Rotor arm warning

[chrisfell]

A little over ten years ago my E-Type rolled to a dead stop on the north bound M5 near Bristol. Being a sunday there was no chance of replacing the component that had failed - the now famously fragile non-OEM rotor arm - so it was flat bedded home, the only time this has happened during my stewardship. Fearing a repeat I've carried replacements ever since, despite no longer having a Lucas dizzie on my car. You never know who else might find themselves stranded with an identical failure.

I had thought that after more than a decade the stock of dicky rotor arms had been drained from the parts supply system, until I watched a one off special of Phil Glenister and Ant Anstead's car restoration program. This featured a very early Lotus Elite - the actual car used by Lotus as a display car in 1958. Having been rebuilt it was being race tested at Silverstone this summer, when it died - rotor arm failure. It seems we are not out of the woods yet!

The car was sold at auction at the NEC Classic Car Show this month for £108k (bid price).

[Heuer]

The only rotor arms worth installing are the red ones from Distributor Doctor:

"Recently manufactured rotor arms have been failing because the typical "mix" used in the injection moulding nowadays contains more carbon blacking and is therefore more conductive. Still more importantly, the rivet which holds the brass inlay into the moulding is slightly longer than the original, bringing it too close to the spring clip on the underside. The high tension current, averaging 30,000 volts, is always looking for the easiest route to earth and shorts out from the tip of the overlength rivet, through the reduced thickness of more conductive plastic and the spring clip on the underside of the rotor arm, to earth out down the distributor shaft. Result - no sparks at the plugs. The situation sometimes rectifies itself on cooling, but then reoccurs with increasing frequency until the rotor permanently short circuits."

http://www.distributordoctor.com/red-rotor-arms.html

[cactusman]

Use a red one from the distributor doc...problem sorted.....although I carry s spare anyway

[richard btype]

I have just received back the dizzy from the Doctor - looks amazing, but asked him to provide an appraisal of the condition of the unit before he started his overhaul.

He gave me a report and commented that the points and contacts were cheap and nasty - (worn bearing etc) those items were not that old and so asked how one were to be sure of purchasing quality items - "I supply them"

Cannot wait to get the dizzy refitted and tune the engine - first I need a new crankshaft damper!

[mgcjag]

Watched that program last night and when Ant said the car was let down by a £2 part and showed the black rotor i thought you shoukd have piad £5 and got a red one

[chrisfell]

"Ant said the car was let down by a £2 part and showed the black rotor i thought you shoukd have piad £5 and got a red one"

'speaks quietly' It was a blue one, not black.

[richard btype]

I very much enjoy the programme the way it is put together, simple humour, some research and insight. It travels along at a good pace and they clearly do a good job for many of their projects have sold at top market prices.

But saving on a cheap rotor arm - dear oh dear!!!