secondary rises until the plug fires or finds another easier path to earth.

On something like a pre war Morris, the plugs fire at about 8Kv, if you fit a 45Kv "flame thrower" coil, they will still fire at 8Kv!

Dave

peter scott · Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh

Keith D · Posted: Sun Nov 03, 2013 2:54 am Post subject:

In 2006/7 I found it impossible to buy new 6v coils (in the traditional shape) in Australia for my Chrysler and Austin Seven. I phoned Vintage Supplies in Norfolk, UK and they sent me a pair. These were unbranded, so probably came from Taiwan or similar. Both cars start very easily, idle beautifully and pull well. And importantly, look just like the ones that were originally fitted. I'm one very happy little motorist!

Keith

vitesse · Joined: 03 Jun 2013 Posts: 561

Interesting thread. I have just bought a Bosch Blue High Energy coil as mentioned by Ashley.

They do come highly recommended and they aren't too intrusive on their labelling and can be quite easily rotated if you don't want to see any of it.

I bought it from a supplier on Ebay or Amazon can't remember which and it was only about £22.00 which half the price I have seen other people selling it for.

Roger-hatchy · Joined: 07 Dec 2007 Posts: 2135 Location: Tiptree, Essex

I have just had 'ANOTHER' problem with lucas coils, fifth one to give problems since 2009,
This time it's the terminal post, CB side had broken off.

Had the head off, blown gasket.

About an hour ago after everything was back together on trying to slide the spade terminal back on to the coil I thought the lucar terminal on the coil was loose, NOT SO

It is the post, it has broken, it's a hollow tube with a wire in the middle soldered at the top, doubt it is thicker that a piece of paper.

More chinese crap.

emmerson · Joined: 30 Sep 2008 Posts: 1268 Location: South East Wales

None of my Range Rovers has run well on Lucas coils. I've replaced them with Bosch, and solved all my ignition problems.
As my cars run on LPG, they need to have a very healthy spark, and Lucas sadly is no longer up to the job.
In my book, "coil" is now spelt "Bosch".

kevin2306 · Posted: Sun Nov 24, 2013 6:02 pm Post subject:

any specific bosch coil for 1960's cars? id be interested in changing mine too but a bit bothered about ending up with a cheap Chinese copy

kev

rjt10/4 · Joined: 26 Nov 2012 Posts: 214 Location: Minions Cornwall

• The Lucas motto: "Get home before dark."
• Lucas is the patent holder for the short circuit.
• Lucas - Inventor of the first intermittent wiper.
• Lucas - Inventor of the self-dimming headlamp.
• The three positions Lucas switch - Dim, Flicker and Off.
• The Original Anti-Theft Device - Lucas Electrics.
• Lucas is an acronym for Loose Unsoldered Connections and Splices
• Lucas systems actually use AC current; it just has a random frequency.
• "I have had a Lucas pacemaker for years and have never had any trou..."
• If Lucas made guns, wars would not start.
• A friend of mine told everybody he never had any electric problems with his Lucas equipment. Today he lives in the countryside, in a large manor with lots of friendly servants around him an an occasional ice cold shower...
• Back in the 70's, Lucas decided to diversify its product line and began manufacturing vacuum cleaners. It was the only product they offered which did not suck.
• Q: Why do the British drink warm beer? A: Because Lucas makes their refrigerators
• Alexander Graham Bell invented the Telephone. Thomas Edison invented the Light Bulb. Joseph Lucas invented the Short Circuit.
• Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars, kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."