Conference terri::cars_uk

    It's a voltage regulator, used to make sure the gagues don't float
    when the battery voltage changes.

  Mark

	Yes, the little box is a voltage regulator. The battery voltage
	goes in to B, and the instruments (@ 10v approx) to I. The case
	must be earthed. It doesn't work unless there's a load on it.

	On the rev counter the spade is the power supply and the two
	bullets the feed to the coil. Can't remember which way round but
	it won't do any harm if back to front. Case of rev counter must
	be grounded too.

	-John

It was on a Ford Corsair.  The fuel gauge went haywire and the temp gauge
wouldn't read below "Boiling" so I took it out to fix.  There is (was on mine
anyway) an adjusting nut, and being an inquisitive engineer, I opened the can
to see what the nut did.  Typical!  Inside was your typical bi-metal strip
with some resistance wire wrapped round it and the adjuster simply varied the
point at which the strip bent far enough to break the contact.  Problem with
mine was that the adjuster had welded to the strip.  Quick file and trial-
and-error adjustments and all worked again....well, sort of.

Nowadays they use electronics!

On this last point, did anyone read the article by Frank Burgess in "Electronic
Business" called "Smart Marketing. And the Dumb Car"?  Fabulous!

brian

Many thanks, that solves the queries for now.  I thought the box was either a
voltage regulator or the indicator flasher unit (since I haven't a clue what the
latter looks like).  As the description given here is perfect, down to the
terminals being labelled B and I, it's definitely the regulator.
The rev counter puzzles me.  The spade terminal connects to a tightly wound coil
of thin wire.  The other two connect to each end of a piece of thicker wire very
loosely looped twice around the tight coil.  Doesn't seem a particularly
reliable inductive link, but I shall try it and see.  Should I connect the
bullet terminals in series with the distributor -> coil LT lead, or connect one
to the LT lead and the other to somewhere else (where?)?

I'm not going to be able to test it for a while, as I still have nowhere to
build a car to put the clocks in.  If anyone knows of a garage/shed/tent not
being used, PLEASE let me know!!

Yours,
Frustrated of IOSG.

	The current to the coil passes through the rev counter. On early
	models you just wrapped the wire around a loop projecting from
	the back!. Also you don't supply the rev counter from the 
	regulator thingy, that's just for guages.

	The design of these instruments is based solidly in the technology
	of the 1920's but the designs didn't change until they were
	completely replaced by electronics simply because they'd learned
	to churn them out very cheaply. A friend has a 1930's daimler
	and the dials on this are as near as dammit exactly the same
	internally as you'd find on a 70's car.

	The guage type instruments often use the incredibly crude, but
	vibration resistant, hot wire ammeter technique. This works by
	amplifying the amount a wire stretches when it gets hot due to
	current passing through it!. That's why the regulator thingy
	works even though all it actually does is turn the main voltage
	on and off, and why it doesn't work if a. There's no load or
	b. There's too much load.

	-John

    now, if it was a Smith's Chronometric tach!!!!
    
    	-Barry-
    

    re: .6

    A friend of mine has one of these on his BSA A10. It is quite impressive
    to see it register 1000rpm with the engine stopped !!!

    The next revolution of the engine returns it to zero.

    Mark    

The E-type has a strange wiring set-up for the Smith's tacho - if the engine
stops in certain positions, the tacho can register over 8000 rpm!  I think
it's something to do with the magnetic impulse system in the distributor.

    re: .8

    The "chronometric" tacho on the BSA is mechanical. It requires the cable
    to be turning for the reading to be valid. When it is working it looks
    quite strange, a bit loke a mechanical clock. It works in units of 500
    rpm I think, clicking up and down as the enigine revs change. I think it
    must perform some sort of sampling to determine the revs at a particular
    instant, because it is possible to increase and decrease the revs quickly
    and fool the thing completely.

   Mark

	I had a car once (ancient MGB) with a mechanical Tacho. This
	was one that was like a speedo but driven from the camshaft
	of the engine.

	The tacho worked fine as such, but the attrition rate of cables
	was enormous. It seemed that the heat from the engine drained all
	of the grease from the cable and after a few thousand miles only
	a wild banshee screeching would announce the need for another
	replacement.

	-John

Having sorted out the speedo and tacho, I now need a set of auxiliary gauges.
Scrapyard searches haven't been very fruitful, so does anyone know of a source
of new Smiths gauges (yes I know they aren't made anymore!)?

I need at least fuel, water temp and oil pressure, half-scale, "angled" chrome
bezels rather than round, viz:

                     |\___________/|   <- bezel
                     |             |   <- gauge body
                            ^
                            |   gauge face

and "old-style" letters/figures, ie with thick vertical lines and narrow
horizontal ones rather than constant-width strokes.
Black background, white letters, and must say "Smiths"...

Alternatively, if anyone's seen some good-condition ones in a scrappy please
let me know...

Scott

Thanks, I thought they only did Stewart Warner, but if they've got Smiths as
well they could receive some of my hard earned loot!

Perhaps they should start a discount scheme for Deccies?

Scott

    ref .11: I have the 30-0-30 ammeter and 0-100 PSI oil pressure gauge. 
    Both mounted on a natty smiths chromium plated instrument panel with a
    space for a cigarette lighter.  The oil pressure gauge is complete
    with its copper pipe and "T" adapter.  Interested?  Give me a call on 
    7774-6243.
    
    John
    

These are not Smiths-specific questions, but here goes. 

Oil pressure gauges: 

- Is the "electric" type inferior to whatever-the-other-type-is? I notice
that the electric types are cheaper and seem to have a much smaller range
of movement of the needle - implying inferior accuracy & sensitivity? 

- Is the difference that the other type has an oil-filled tube running all
the way from the engine to the gauge? 

- If I'm right in supposing that the non-electric type has the long tube is
there a danger over a long period of the tube fracturing due to engine
vibration and movement, and spurting hot oil all over my leg? 

Temperature gauges: 

- Same considerations apply? 

Both: 

- does fitting a gauge mean that the car manufacturer's original warning
light no longer works? (hope not) 

- any makes to avoid?  Are Ron, Tim etc as nasty as the places like Les
Smith and Halfords that sell them? 

    Whenever an electrical guage in my car craps out it gets replaced with
    a mechanical one.  The oil pressure was the first to go and the oil
    temp is the next one to be switched.  The kit for the mech oil pressure
    includes a plastic tube, but I have a -4 Aeroquip line that will be
    going in soon.  That will eliminate the problem of the line breaking
    (or just about anyway).
    
    Fortunately those are the only two that gave me any problems.  I don't
    fancy the idea of fitting a mechanical tach....
    
    Dave

	Some answers to .-2.
    
    	Electric is cheaper to make.
    
    	Yes
    
    	Yes
    
    	Yes, but it'll only be a warm dribble.
    
    	-John

	I've still got my electric oil pressure gauge, they're cheap, but
	the sender isn't and finding the right one was, in the end, too
	much effort.  In the end, I went for a mechanical one, which, as
	Derek points out, fits on a T-piece with the (earth) switch for
	the oil pressure warning light.  So, the answer to an earlier question
	is "no, you don't lose the original switches".

	I don't have an oil temperature gauge, so I don't know anything about
	fitting one.

	Dave

    
    My attitude is - the more guages you've got, the more things there are
    to worry about......
    
    

    I'm busy restoring the MGB dash, because some smoke came from the loom
    after a short circuit in the instruments illumination wire.
    Unfortunately the circuit is fused only near to the
    pilot lamps etc. (Stupid design) Now the loom is repaired by me.
    Dirty job!
    Anyway, I have dismanteled the dasboard, so all the Smith instruments
    are out now. I have taken the opportunity to clean each instrument's 
    front glass, which were "misty"
    Questions:
    - The chrome rings of the instruments obviousely contain some "kit",
      which has become rigid and comes out in small broken particals.
      It appeared to me, the kit was meant for rattle prevention of the 
      instrument's glass.
      * Whith what material can it be replaced?
    
    - All electrical intruments are connected to a voltage regulator.
      Is there any rule to what receptable the voltage regulator should be
      connected? Due to the wire mess, both sender & voltage regulator
      wires got loose at the same moment during the fuel gauge removal.
    
    Hans
                                                    

If you connect the fuel gauge the wrong way round, the needle will either not
move or move the wrong way.  If so, just reconnect the other way round.

To stop the glass rattling, cut a piece of gasket paper into a suitable ring
and put it between the glass and the bezel.  There should also be a
rubber / plastic ring on the other side of the glass to stop it rattling against
the gauge body..

Scott

    Thanks Scott,
    
    There is no rubber ring, but a ring of undetermined material with the 
    same color as the dial itself. (Matt black)
    It is not a ring, but looks like blind ring, preventing the driver
    looking into the instrument's interior.
    There is however  (or should I say was for two gauges) a rubber ring
    between the dashbaord and the gauge itself for noise prevention.
    Two have gone, but I have replacements....
    
    TA Hans

   Do you mean the bit that directs the light onto the dial at night.

   I think it is to prevent the light shining in the drivers eyes, rather
   than to prevent him seeing how the inside works ...

 Mark

    re .26
    
    I don't believe this. I tried to look through from the hole, where the
    illumination bulb normally is fitted, but even without the ring almost
    no light was to be seen from the other side.
    The ring may prevent some unwanted glare from the bulb......
    
    I'm going out for three weeks, I'll let you know, how it went.
    It's holiday time.
    Next topic will be recon of my front struds, California has a hot
    climate, which is not fine for the rubber parts.
    
    Then the brakes and the beast is ready for M.O.T.
    
    TA,
    
     Hans             

Thinking about the fuel gauge connected the wrong way: as it's just a hot-wire
ammeter, it makes no difference which way round you connect it.

Merlin Motorsport don't sell Smiths instruments, or to be precise:

    "We may have one or two sir, but wouldn't you rather have some nice
     Icknield ones?"

    "No, I want a set of Smiths gauges."

    (Salesman turns his back and talks to someone else...)

Scott

    
    Now I'm in this note.... 
    
    I've got a couple of Smiths guages - an oval fuel guage, and a round
    oil pressure guage. Is anyone interested in removing this clutter from
    my desk draw? 
    
    There's also an old voltmeter with a broken needle..............
                           

    Anyone, who can advise how to test the functionality of my temperature
    gauge? During my holidays I've restored the burnt wiring loom in my
    USA MGBT GT. fortunately just one wire was damaged in the loom and
    did not affect the other wires.
    
    At the end there was one unmarked connector feft in the loom, so I was
    able to connect it to the right receptacle on the fuel gauge.
    All worked out with all connected again except the temperature gauge.
    
    1 How can I test the gauge itself. The Haynes MGB manual just shows the
    external wiring diagram drawn, but misses the explanation,
    how the system really works.
    
    2 The "sender" near the waterpump has a riveted receptacle, which 
      appears to be a bit loose. This might be the cause.
      How can I test this sensor?
    
    
    
    Hans

	The Ford temperature sender is a variable earth device, the sensor
	end varying with the temperature of the car.  Cold = no earth, very
	hot = a lot of earth.

1) Remove gauge, battery and instrument voltage regulator from car.
2) Wire them up next to your cooker.
3) Put a pan of water on the cooker and bring to the boil
4) Immerse temp sender in pan and simmer gently
5) Check temp gauge reads 100�C
6) If not, add resistors in series / parallel to calibrate the gauge

The gauge is a hot wire ammeter, so resistors in series will make it read less.

Scott

    
    I would have thought official Jaguar dealers would be able to supply
    a reasonable number of Smiths Instruments - my Series III has
    Oil pressure, Petrol, Water Temp, Battery cond, Speedo, Rev counter
    all made by Smiths and all "standard". 

    

    RE .32:
    
    Yes this worked.
    I have cleaned the receptacle loose bit with cleaning fluid.
    The center (rivit) was showing the variable characteristics.
    Easy top measure with an ohms meter.
    I tried to heat the thing with my wife's hairdryer and it worked a bit.
    I have rerivited the receptacle by hammering a nail to the center
    of the sender and it's tight now.
    
    I did not start the engine yet, because I want to do other things first.
    (Check my questions and experiences with my Lucas alternator)
    
                                        
    Thanks,
    
    Hans
    
    

Is there any "standard" for which way round speedos and tachos should be?

ie which whould be on the left and which on the right?

"Standard" as applied to old British sportscars rather than 1990s
Euro-clone-boxes...

Scott

 Scott,

	The Sprint has it with the Speedo on the left and the Tacho on the 
right, I think that the Escort is the same, but can't remember.


		 Alan
		~~~~~~

Thanks Alan,

Although I was thinking more in terms of the layout in MGs, Triumph TRx, etc...

Scott

Speedo was on the left on my 74 MG Roadster.

 Well you did mention British sportscars, and I took that to include the Sprint,
but yes, I see what you mean. So which side are you having the indicator switch,
will it be the British (ie Right) or the Foreign (ie left) side ? Or is it not
going to be on the steering column at all ? 


		 Alan
		~~~~~~

    In my Frogeye, all Jags I've owned, and my current Escort and Granada,
    tacho is on the left.
    
    Laurie.

re .40

The indicator will be a stalk, as there's no room on the dash for any more
switches!

It will be on the left, for the simple reason that I'd bang my knee on it
every time I got in the car if it was on the right

    Quite frankly, what the hell has the indicator stalk got to do with it?
    
    Laurie.

>>       <<< Note 966.43 by PLAYER::BROWNL "But, why should I grow up?" >>>

>>    Quite frankly, what the hell has the indicator stalk got to do with it?
    
    Well prior to the introduction of the MK3 cortina, all cars were true
    brits and had the indicator stalk on the RH side.
    
    The  MK3 cortina was the first euro-car designed in germany, and those
    foreigners got their way and the indicator stalk was plonked on the LH
    side. Since then everyone (with few exceptions e.g. toyota) has
    followed the euro-norm.
    
    Hence, if your re-building a car to be truly authentically british,
    then the stalk must be on the right.
    
    how many remember the handbrake being on the RH side of the drivers
    seat?. (e.g. morris oxford/austin cambridge/wolsey/riley/MG variants)
    
    
    Richard

re .43

I don't know, but someone asked, so I answered...

Maybe I should forget indicators altogether and use hand-signals...
:-)

Scott

    Yeah, but what has that got to do with which side the tacho is?
    
    Laurie.

In my US spec 1974 Midget, the Tacho is on the left and Speedo on the right.

This is the opposite of my VW and BMW.

-Al

 Scott,

 	It is beginning to look like a case of pick what looks best to you !!!!



	On the subject of Smiths Tachos, the one in the Sprint is playing up,
probably something to do with the 5 years sitting around, but it is over reading
quite a bit, ie it says I am doing 6500RPM when doing 40MPH in top gear !!!!
Does anyone know if there is an easy way of sorting this out, or is it going
to hae to be a case of a new tacho ? By the way it is about right at tick over,
so it is not a simple case of moving the needle to the right place.



		 Alan
		~~~~~~

Alan,

If your tachos anything like mine ("driven" by an induction loop in series with
the igition coil) then you'll probaby find a pre-set adjustment resistor
inside.  Fiddling with that may help.  Or maybe the needle mechanism/spring is
"sticking" at some point?

Scott

 Scott,

	It used to be sticking, but I freed this off, and it is now wildly
inaccurate. I will look for the resitor though, and try to sort it out from 
that. The input to the tacho from the coil actually just plugs in the back, it
is not a wire through a loop at the back of the tacho. (was that the type that
you were talking about ?)


		 Alan
		~~~~~~

Alan,

The wires plug into the back of the tacho... inside the tacho the other side
of the plug is connected to a wire loop.  Same mechanism, different way of
connecting it...

Scott

 Thanks Scott,

	I shall have a look soon anyway, and try to work it out from there, 
hopefully it will be a case of just adjusting that resistor.


		 Alan
		~~~~~~

The obvious way to cure the over reading tacho, is t 
change the cog in the gearbox.

Mark

Mark,

 Have I got the terms wrong, I was sure that Tacho = Rev counter ?


		 Alan
		~~~~~~

 P.S. Haven't had a chance to look at it yet.

Tachometer is the German word for Speedometer

Tachometer is the English word for rev-counter

Clear as mud...

Scott

RE: .last


Oh, then the 'tacho' is on the same side of my english car and my two german
ones 8^).

    
    While fiddling with the Marcos' engine I've broken the hose from the 
    oil pressure gauge off at the engine end (There's a fitting which looks
    like a brake pipe end and this has broken - I think the hose just
    pushes onto this, but I'm not sure - an old oil pressure gauge I had
    had a copper tube, this one is plastic). Some people mentioned a braided
    hose, but this'll probably be a bit over the top (and maybe too
    thick?), but if anyone knows where I can get a replacement part, I'd
    be grateful.
    
    Mark

>>    had a copper tube, this one is plastic). Some people mentioned a braided
    
    Wells Garage, Aldershot, have a parts shop which sell various service
    items and all the other go-faster ;-) bits that these sort of shops sell.
    They certainly stock various gauges, including fittings for oil
    pressure.  I'm sure they do a plastic pipe, with a metal fitting at
    each end.   If that is what you want, I would guess that it is also
    available at Les Smith, or possibly Halfords...
    
    J.R.

    
    Where in Aldershot are they?
    
    Mark

>>    Where in Aldershot are they?
    
    Not in the town centre.
    
    By the 'Prince of Wales' traffic lights, which is the set of lights
    were Baker's (the GM dealer) are situated.
    
    Wells was a JET garage, it was rebuilt/refurbished some time ago and
    is now a BP garage I think.  If you were coming from Ash towards
    Aldershot, on the main road, Wells are on the left hand side, just
    after the traffic lights, next to the pub.
    
    The shop part of the petrol station sells tools, paints, polishes, oils,
    stickers, what-have-you (including gauges etc).  There is also a
    parts counter, which stocks things such as plugs, points, fan belts,
    gaskets and so on for most 'common' vehicles.
    
    At least, being a petrol station, it is open into the evening (although
    the parts counter has restricted times, it's open all day Sunday).
    
    Camberley Auto Factors also have a place round the corner, but I assume
    you know of them (well, at least one of their sites).
    
    J.R.

    
    Sounds like the M.G. oil pressure gauge.
    
    You could always try the M.G. garage in Beach Hill (Tel 884774) and see
    if they have one in stock.
    
    Cheers,
    
    Steve (Still baffled by that ****ing engine!)

    
    Taking this topic onto a new tack.
    
    Does anyone know if it is possible to adjust Smith's Rev counters and
    speedoes?
    
    I tested the rev counter using a halfords dwell angle/rev counter/point
    tester/ ameter meter (thanks Scott), and found that when it read 4000
    rpm via the meter, the rev counter on the car reads 5500rpm.
    
    Always wondered why when doing 4000 rpm in the Midget we were only
    doing 45 mph!!!!
    
    Then when I tested the speedo by driving with another car, and flashing
    lights to get reading at different speeds, I found that the speedo
    reads at least 5 mph too pessimistic (i.e when doing 50mph it reads
    45mph).
    
    Any help?
    
    Steve
    
    PS. I don't think it affects anything, but the car is +ve earth.

>    tester/ ameter meter (thanks Scott), and found that when it read 4000
>    rpm via the meter, the rev counter on the car reads 5500rpm.

    Sounds  remarkably  like  a  6-cylinder rev counter being run on a 4 
    cylinder car.....

    
    Re .-1
    
    Don't think so, its the original rev counter as far as I can see, and
    it is marked as 4 cyl as well as +ve earth.
    
    Its an electrical rev counter btw.
    
    Apparantly there's supposed to be a adjustable resistor inside the
    thing.  I'll have a lokk when I take it appart.
    
    Steve
    
    PS. As far as I know, the tyres, wheels etc are the same size as what
    was origonally placed on the car, so speedo should work, maybe just too
    old!

>>> Sounds  remarkably  like  a  6-cylinder rev counter being run on a 4 
>>>    cylinder car.....


Surely, if that were the case, it would read low ?

Now, if the *test* meter was set up for 6-cylinder operation....


Ian
(or am I getting confused?)