This is an excellent question, and one that I am very keen to see answered. The reason being, no bugger will ever do it. It's very common to hear "dizzy type X has the wrong curve for engine build Y" but it's never followed up with WHY. This curve business gets spoken about it hushed tones like some kinda black magic. Hell all it is, is X advance at Y revs, X+Z advance at Y+V revs (I should have started earlier in the alphabet), out to max advance at Q revs. If people know enough to know that it's wrong, they should be able to say what it should be.
Either that, or they're just parroting what they've heard elsewhere but never thought to ask this question.

I'll go out on a limb here and say they most people who know enough to care about the timing curve are worried about it for power, not economy, and in a power situation you're usually at max advance already anyway, so what's the big deal.....time the car to max advance and be done with it.

If you're worried about every last .5 kW you're not going to be buying a 2nd hand off-model dizzy, so all this is irrelevant. If you're truely worried about economy, don't drive a mini, go buy a diesel MKV Golf.

/rant

I will put up the curves and show what wrong with them when I have time to set them out properly and clearly.

I am not concerned with getting every last 0.5 kW from the engine from ignition timing, however I would prefer to avoid severe engine damage from the incorrect ignition timing / advance curve. All too easily Wrecked.

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The simple reason to sort out the correct curve is so the engine runs at its best

I have changed my curve and dizzy couple of times each time with good improvements

The changes have produced better starting, better idling, smoother power you get the drift.

My engine is a mongrel made up of parts I have collected over the last two decades.

The short block was machined and modified by Lynn Rogers and assembled by me with a professional engine builder giving me one on one instructions.

The head was ported and polished to Vizard Specs by a profesional head porter who worked in the UK many many years ago all the chambers have been CC to make sure they are the same. The springs have been individually been checked for height and poundage on the seat again this head was done 20 years ago

The cam is a RE13 direct from Graham Russell in OZ (I used to live in OZ) ground on a brand new standard cam (had it for 20 years)

Compresion ratio is 10.35:1 with all the psitons stitting at the same level

Rockers are Toyo built by me to ensure that the lift is equal to get maxium lift at the best geometry

Dizzy is a A+ metro one which I modified to fit an A series engine has been set up to match this engine which is a week end warrior set up but you could drive as daily driver if you wanted. The curve was set up bt GR to match the specs of his cam and my other bits and pieces.

Bacically I tried to build an engine out off all the parts I have collected at a budget using all the research and knowledge I have gained in the last 25+ years of playing with Mini's and plus the help of some very clever peope..

No off the self dizzy was gonna work for me as I had changed to many variables.

So often two many people just buy off the self part through them together and expect it to all work. They do but how well,

Drive a Mini with a engine that has been well built and well planned out regarding the combination of parts and you can feel the difference

There is a hell off a lot of work and knowedge required to build a good engine that drives well and it really dosn't matter if its putting out 50 or 150 bhp its how it runs that counts

So if someone is trying to sell you a dizzy and dosn;t ask you the specs of your engine, keep your money in your wallet.

If I want to go any faster I will buy a Motorbike

Grizzle over

Kiwiinwgtn

I did a rough setup of a "123Tune" on a volvo which gives you programmability but it was a pain!

http://www.123ignition.nl/id/50.html

Cool, keen to see this. The 123 crowd seem to be one of the few (if not only?) to publish their curves, so I'm keen to match these against the 'perfect' mini ones and see how much difference there is.
123's selling point is ease of use, reliability, and multiple applications. This last point is missing for most other aftermarket dizzy's so they seem to try and use the "our curve is super-mini-blackmagic-mojo" as the selling point, which quite frankly I just find annoying. It's science, yes, but it's pistons and flame front not thrust, so it's not rocket science

Kiwiinwellywood, do you have the details of what yours is?

I cant actually find the spec sheet which anoys me some what

But basically GR reduced the maxium advance as 59D metro has to much static advance up front he also changed the rate of advance by basically changing the springs in the dizzy so the maxium advance comes in around 3000 rpm as a standard metro advance is a little lazy

Usually the maxium advance for a modified 1300 is around the 30-32 degree mark and all in say around 3-3500rpm mark

As you say its not rocket science you are very limited by what you can change in a mechanical dizzy

Go to the library and get out the Des Hamill book igntion systems, explains what you need to do in there to make changes

Then all the changes are checked on a dizzy machine to make sure it is doing what you want it to do.

I would like to make a mapped igntion system which does not appear to diffcult and its on the list for when teh kids leave home 21 years to go

Huh yeah, I'm starting one of those lists of my own!

Don't get me wrong, I'm not asking for these details because I don't understand timing etc. I believe I have a pretty good grasp on things. I'm asking because this is a topic where you get a lot of things stated as facts, but it can be hard getting beyond opinions. The result of this tends to be people blindly repeating things and getting it wrong because they don't understand the details - 5 pub conversations later and some guy is saying " this guy told me the 123's are crap".
I don't think it's unreasonable to ask for statements such as "the curves are not the optimal for an A series engine" to be backed up with details, especially when we're talking about a product sold specifically for minis. I have no doubt the statement above was made with very good reason. I'm just wanting to know more about the reason

My example of my engine spec was to simpley show how can you buy an off the self dizzy for your engine and get it right out of the box.

I don't believe you can as no engine is the same hence I just got the one I had modfied to work for my spec.

I mucked around for years with different dizzys and set ups with good to average results.

I agree there is a lot of stuff around re whats good whats bad wrong curve etc.

b b bump

bump
123 hav a usb tuneable dizzy now
have these made work easier for dizzy tuners like GR?

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1969 Blue Mini K, 1330cc, Weber 45, polished aluminum roll cage, Race seats, 4 point harness, full rewire incorporating 8 fuses, 6 relays and new headlights just needs tyres front shocks and a windscreen til re-register