Ive had some bother with pinking on my car, I thought I'd have a look at the dizzy

I have a DK4 dizzy on my seven, it seems to be advancing itself ok, but does not retard back.

When I turn the rotor arm it moves free enough, but doesnt return.

I took off the top to find that when the arm is fully retarded the springs holding the bob weights seem to be loose.

Perhaps my springs are tired, or that it is assembled wrongly. Has anyone photos of a correctly assembled bob weight assembly, or know of a supplier for new springs?

Many thanks in advance

Hedd

Chuck it under the bench and put a new Bosch type on instead, I did and its the best thing I have ever done.

I went down the route of trying new springs etc, but your whole dizzy is probably well worn out.

Phil

No way, thats a cheats soloution.

My Austin is run on a shoestring, I have a steam roller that I'm restoring to spend my money on.

I have 101 better things to spend the money on that machine, definatly not for the want of a couple of new springs in the Austins dizzy.

I take your point Hedd but having bought the Bosch alternative from Willie Mackenzie at Beaulieu I can report that I reckon it is worth 5 -10 mph on top speed on both my Ruby (low comp head) and Special (high comp Dante head). Acceleration is marginally improved. Not cheap at about £80 with a black cap (normally comes with ghastly orange one) but possibly worthwhile if your original dizzy needs a full makeover... Nick

Hedd,
There's some information and photos on springs and advance curves on the Speedex site under the Special Builders Guide page.

http://speedexa7.users.btopenworld.com/index_files/Page1752.htm

Check that the springs are fitted into the right holes in the little square plate.

Dave

Based on the pic on that page, the springs were in the correct hole. I guessed they were as I tried them in the other hole last night and the whole lot siezed up solid.

Next question is where can I source new springs?

Hedd,

You may be lucky enough to get some good old springs if you contact the usual spares suppliers, alterntively there are a number of generic spring suppliers on the internet. The problem is measuring the spring stiffness accurately, although you may find that you can measure the wire gauge, od and number of turns to get close enough.

Regarding the comments on the speedex website about testing the advance vs rpm curve using a variable speed motor and strobe light, my dad did it a few years ago with a sewing machine motor and control pedal.
He was rebuilding a DK and found that he had a couple of different stiffness springs amoung his spares and wanted to see what they all did. I think there were two different stiffnesses of springs in the DKs that came off a7s, i think dad went for the rotor plate with the most advance (8deg) and one soft and one hard spring although that may not have been an original combination. He made the assesment based on the amount the way he has to advance the DJ in his box saloon.

I have experience mapping a modern motorsport ECU including setting the advance curve and i would definately recommend going through the process of running an engine on a dyno with a DJ then fiddling a DK to get the right advance curve.

I will be testing the engine for my ulster rep on a dyno before it goes in the car and will aim to make notes on advance vs rpm so i know where to set the adv lever, will run the car with a DJ.

Regards

Rob

HEDD:

Whilst you might save money in the short term trying to renovate your DK distributor, it probably won't save you anything in the long term as it is likely the whole thing will need a rebuild. For general use, the Bosch is by far the easiest way to go and at least the time saved is time you can spend on your roller.

Many of the competition men have gone back to the good old DJ distributor however. Little to go wrong, reliable, simple and, once it's set, it's set.

STEVE

If you can find someone with a Series 2 Morris minor or Austin A30 Distributor (the early type DM or D2 I think, not later Model 25D) which has reasonable springs, they will do the job. Mightn't be exact but will get you out of trouble.

Real problem is though, if your springs are flogged, the weights and action plate are also probably in the same boat. Don't try and use the action plate and/or weights from the distributors mentioned above. They are designed to operate with the opposite rotation.


The alternative is to take the springs to your local springmaker who should be able to wind you up a pair, but that will probably cost about ten quid. Essential that the new springs closely follow the existing springs in terms of diameter of wire, number of coils and finished diameter of coil, and that the inside distance between the tow attaching loops, at reat are the same as existing, less the "stretch" which has no doubt occurred.

Yes, all the above is a bodge.

The DK4A's can be rebuilt to work perfectly, but that would cost more than the price of a brand new Bosch unit, a lot more if the action plate and shaft need to be replaced/built up to eradicate wear.

Regards

Barry R.

Regards,

Barry R.

I have had a long and frank discussion about my dizzy with the 'Distributor Doctor', (do a google search). We have discussed the wear on my dizzy. From what I can make out, other than the springs my dizzy didnt sound to bad to him. The plate is pretty unworn and there seems to be bugger all wear in the weights. Apparently the brass bushes in them are usually knackered

However that said, supplying me new springs was a guess, he has various spec springs in stock, but when he overhauls the dizzy he makes a guess then tests the advance curve. He could send mre some springs and I could fit them, but he described it a bit like ******* in the wind in terms of getting the correct advance curve.

Also cost of a rebuilt DK4A is about 30quid more than a new Bosch .

In view of my pinking problem, I have been advised to doctor my current springs so that they work (i.e spring back the rotor arm) and run the car to see if pinking persists. If it does not then I need a new/better/rebuilt dizzy. Basically this will probably mean I'll fit the original dizzy with the dangly condensor and the control rod . nice and original that way

At the risk of a toe treading session, I agree with Hedd on this one, especially about the originality. On the basis of reductio ad adsurdum, why just fit a modern distributor? Why not fit a Ford Focus engine or even, just get a Ford Focus!

Hedd

I tend to be known for not spending money , and sometimes using unorthodox aproaches to fiddle with things. Because of this I havnt fitted a Bosch as they are expensive and way to orthodox for my liking!! . I am certain that they are probably the best solution to the problem but thats not what some of us are after!
Why not just lock up the one you have like I have and decide for your self the advance at anytime you feel like it? I will no doubt be shot down in flames but in my defence my own special drives so much better now I have ditched the worn out advance (same trouble as you are having) and fitted a manual control. Of course its not just a standard manual control as Austin designed its a Heath Robinson collection of parts that just about hang together and work, albeit in the opposite direction to the standard cars! Why not become more involved in the driving with some extra controls, I'm sure the steam roller requires 3 hands to drive so why not the car as well .

Steve

During a run out in the RP yesterday, the old girl developed a slight misfire when pulling hard. I thought at first it was just the heat (it was 32°C down here yesterday)but I thought I'd better investigate anyway.

My RP has got a Bosch dizzy, so straight away I thought that perhaps the plugs needed a clean, or there was some muck in the carby. Anyway, on opening the bonnet, just by chance I had a waggle at the distributor cap and discovered that the body was loose - the retaining bolt had untightened itself, thereby reducing the earthing quality. A quick tweak with a spanner and all is back to normal.

I wonder if the many problems we hear about rough running are all related to the poor earthing of a manual advance distributor?

Dear Mr . Reckless, please explain the term untighten?

.

Re-loosen perhaps?

I thought the terminology was quite clear. Similarly, when I say I'm leaving the room for an undrink, no-one has queried what I mean. Cheers, Bill in Oz

Hedd

It seems that there is divided opinion on this one, I too am an EX traction engine owner and can understand your concerns about where to spend the money, traction engins are a money pit nowadays and it seems that only business men can afford to own, run, transport and maintain them.

If you send me your postal address by PM, I will dig out some of the new Lucas distributor springs I have hoarded, and you are welcome to try them out on your original dizzy, as long as nothing else is knackered you might get lucky.

Phil

I 'av been 'avving some problems vith remembering words in Eenglish zees days. Per'aps eet eez ze Pastis wot I 'ave been drinking. 'Owevver, eet does 'elp with ze wayward steering of ze Austeen, (or at least a good excuse)

Phil, many thanks for your kind offer, however I have given in and bought a german Dizzy as reccomended.

With all the indications that my car will 'gain 10mph', I look forward to cruising at 60mph!. The car always went like sh1t off a shovell anyway!

Hedd

Glad to hear you are sorted out. I would be wary about cuising at 60 if you are on cable brakes and standard steering, things can get very busy at that speed.
Just as an aside, in my experience once you get sh1t on a shovel, it takes absolutely ages to get it all off again.
Are you saying your car was always very slow ??

Phil

I believe the shovel needs to be shiny to get the required effect .

Steve

Ha ha, cable brakes are fine if you look after them. You just need to press the pedal hard!