electronic distributors - any further feedback?

[Ruairidh Dunford]

Tony,

the unit I have fitted to the Pearl is nearing that mileage - I think 20’000 was the litmus test suggested previously however, so I will keep going...

[Tony Press]

Tony,

the unit I have fitted to the Pearl is nearing that mileage - I think 20’000 was the litmus test suggested previously however, so I will keep going...

Ruairidh,

Do you lubricate the spindle regularly and how ?

Are your bushes steel or brass/bronze ?

[Ruairidh Dunford]

I lubricate all distributors weekly, if they are being used - daily on long tours.

I have no idea what the bush is made from but I will investigate, if it fails.

In 1992 I was lucky enough to be given a brand new DK4a (it was left in the seat of the RN, by a stranger, whilst parked outside a school I was teaching in) I fitted it and used it - was lovely. After 30k it needed a new bush and some repairs to the bob weights. Such things are (beyond?) rare these days but the newly available unit is cheap, easily replaced and will probably outlive the mileage most will put it through.

Most importantly, nobody is being forced to use them but, of those that do, most enjoy the improvements they offer.

[Ruairidh Dunford]

I lubricate via the side oiler and a squirt of oil through the gap in the base plate under the cam beneath the rotor arm - anything else I should do?

[Tony Press]

I lubricate via the side oiler and a squirt of oil through the gap in the base plate under the cam beneath the rotor arm - anything else I should do?

Not that I am aware of ! You are much more thorough than I am with DK4's and a Bosch replacement !

I suspect your thoroughness  explains why your cars run so well.

[Ian Williams]

Ruairidh what would make a useful comparison for those who are wondering about long term robustness is if you were to strip and measure a high mileage Accuspark as throughly as I have with a new unit. My belief was that the lack of wear in a new unit was the chief cause of the improvements many were reporting, however my investigations have proven beyond doubt that the new Accuspark distributor in my possession was, through cheapness of build and probably a lack of quality control, actually exhibiting as much if not more play than a worn Lucas unit. The only think working better in the Accuspark was the advance mechanism, which provides a large part of the answer, however the Accuspark advance curve is not particularly good for many sevens and this is why in my opinion timing difficulties are often experienced with them. I suggest many, as Martin has, will find that the electronic base plate will work as well or better on a Lucas distributor, that is unless it is absolute scrap! I will post further measured results from all the road tests I have done, they take a while to compile, and I am trying not to be subjective so bear with me.
I am doing all of this because many have been lead to believe, unintentionally or not, that they have to make all sorts of modifications to a seven (no not just electronic distributors ) whereas I maintain, and will continue to play devils advocate, that if one puts things into good working condition an awful lot of these mods for normal everyday use are completely unnecessary. And all this is coming from an avid special builder! Horses for courses and we all have different reasons for playing with sevens, however with some of the nonsense talked at times it is a minefield for inexperienced.

[Ruairidh Dunford]

Thank you Tony, I am sure the same can be said for most.

I am afraid those wishing to inspect one after extended use will need to put the work into driving their own 5000 miles and do the check themselves.  As already stated I will strip the unit I have, if it fails.  I am absolutely not taking apart a perfectly functioning item.

The play has been discussed (and filmed for all to see) in the past.  Unlike the traditional units play does not affect the functionality of the unit by virtue of the way it functions.  In short, if your new unit displays play do not be concerned as, in my experience, it makes no difference to performance.

If an individual likes the unit they should use it, if they don’t, they should not.  

Be happy in your own choice, it is the only one you can truly control.

[Bob Culver]

Further to Peter Burtons comments on page 6 I tried auto distributor on my RP years ago, for some reason without manual override, but soon reverted to manual as was never sure if it optimum retard whilst maintaining power. It is difficult to separate performance from noise. In a very hilly city and in stop go traffic  the manual often enabled a brief difficult change into 1st to be avoided by retarding the spark. Of course, as with most, the springs fitted and exact advance characteristics were anyones guess.

I occasionally  get enquiries about optimum advance for Javelin cars and Bradfords. For the keen I suggest arranging a temporary manual override. The throttle controls from lawnmowers, some choke controls etc can be quite simply arranged.

I am always mystified by the claims of smoother operation with new substitute distributors. There is spark scatter with an old worn unit, but a good one is essentially same as millions of other Brit cars. Apart from making the engine sound rough I dunno if scatter makes much difference to power.
The spark occupies very many crank degrees; possibly with a modest system ignition is not always immediate, even with a normal strength mixture. Like pregnancy there is either ignition or not. But cars with poor plugs, insulation etc often run at low power without actually missing. I suspect ignition occurs late in the spark period. I found on my car closing the plug gaps made the engine more smooth, like retarding spark, so the form of the spark makes a difference.

[Colin Reed]

Hi,
If any one needs to test a distributor there is only one way and that is on a Test Bench where all tests are repeatable 
To get a comparison between two distributors ,
That is why just driving down the road will not work to open to interpretation .
Years ago while working on a mates Hydraplane  we had a miss at high revs and the quickest way was to put it on a test bench and the result point bounce at 9000 rpm that's Engine revs.

Colin
NZ

[Ian Williams]

Colin, a bench test comparison will not tell you how one distributor will perform against another on a car, however do I agree it is useful for diagnostics if you have a known set of parameters to compare against.