Various additional gauges into an S3

[secondjeremy]

Doesn't the oil temperature sender need to be in moving oil - rather than for example a dead end like a pressure gauge adaptor - otherwise the temperature its going to measure is going to be the temperature of whatever heat conducts through the metal.

[Landrover17H]

I think you're right, only minus a mill, buying the LR part comes cheaper.

Love the pix. You've out-gauged me. A propeller gauge, is that a thing? There I was, about to fix, in front of the mirror - an interior lamp. Where your altimeter lives now; but no, it's a rare thing on the internet: “You know what? You’ve convinced me I was wrong.”

 

Edited June 7, 2020 by Landrover17H

[Landrover17H]

32 minutes ago, secondjeremy said:

Doesn't the oil temperature sender need to be in moving oil - rather than for example a dead end like a pressure gauge adaptor - otherwise the temperature its going to measure is going to be the temperature of whatever heat conducts through the metal.

And the sender response rate will be very slow...  you are following this? The point we're making, hence Gazzer's words in  bar-stock or similar. I'm hoping to find a 1/8 BSP Tee fitting 'off-the-shelf', which with a few fittings can be cobbled in with the banjo, but it may not sit mid-flow. Which is the issue.

Edited June 7, 2020 by Landrover17H

[Gazzar]

Here's an idea: The oil cooler hockey puck for the FFR oil cooler? Get one of those, blank the ports, and drill into the blanks. I've a couple in the container, I'll see if it's viable.

[Gazzar]

Yep, that should work.

[Landrover17H]

I've not seen a 'milly' cooler in the flesh, digging around I've had a look-see at parts diags.  I wasn't expecting 'Puck' to have a Part number, anymore than looking under 'Maltese Cross grill' is going to reveal much - yet looking at the parts, I would think there's a way of cobblin' something. For the others, here what I've found:

[Landrover17H]

I get it.  Our emails x'ed. Vaguely guessed, that's what you meant. Doesn't look  too  'puck-like' on the diagram, but does in the flesh. Yep, that'll fire in. And a drinky your way for said item. Me want.

Edited June 7, 2020 by Landrover17H

[Landrover17H]

One thing that might interest in this, whilst looking into the heated-screen switching I put in a fuse-panel. I had it switched such that it becomes live only when the engine runs, ie fired-up via a relay to supply coolant fan, heated screens, USB chargers and all accessories found redundant or best powered down, without engine running. It required a oil-pressure switch change. Details in the diagram. I do these drawings, else I'll forget what I've done, but others might see it as useful.

 

Edited June 7, 2020 by Landrover17H

[Gazzar]

Useful! I might use that for the lightweight.

For the truck I  used a defender heated front screen relay, does same job, only works when the oil light is out, and gives you 12 minutes.

 

[Landrover17H]

Gazzer:

Your centre console: Looks like you've got the real thing, a proper  Land rover part. On mine, there be a gap (roughly under, and a tad to the right of your fog lamp switch). Mine's a pattern part, bought blank to be drilled as required. Never seen the proper thing installed. Do you have anything there to take up the gap? Else I can see losing keys etc, or anything rolling via the parcel-tray into the console, or the 3 x gauge plastic housing. How have you done yours, or is it left to chance?

[Landrover17H]

You've set me thinking - reckon this'll do it too. Not as tidy as the 'puck' idea, but it'll go.

[Anderzander]

8 hours ago, Landrover17H said:

 

Bit of a tangent - but I just had to buy No.5 .... they’re not cheap.

[Landrover17H]

I can't believe the price of the whole assembly, cheapest I could find was £160,  sections of it selling at 'ridiculous' wouldn't surprise me. Gazzer's suggestion of the 'puck' comes out best. Thank you Gazzer. After some daft prices, I've struck lucky. Blandchards have these at £25 delivered which added to the bill for all the other parts makes this a £70 job,  still  a fair bit for a oil-temp gauge. Yet, we do these things, you can pay double that for a gauge alone.

In my digging I found another bit of info, this time on classic Smiths gauges, shame I can't give get the whole manual, but this helped me test mine. Seems Smiths have several types, working in different ways.  Smiths BT TC & TE Types. My Snipe Smiths temperature gauge is a TC (see TC prefix on gauge - this piccy taken before I butchered it!), whereas if I have it right Land rovers have BT Type gauges. They're wired differently dependent on flavour, I consider myself lucky to have found this info. For your delectation,  'some' pages of the 'Smiths Gauge Service manual', sadly only temperature versions. Here's a typical page along with the PDF of all I've managed to dig up:

01 Smiths Temp Gauge Manual BT TC & TE Types.pdf

Edited June 8, 2020 by Landrover17H

[Landrover17H]

The dots you'll see on the gauge-scale are calibration points. See: http://www.mgb-stuff.org.uk/fuel.htm

As I said previously, they look good yet classic Smiths / Jaeger voltmeters are not up to the job. I'd never seen a voltmeter that wasn't polarity dependent before. Using heaters, they're next to useless, suggest if you want the 'look', cobble in a modern 'moving-coil' movement into any older gauge body.

Edited June 8, 2020 by Landrover17H

[Landrover17H]

Right, next on the agenda is to get a variable resistor on the 'T' terminal of the Humber Snipe Smiths TC type gauge and twiddle about to find the  resistance value it likes to display mid-point - 85 degrees? Then find the sender which puts out that value at 85 Degs. Most classic gauges are resistive. Our leather-elbow-patched friends on the MG & Triumph owner sites have the most info. Ohm's Law at the ready,

The formula for calculating voltage drops etc; 

R2= (Vout)(R1)/(Vin - Vout)=

And if I can't find a well-matched sender, I'll get the nearest I can find, and break-out the 10 Ohm resistors, and the perennial solder/shrink-wrap, until there is.

I'm hoping it's as simple as a stock MGA/MGB/Spitfire/Stag sender? Leaves me to wonder, before they allow me to have one, are Tweed /string-back gloves compulsory?

However I also run 'gas', in fact mine's rarely running petrol these days. My gas cylinder has a sender (AEB 806) which is rather more modern. Sends 0-5V; getting that to display on a 10V Stabilized Land rover S3 resistive-gauge is going to be a head-scratch. Yup, do me favour, a 0-5V fuel gauge now adapted to show on a Smiths classic. Oh dear, rather more than Ohm's Law. I march on.

Edited June 8, 2020 by Landrover17H

[Landrover17H]

Well, with Gazzer’s input:

I’ve a decent and relatively easy way to lay-in a temperature sender. Thank you again Gazzer.

Here’s where I’ve got to so far.

More fight than I thought it warranted, these things just are, sometimes… best I apologise for the grumblin’ from the off. I write thsi for others that may follow. Might save a few blind-alleys, and to think I had this as a £40, 2-3 hour job.

To get a temperature sender (thread: 5/8” UNF) in the oil, a ‘Puck’ 247753 is the way to go. The exit-thread is 3/8 BSP and whilst 3/8 BSP is common enough, the standard fittings found at your everyday hydraulics/plumbing suppler (to get to 5/8” UNF) leaves the sender in a long oil ‘cul-de-sac’ - out of the flow. Thus what we need is a short reducer - known as a gauge-adaptor.  

Edited June 27, 2020 by Landrover17H

[Landrover17H]

Thing is, 3/8 BSP / 5/8” UNF gauge-adaptors don’t readily exist. Spent  a day, looked everywhere, eBay, Amazon, Motorsport suppliers etc…. nope. Everything is NPT or Metric.

The adaptor 592017 which comes with the puck, is 3/8 BSP, but isn’t 5/8” UNF ‘tother end. Having already stumped up for a heap of parts, based on this route, I was worried I was set to pay for custom-machining or abandon.

[Landrover17H]

As above, eventually found my gauge-adaptor. Merlin Motorsport had one for a £15 delivered - I spent a day struggling to find it, time considered, this came far more costly than its £15.

Seems obvious now, but I kinda had one all along.  I’ve a metric engine with metric threads, thus, in the head I had a metric gauge-adaptor ERC8973 only it’s M16 X 1 / 5/8” UNF. Most of you will have the S3 gauge-adaptor, 568457 which is found in S3 heads. It’s a £35 part, but it’s 3/8 BSP / 5/8” UNF. Wish I’d known, I’d have paid the extra to have it done in minutes. Turns out  3/8 BSP / 5/8” UNF gauge adaptors may not be common, but they are common to LR. We learn.

Edited June 27, 2020 by Landrover17H

[Landrover17H]

Next obstacle came to be my choice of temperature gauge. To look ‘right’ it needs to be a left-to-right movement with a ‘scale’ or ‘face’ I could cobble-in. Many early 60s cars have this configuration. It's needs to finish as below. Mine came from a Humber Super Snipe, but Austin Westminsters A110 etc also have these. But finding a sender to match proved difficult. These gauges didn’t use a 10V stabiliser, and need the now defunct Unipart GTR102 Coolant Temperature Sender
also known as a Smiths A-TT04, TT4800-00A & TT3800/00A. Intermotor 52700
They’re hard to find, and harder to find that such a thing exists.
They have an oddball output:
32°C = 180Ω (just budges meter)
40°C = 100Ω
77°C = 22Ω
Centre = 20Ω calibration dots
87°C = 15Ω
110°C = 10Ω

 

 

Edited June 27, 2020 by Landrover17H

[Landrover17H]

They’re often referred to as ’transmitters’ even ‘transistors’; rather than ‘senders’ or ’sensors’ which, in context, they are not. This adds hours to searches for the same thing. Cars with  ‘sensors’ etc came in with the late 80s.

To get this info, I was found in Triumph, Mini, MG and Sunbeam Alpine forums. However, you could wonder why it’s made harder? Reading the forums, it’s frightening how, taught this in school, many don’t grasp the very basic. Turns out, many early Alpines, Triumph Heralds, A30, A35, A40, A55 and pre 1962ish Minis have this temperature sender. Once you know what you're wanting is a Temperature sender for a Austin Gipsy/Gysey/Sunbeam Alpine / Hillman Husky etc, it gets much easier. But it’s knowing….

My time again, I’d have found a later gauge, with Smiths/Jaeger Model Number commencing BT, as does the S3 water temp. gauge. The Humber Snipe TC format gauge is more awkward. It’s not stabilised thus will, to a degree, vary dependent on alternator/battery voltage. Unfortunatley an S3 temperature gauge would look odd, it’s facia would be inverted, and its ‘sweep’ is reverse for the lower segment. Not ideal for the lower segment in the cluster. Find a late 60s, Rootes / Hillman/ Humber etc seem to have this configuration. Smiths / Jaeger BT format gauges have advantages over TC, not least senders are easier to find. If you can't lay you hands on a BT type, below is a Smiths TC install manual. No stabiliser.

My gauge needs 21Ω to read 85°C, so it’ll take a bit of messing with some resistors or a cheapy ‘pot’ to calibrate. That’s next. But then, these old Smiths gauges were never really about accuracy. More an indication of change, once your ‘Normal’  is known.

 

Now a saucepan to gauge-match and see what this GTR102 puts out in Ohms. We march on.

05 Oil Temp Sender Intermotor 5270 GTR10 No Stabiliser Install.pdf

Edited June 27, 2020 by Landrover17H