voltage regulator / electronic cooling fan

Post by **bmcecosse** » Tue Nov 18, 2008 8:06 pm

I ALWAYS turn the headlights off - even at traffic lights - and do NOT sit with my foot on the brake either!
But here we go - off subject again i'm afraid!!

linearaudio · Post by **linearaudio** » Tue Nov 18, 2008 8:29 pm

Surely by the time the post is into 2 pages it has the right to have drifted just a bit?

Post by **Roni** » Tue Nov 18, 2008 9:55 pm

Sorry for the slow reply, different time zone.
The fan is from a 1989 Mazda Astina but is a fairly generic one across many japanese cars. It is nice and slim, with the motor in the hub. Being an A/C fan it is smaller than the main cooling fan but it is much more than adequate. Finding it was just a matter of wandering around the wrecker with a tape. That can be quite an interesting time too.
As a matter of interest, I am running an alternator but the fan is only ever on for so short a time that it doesn't get a chance to use a lot of power. The fan is controlled through an adjustable thermostatic switch which made getting it on and off at the right temps easy.<br>

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It is not really obvious either.

Post by **bmcecosse** » Tue Nov 18, 2008 9:59 pm

Looks fine - your grille bars look a bit more 'open' than normal, or is that just the photograph ?

Post by **Roni** » Tue Nov 18, 2008 10:02 pm

Just the photo, they are charcol silver and the shadows make them look a bit different.

Post by **Grahmo** » Wed Nov 19, 2008 12:06 pm

I tried running the car with the radiator half covered (leaving the fan blades on for now) and it has confirmed that the thermostat is regulating the engine temperature nicely at 70oC, not 88 as I was expecting! I have ordered a new thermostat and hopefully this will give me around 80oC and give the engine and my heater a chance to operate a little more efficiently. I haven't been to the scrappy yet a cooling fan but its definately on the shopping list : )

The voltage regulator has settled down and is keeping the battery at 14.4V now, I guess being on the self for 20 years might have had some effect on the points - I probably should have cleaned them up a little but hey its working now.

I am a bit busy with work atm, but I will probably lay out a circuit board over the next few days and order a few blanks. I'll post a message when they are ready as it looks like a few people are interested in making their own digital gauges. So far the project has identified 2 problems with (what I thought was a working car) so it has definately been worth building. I can't say how much the project cost as I had most of the parts laying around, but I am guessing it'll be around the £30 mark.

Re: the slightly off topic subject - Personally I never leave my foot on the brake in traffic (I have an extra brake light in the back window) but haven't thought to turn off the lights. I figure my old sealed beams aren't going to dazzle anyone but it sounds like a good idea if just for giving the dynamo a break. Though wouldn't want to wear out the light switch or more likely forget to turn the headlights back on again!

Anyway thanks for all the pictures / info and replies. A post to this message board is always worthwhile.

Post by **bmcecosse** » Wed Nov 19, 2008 3:39 pm

Good news on the charging. Let us know how you get on with the temperature.

Post by **MarkyB** » Wed Nov 19, 2008 9:43 pm

Surely the reason for having a battery is to take care of short term loads that would be too much for the dynamo?
Presumably a fan that uses more power should also cool faster and be on for less time.

How about a magnet (or 4 ) bolted to the front flange of the diff and a hall sensor to count the pulses?

To use fuel pump pulses you'd have to build in some adjustment as I doubt any two pumps will have exactly the same output.

Post by **Luxobarge** » Thu Nov 20, 2008 11:05 am

Counting diff gear pulses would give you pretty accurate speed info, but would have little direct relation to fuel consumption.

Yes, counting pulses on the fuel pump will vary from car to car, but once calibrated carefully I reckon it would be a pretty good indication of fuel consumption in real time - I actually quite like this idea! Having said that, it's only a good idea if one is really that interested in knowing the fuel consumption in real time on a Morris Minor......

The "counting pulses" technique is how modern car fuel "computers" work - the system knows how many times the injectors have fired, and how long they were open for, and what fuel pressure was present, so can pretty accurately calculate the fuel delivered. Knowing (again, pretty accurately) how far the car has travelled it can then easily calculate fuel consumption and display it on the dash for you. I have one in my car, it's actually pretty accurate, to within 0.2 MPG when measured manually doing the brim-to-brim technique.

Post by **MarkyB** » Thu Nov 20, 2008 6:01 pm

If only I could remember more about the idea of an MPG gauge.
It was in an article I read donkeys years ago probably in practical classics or similar.
What caught my attention was that it needed an SU pump to work and the Minor is already fitted with one

Post by **rayofleamington** » Thu Nov 20, 2008 11:39 pm

From what I know about batteries they send to boil the electrolyte when the voltage exceeds around 13.8V and should never be charged above 14.4V.

Alternators are spec'd up to 14.5 volts... and the battery certainly doesn't 'boil' at 13.8 volts, but it will charge at that voltage.

At least there's someone who doesn't want to immediately fit an alternator! I hate the darn things on Minors as they are a very common failure point.

Post by **Grahmo** » Sat Nov 22, 2008 1:52 pm

Ooops,

I have finally found the spec of the moggies charging system, the dynamo can produce something like 22Amps max (at 2,250rpm), but interestingly the 'compensated regulator' gives a high voltage. At 10oC it gives 16.1 - 16.7 Volts, at 40oC its 15.3 - 15.9V. The charging voltage should drop down when the battery is charged - so it is no doubt current related, this this is probably the reason why I was seeing a high voltage at the fuse box to start with! There is only a quarter of a volt difference at the battery terminals btw. Interestingly at night with the lights on the charging voltage drops down to 14.4V so I guess 'compensated' means giving some kind of charge when your lights are on. Interestingly the battery can withstand a higher charging voltage when cold, so it sounds like the designers took all of this into account when designing the unit - the cleaver people that they are!

Anyway the original regulator was probably working fine, good thing I didn't shell out for new one! I think I'll give it a good service, clean the points up etc and keep it as a spare. Its replacement seems to be working fine so no need to swap it back atm.

Re: the mpg idea, yes it'll need a pick-up from the output of the gearbox to work, and this will also allow me to output mph on the screen as well as mpg. I guess I could pump a known volume of fuel say fill up one of those green fuel cans, count the pulses and this will let me know how many clicks = 1 gallon. Put all the numbers into the processor (along with diff ratio etc), do some maths and the screen can show: Volts, RPM, Temp, MPH and MPG! Not bad eh? I'd better add a few more inputs to that circuit board.

Oh one more thing, I replaced the thermostat with another 88oC one, and it made very little difference, is running at 74oC now. I guess that bypass pipe passes sufficient water to keep the head cool even though the thermostat is probably only just beginning to open. To be honest I'll just have to live with that as I don't fancy blocking the bypass system (which is no doubt there for a reason) but I'll definately add an electronic cooling fan when I find a suitable one. I figure the charging system will cope fine with the short time the fan comes on.

Oh and yes, I definately agree about alternators failing more often than people would think. Where as the dynamo is a serviceable part that seems to last a long time - No Electronics that break and can't easily be replaced : )

Graham

Post by **bmcecosse** » Sat Nov 22, 2008 2:31 pm

Rover eventually realised the bypass was not necessary - and eliminated it in the Metro. With it blanked off you get much faster heat from the heater - and more of it when idling! But have you calibrated your temperature gauge - and exactly where are you reading the temperature from ?

linearaudio · Post by **linearaudio** » Sat Nov 22, 2008 6:16 pm

Drifting off topic a moment- if you bung up the bypass pipe link, do you then need a different thermostat? I've heard talk of drilling holes, but surely the Metro one must therefore have some leak-through built in? Got me thinking now that cold wind is a-blowing!

Post by **bmcecosse** » Sat Nov 22, 2008 6:57 pm

The Metro had a sandwich plate below the stat - with a side feed to the heater. But yes - either keep the heater valve open all the time (best plan for winter) or drill 2 x 1/8" holes in the rim of the stat.

linearaudio · Post by **linearaudio** » Sat Nov 22, 2008 8:25 pm

bmcecosse wrote:The Metro had a sandwich plate below the stat - with a side feed to the heater. But yes - either keep the heater valve open all the time (best plan for winter) or drill 2 x 1/8" holes in the rim of the stat.

Thinks... as I will have to drill out the 940 head for the heater take off, which will then apparently foul the battery carrier, wouldn't I be better off getting a Metro sandwich take off, and using that instead?

Post by **bmcecosse** » Sat Nov 22, 2008 9:08 pm

Don't think so - the old 'screw valve' type heater tap fits in fine. There is also a little stub available - no valve - just stick the hose on the stub and tighten. You don't want to close it anyway! the threaded holes are there already - just run a 1/4" UNF tap down them - and pop a drill through the centre dimple.

Post by **millerman** » Sat Nov 22, 2008 9:55 pm

Try the 'new' type heater valve first on the 940 head; it will clear the battery carrier

linearaudio · Post by **linearaudio** » Sun Nov 23, 2008 8:46 am

Thanks all. Don't know about the heater on all the time-Though it doesn't seem much good at the moment I remember in the brief summery time being glad to disable it! Think I'll go for the modern type valve and drill bit appproach. Apologies for drifting away from the original plot!

Post by **bmcecosse** » Sun Nov 23, 2008 11:51 am

Ahh but you want the water circulation from the back of the head ALL the time - especially in hot weather!