OHC Rotor Arm Warning

[Simon]

Have you checked your rotor arm recently? I had a MOT booked for the Cammy Jensen today so when I went to check the car out yesterday it would not start!! first time after 530 miles on the summer rally. Checked fuel and fuel pump-OK. Removed distributor cap and opened the points - good spark. Sprayed with brake cleaner to remove oil etc. Removed rotor arm and the steel springy contact to the coil lead parted company with the rotor arm adjacent to the rivet which holds it in place. Panic stations - I do not have or can't find a spare - What do I do? I cleaned up the steel springy bit and the brass bit on the rotor arm with emery paper and soldered it back in place and it works but for how long? Car got to MOT station and passed. Spares already ordered from Yesterday's Components (Harry Edwards) - Remax No ES31 - £5 plus postage. This only applies to D41 and DS4 distributors.

See you at the Hatchgate on Sunday 12th October.

[Simon]

WARNING

Before using replacement rotor arms CHECK that they will rotate fully in a spare distibutor or if you have not got a spare remove the distibutor from the car. On mine the brass piece of the arm fouled the four contacts inside the distributor cap and lifted from the shaft of the distibutor and the drive lost and the car stopped less than a mile from home on the way to the autumn meet at the Hatchgate so put the old soldered up one back in. The rotor arm therefore needs to be ground or filed down to provide clearance, this is because the rotor arm was originally intended for another vehicle. An Austin Seven parts supplier I spoke to told me that they check and grind every one of this type of rotor arm before dispatching them to avoid customers complaining.

[Ian Grace]

Rotor arms for the DS4 and D41 distributors are identical to Vauxhall rotor arms of the seventies which are still in relatively plentiful supply. The only difference is the length of the brass contact arm which has to be trimmed and filed about 1/4". If you don't take enough off, then you end up with Simon's problem!

Also, the Renault Dauphine distributor cap from the sixties is identical to the DS4/D41 cap, and these sometimes come up at autojumbles and on eBay at a good price.

As for DS4 condensers, these are virtually impossible to source nowadays. I did find one for the Semi-sports, and it lasted about 100 yards before the ancient insulation broke down! I have fitted modern (12V) condensers to Minors and they work perfectly, but don't look particularly pretty when hanging off the distributor by a wire.

Does anyone know of a modern alternative for the DJ4 rotor arm?

[Ken Martin]

I have fitted a modern condenser inside the case of an original one...
Ken

[ian judd]

If anyone needs a distributor for general running around rather than for show, I can certainly recommend the PAL type as fitted to Skodas 120,130,and Rapid. They have the advantage of auto advance, and are very well made. Spares are cheap and easy to get. The only alteration required is a thick washer above the clamp as they are a little longer, and filing down the diameter of the head of the clamping bolt which fits in the block. My engine runs much more smoothly than when I had a Lucas DK4 installed. There are brand new ones on ebay for £45. A lot of people like the Bosch one but they are more expensive and require some machining as they are a little too short in the barrel part.

Ian

[Toby]

I believe Trevor has found an alternative unit too. Has anyone found the points heel on modern pattern sets wears v.quickly? It appeared that part of my poor running on the way home from the rallly was due to a tiny points gap that was fine before clocking up the 500 or so miles.

[Simon]

Ian, DJ4 rotor arms are available from Austin 7 suppliers. Why do you want one?

[Ian Grace]

Hi Simon,

I wasn't thinking about obtaining one - just curious. However, thinking about it, I wil need one for the McEvoy at some point!