Practically Classics Forum

Are they any better? other than having no rivit to hold it together and being a different colour is there any actual difference?

Apparently having no rivet to work loose is key to their difference.
If the ones you are on about are the genuine ones from martin the distributor doctor they are well worth using.
I fitted a nos black lucas one only to find its rivet was loose and it caused a misfire under load.

I think they are red as the carbon they put in to make them black could help with arcing problems if they over do it or so I was told. Also there were problems with the rivets being too long and doing the same - cannot for the life of me remember who told me this - probably the guy selling the red ones ! However I would go for them there have been some lousy black ones for a while

I don't think the red has any particular signifigance, because it would be just as easy to make a bad red one as it is to make a bad black one like the bad black ones that currently come in a lucas box.

Distributor doctor's red ones are good but they're no different to his black ones, because they're made like Lucas used to make them up to about 20 years ago. For a long time there were no good rotor arms available and I was using old discarded spare ones salvaged from my shed because they were better than new ones- my Vitesse ran for ages with a modified genuine 70's Marina arm and the timing altered to suit because it was the last decent rotor arm I had

Distributor doctors ones don't have the rivet, just like proper old Lucas ones, and they don't break either like the new Lucas ones do.

Pilkie wrote: I fitted a nos black lucas one only to find its rivet was loose and it caused a misfire under load.

This is the problem I have although after bunging a halfords cheapo rotor arm on the problem went away. The metal on it is about 2.5x thicker than the "lucas" arm.
I saw them advertised in PC but google reveals LOTS of different suppliers for them. I'll give the distributor doctor a ring and see if they do them for a rover v8.
Cheers

the only thing I can add is that I spent a lot of money with garages trying to resolve a missfire problem and as soon as i fitted the red rota arm all issues were sorted

Regards john

The red ones sold on eBay by simonbbc are excellent.

A bit of tinfoil and a bottle cap has to be better than the Lucas Black rubbish. If I'm forced to use them, I'll keep 2 spares in the Landrover.
That was bourne out of the ignition dying on the M6 passing the ramp where chorley services empties onto the inside Lane. Having to coast across that to the hard shoulder during rush hour wasn't pleasant, and I'd like to share that with the Lousy Brummie Beancounter who thought that they were being smart.
(The Dizzy arm literally fell apart) - others have just gone into dead short mode with the same effect
I'll even give them a lift.

Attached to the Drop Hitch

I think Stagman has a good point, carbon black is a good conductor and will easily short out if there is too much in the resin mix.
Phenolic resin is intrinsically red in colour so it would seem that the red rotors have a higher resin content and probably use iron oxide as a filler so would be more resistant to charring.as well as being stronger.