RUMCars Forum
General Category => Unusual Microcar Discussion => Topic started by: Big Al on September 30, 2014, 08:36:18 AM
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Bob hit this one on the head. There seems a lack of will in folk servicing the dynostart. Indeed a lack of any real understanding of what this very microcar unit is all about. If you take the trouble to read the manuals, you will find within a recommendation to service the unit, and keep the dust down.
Remaking a dynostart now would be an expensive option, and age catches up with all things. Looked after these units have a long life, but some of the poor old things I have had to tempt back to life will inevitably have a shortened one. Unfortunately the sort of people who need to get with it on dynostarts are the same people who tend not to research their cars, and will not be on forums or in clubs. Fortunately I have found that one donor dynostart can be used to repair quite a few botched up ones to keep the kettle boiling. Such is the situation with dynostarters though I am now reluctant to pass on my spare Schmitt units as it is the part that will ultimately see the cars leave the road.
As to LED and dynostarts. I can see the advantage here. That is driving with lights on to be seen without forever creating a large drain on the battery. A bulb tends to be invisible unless lit so even here they fill the bill. However fitting LED is not an excuse to ignore the dynostart, the heart of your cars functionality.
Siba themselves produced a series of very good single page folded and A1 poster size dynostart guides. I recommend obtaining one, preferably the correct one for your car - reversing / non reversing. I imagine someone will be selling copies but I have seen genuine ones at autojumble so they must appear on eBay.
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Dear Al and Bob
I agree that you need a healthy Dynastart to begin with, and LED lights are not a cure for a duff Dynastart. My point was that most of the engines with Dynastarts were designed for use with motorcycles, that had one head light, one rear light and no indicators or windscreen wipers. By installing them in a small car with two headlights, two tail lights, a windscreen wiper and indicators, on a cold wet winters night the drain was probably more than the output, resulting in a constant battery drain. This would also have applied to non Dynastart engines as well. With modern roads at night, 6 volt candles can get lost in the glare, and brighter, low wattage LED lights would be safer, and allow the little 6 volt battery to last longer. Of course most sensible Microcar owners choose not to drive their cars at night to avoid this situation.
It will not be long before all filament bulbs will be hard to get and LED bulbs will be the norm and cheaper.
I feel sure that others will have an opinion on this matter.
Chris Thomas
Rumcar News
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6volt candles? All dynastart systems are 12 volt Chris. That's what makes them good and fit for the task.
I feel that the demand will be sufficient among classic car fraternity to warrant constant manufacture of traditional bulbs.
I'm not against the odd light modification when it gives the owner more confidence to drive the cars but so far have not found the need for this one. For example, I drove the Schmitt from Bath to Hornchurch with all lights on, some wiper/ indicator use and the battery was as good as when I started out. All down to maintenance. Still, if we find you are right and we can no longer get the bulbs I will be grateful for these guys blazing the trail with led conversions.
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This was why most microcars had 12 volt systems, not 6v, and the dynostarters were rated by the need to start the engine, where maximum current can be very high, rather than the needs of charging. So a well maintained Schmitt can have its lights, sidelights and screen wiper on and maintain a charged battery. The margin of error is small, many Schmitter has had a glowing charging lamp winking at him, but these are microcars, and thats what that means. It is enough to get the job done. Its the deal. Its what one embraces as a microcar owner. If you do not like this then these are not the car for you. Add to this that in 1960 there were many cars still relying on semaphore indicators, vacuum wipers, and without heating to boot, and the package for the price was very good. For my own experience I never suffered a failure to get home for want of charging, save when I left for Kettering with a known defective dynostart and a promise of swapped batteries that was not fulfilled. I cannot say the same for Minis, Austin Healey Sprite and other, allegedly, better cars.
The specification works if it is maintained. What has happened is technology, legal requirements and driving habits have changed. The chief danger in driving some of the Microcars at night is that the small and closer coupled lights look like a car farther away than it really is to young numbty in his turbo terrific. He is therefore taken by surprise on suddenly finding a small car in front of him rather than a larger one, perhaps, in his mind, with a small trailer on some 50 yards further up the road. Such is the quality of driving now that this is a consistent dangerous situation as folk rely on the car to resolve the situation, rather than driving skill. I am not sure brighter lights resolves this issue of perceived size/distance away.
As to not driving your microcar at night. Ignoring the puddle jumpers, well that just means you really should not be owning one. Certainly spells death for any kind of meaningful pub night activity. You have to route find and learn to drive better to maximize the advantages of the Microcar. Sadly that is not a great help to the plain slow, but a Schmitt, or Goggo, is a perfectly legitimate car to drive at any time, if you understand it's, and your own, capabilities. Things like NSU and Bond Bug really should never be on trailers, at all. Now ask me about rally attendance and campers again? Its all tied together. If you do not use it, you will loose it.
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Really sorry but the thread should be DYNA start - otherwise all this important info will be untraceable in the future
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Need a naming secretary. I thought putting it in its own subject might be enough, after being told not to digress, that is a BSA isn't? ;D
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Richard has a good point. Hope you don't mind Al but I changed it to dynastart so it will show up in a search in the future.
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Quite right, Richard: Dynastart!
It's true that, for many microcars, a well-sorted Dynastart will run all that was intended.
Problem is ....
Some micros (eg my Bond Mk A) don't have a Dynastart - and the magneto was designed for one headlamp and one tail-lamp (of ... wait-for-it ... 3W). Even when new, it outran its motorbike origins by running TWO headlamps, one tail-lamp, and occasionally the wiper. Nowadays (for driving safety) it runs two headlamps (up from 12W each to a frightening 18W), three tail-lights (incl number plate, and all at the equivalent brightness of 6W), a brake light (equivalent to 21W), the wiper, occasional flashers, and ... a whopping great fat starter motor. With a big battery, it lasts a week when used daily, and LEDs on the smaller bulbs help achieve that.
Some micros (eg my Bond Mk G) have a Dynastart, but even when new rather outran its capabilities. The twin wiper set-up, on its own, takes half of the available 8A-ish of output. The (added) electric fuel tap takes a continuous amp, the radio, dashboard clock and satnav a bit more, and 24W headlights (which Bond introduced because the Dynastart couldn't deal with the 48W bulbs on the Mk F) just aren't enough to see by - you can be seen, sure, but on a wet night on an unlit road, you can't make out the road surface in front of you! Hence the uplift to some decent light output, and the balancing action of LEDs in other lights.
I like driving a 1950s or 1960s car .... but I drive it in the present!
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Oh all your making it worse :D the Digress was Triumph , the BSA was a Sunbeam - as indeed you are yourself ;) anyway I am up in Glasgow this week and am sure they would call it the Dinna Start :)
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Dear Bob
Thank you for correcting me regarding the voltage. All my motorcycles were all 6 Volt and even my first VW Beetle was 6 volt. Just goes to show I have never owned a Schmitt, Scootacar, or any other car with a Dynastart.
I do take Big Al's point about the lights being close together looking as if they are further away. An unsolvable problem made worse by dim lights.
How else can old car electrics be improved by modern electronics?
Chris Thomas
Rumcar news
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How else can old car electrics be improved by modern electronics?
(1) Modern batteries - "maintenance free", and of decent cold starter amps. (The - new - 6V lead-acid version I first had on the Mk A was huge, 57Ah, and had a cold-cranking output of 450 Amps. When it split (!), I put in a gel version, about half the weight and size, same Ah rating, but with a cold cranking amps output of 800 Amps (!)
(2) Electronic ignition (where available). I've put a full (contactless) version in the magneto on the Mk A, but haven't found a reliable contactless version for the Dynastart engine on the Mk G. I did try a "spark booster" version (which still retains the original points), but it's the points I want to get rid of.
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The Bond Mk A harks back to even earlier and more simple times, still. Though it is a Microcar, of course, perhaps the first. There is no way to be safe with the original lighting, which look very much like a bike.
As to later Bonds not having dynastarters that kept up with the demand, that is a production error as dynostarters are available with more powerful charging systems, and regulators to suit. See Goggos 250/300 compared with 400. But is this actually true? I do not recall a problem, but my mileage is scant in Bonds.
Do not blame the dynostarter if you cannot run non standard extras, either. The choice is yours. I prefer to know where I am, than be told. I prefer to listen to my car, than someone bleating on the radio. It goes better, in both cases. As to electric clocks and taps, blimey, its not a microcar, its a Rolls Royce! I see why LED might be appealing, but are all those extras strictly needed, modern or not? Ho hum.
Lights on some microcars can be altered to combat the shrinking effect I highlighted. Heinkel and Goggo for instance have the indicator parking light on each indicator on the far outer edge of the car. A slight change in wiring alters these into permanent sidelight side-markers. Even the standard 3w bulbs are enough to create a question of the size of the car in the dark. The additional lighting looks most odd. Take to LED and the increased brightness might yield more results. The Schmitt already has extra sidelights over its continental brothers. Not a lot you can do, but light up the rear of the dome. Again the oddity of lighting gets a second look. Like I say, its about knowing your cars and using them to best advantage.
Bigger battery power is welcome but only of use if it is charged. On a good run at night, or in rain, the effect dissipates over distance if your dynastart is leaning on the battery. Nothing changes that. The bigger battery is a boon to the little used, short hop Microcar though.
Electronic ignition. Great till it does not work, then your stuck. The old Sparkrite works well as it keeps the points, reduces the spark erosion but can be turned off at will. The only advantage in electronic is really if there is a proper set of mapping available for improved performance. We are back at uprating engines, more power and all those arguments. Strange that it is the original cars that seem to be the ones that keep working. Says it all really.
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I looked into LED lamp replacements because I wanted to fuel inject the engine, and that means an additional 40 watt load on the system.
The main draw being the fuel pump which uses about 25 watts and the heated lambda/oxygen sensor, the latter tails off in consumption as the exhaust from the engine removes the requirement for electrical heating.
By replacing rear lamps, numberplate, speedo and front pod lights with LED units, that liberates about 17-18 watts immediately, at no performance loss, and the units are just plug in replacements- happy days.
Indicators can also be replaced with plug in units, but you will either need a thirsty resistor wired in parallel (negates much of the improvement in low current draw) to get the flasher to function or replace the unit with a solid state example that doesn't require significant current draw. So some owners may wish to retain incandescents for these units, as indicators are usually only on for a brief period.
Headlights are another issue. Not much commercially available to convert pre-focus headlights to LED operation, and nothing that really works as well, so that means rolling up your sleeves and getting your hands dirty. Very high output LED's are inexpensively available. and have improved exponentially in the last couple of years.
The Cree range of LED's are favourite, the best of which are capable of 200 lumens per watt (about twenty times better than an incandescent). The snag with them is they are rather fiddly to work with being tiny, and also they require heatsinking. The best of the units currently chuck out about 2.5° C per watt, so if running at rates adequate to give luminance outputs of say a decent halogen lamp then you are likely to need a heatsink capable of dispersing about 7.5° C of heat. Quite a modest sized chunk of metal.
If you want to ramp up the unit for truly dazzling performance then you can easily quadruple that requirement, which would mean fairly large passive heatsinks or smaller units with active cooling, e.g. fans.
Regarding batteries, the range of Lipo LiFE po4 batteries is worth a glance. These have about five times the energy density of a traditional Pb technology, can be recharged at higher rates and hold their charge for years even when left untouched. The main snag is their high cost, but if you're going to keep a car for the foreseeable future, the expenditure may repay itself as the cycle life is more than four times that of lead acid.
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are all those extras strictly needed, modern or not?
Well, no. For almost all of us, the whole microcar is not strictly needed!
But I enjoy having the cars, and driving them - my way.
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If you're willing to break out the soldering iron, there was an excellent electronic ignition system featured in two parts in Everyday Practical Electronics magazine back in February and March of this year.
http://www.epemag3.com/projects.html
Not only does it dispense with the points, but it also gives you programmable dwell. By making it yourself you will gain an appreciation of how it works, and also you can fault find if it goes wrong, which is fairly unlikely with modern electronics, as they're very much more rugged than years ago, especially power transistors.
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From the brief details as linked, that appears to deal with the stages beyond whatever you have as trigger (points, optical, Hall effect, etc), but not build the trigger itself, which is the difficult bit to source - or have I misunderstood?
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A trigger is a piece of cake. You can use a hall sensor and a magnet, very cheap and easy to make yourself.
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The trick I csn't get my head round is how to mount the moving parts, and how to arrange for the two sensors not to interfere with each other, to allow reverse.
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The trick I csn't get my head round is how to mount the moving parts, and how to arrange for the two sensors not to interfere with each other, to allow reverse.
replace the advance cam with a new piece that incorporates a small magnet embedded in it.
This would have to be fabricated of course.
Hall Effect sensor gets mounted where the points used to be and so does not move except for adjustment.
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are all those extras strictly needed, modern or not?
Well, no. For almost all of us, the whole microcar is not strictly needed!
But I enjoy having the cars, and driving them - my way.
'nuf said. It is about the enjoyment of the car, when all is said and done.
The LED thing is actually of more general use in classic cars and the benefits are there for pure savings in power, or a cunning plan. Be handy to find an indicator answer rather than a resister that is off the shelf, as it were.
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The 'off-the-shelf' answer to non-resistor fitted led indicators is to fit a replacment flasher designed with LED's in mind. These tend to be relay or fully solid state based instead of the old bi-metallic strip of earlier units.
They are available, but of course it entails an additional expense, plus it's generally a non-standard looking item, for those ultra fussy about originality.
If you wanted to be really trick, you could of course make up your own board designed to fit in the original can!
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Regarding hall sensor triggering for a dual points set-up, I have no experience of those, but would suggest that a bistable relay which switches from one pole to the other depending on which way the engine was started. This would then use either one hall sensor or the other.
Hall sensors are available which don't need an external magnet, as they have one incorporated internally. All you need for a trigger is a bit of steel or iron sweeping past. this could be something as basic as a bit of steel rod bonded onto the cam that originally triggered the points. A proper job would be a new plate, cam with a single tooth worked in.
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The only Hall sensor I have is my wife as she comes through the front door. Anything parked in the hallway and I sense her anger.
Chris Thomas
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Thanks for that - I need to give it some thought!
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Just found these. Similar concept to what i am aiming at, although active heatsinks, wheras I am using passive heatsinks. They're also bit higher output than what I would go for, but certainly lower current draw than filament lamps. They would also need some plates made up to make them suitable for prefocus reflectors, but that shouldn't be a huge problem for anyone with basic bench fitting skills.
http://www.aliexpress.com/item/High-power-car-h4-led-headlight-bulbs-50w-Cree-CXA-1512-led-headlight/1246825521.html