mgbgt distributor damage

[reghog]

Does anybody have any ideas why the distributor centre electrode on my 72 mgb is wearing out prematurally.The current cap was changed about 3000 miles ago and though the car runs ok and starts well, after a little check over the other day I found the centre contact was worn to the point of no contact, buried inside its housing.And a dusting of carbon on the rotor arm. Also the plastic around the four outer contacts looks burnt or chipped. The previous cap suffered the same way after similar miles , though the centre electrode was actually snapped off. The cap and rotor are intermotor parts and I'm guessing there is something amiss ?!

[littleredrooster]

Two possibilities come to mind:
1. My grapevine tells me that some aftermarket 'classic' ignition bits are rubbish, in particular points, rotor arms and dizzy caps. Have you tried an original Lucas cap?
2. Are you using the correct coil - i.e. not one which should have a ballast resistor in circuit? A ballast coil without the resistor could quickly burn rotor arms, caps and brushes (and fail early).

[ShayneJ]

littleredrooster said:

Two possibilities come to mind:
1. My grapevine tells me that some aftermarket 'classic' ignition bits are rubbish, in particular points, rotor arms and dizzy caps. Have you tried an original Lucas cap?
2. Are you using the correct coil - i.e. not one which should have a ballast resistor in circuit? A ballast coil without the resistor could quickly burn rotor arms, caps and brushes (and fail early).

was just going to say just that ^ i have had the same issues with after market junk quality
rotors and caps on rover v8's

again ballast resistor correct coil voltage?

OR is your dizzy worn on some designs if the bearings are worn
the shaft can be forced up when driven so putting pressure on the center electrode and its surround
and rubs the hell out of it heating it up untill it fails.#
OR perhaps your condenser is failing which can also sometimes cause fried electrodes.

[PositronicRay]

Big vote for 123 ignition here, expensive but worth it.
For quality spares try the distributor doctor.

[Dog Star]

I can't add any more than what's been said already (especially the bit about quality of part) except just how pleased I am to see a post about a "proper" problem that can be fixed with knowledge, skill and ingenuity, and not "I've got an EML and am getting bottom raped for 10 minutes of diagnostic time".

It's most nostalgic

[reghog]

I was told intermotor bought out lucas so assumed the parts are quality ?. I will check the coil and condensor.
Thanks for the quick feedback and ideas.

Andy