Temperature sensor

[owenmorris]

Hi, I have bought a electrical temperature gauge and a sensor for my 1961 948cc Minor and I have just fitted a new cylinder head, unfortunately the new head doesn't have a tapping for the sensor is there another way I could fit the sensor and use the gauge.
Thanks, Bernard.

[simmitc]

There are some thermostat covers that have the facility to fit a sender. They don;t record very well until the stat opens but they are certainly OK for when running. Not sure if you can buy them new, but they do come up secondhand in good condition. Another way is to change the head, but you won't want to do that.

[palacebear]

There is a thread on here in the 'Wanted' section with some advice on fitting the type Simmitc refers to. Thread was started about 5 weeks ago. Entitled Morris - thermostat housing... Sorry. Can't copy link for some reason.

[philthehill]

https://www.mmoc.org.uk/Messageboard/vi ... 10&t=67656

see also:-

https://www.mmoc.org.uk/Messageboard/vi ... 13&t=67693

[palacebear]

Those are the ones! Why the heck can't I do that from an android phone???

[Trickydicky]

Here is how I fitted my temperature sender unit.
viewtopic.php?f=11&t=46293&hilit=Temp

[ferret76]

Check with Mini parts suppliers. I have a thermostat housing with a threaded sender hole which works well. The hose to the radiator ends up being at a slightly different angle but causes no problems.

[Pucketsport]

If you haven't fitted a heater then you could do what I did which is to machine up an adaptor which attaches to the cylinder head where the heater tap would normally go. You should have a blanking plate in this location if no heater is fitted. This will give you the worst case temperature which is at the back of the engine furtherest from the water inlet from the radiator. See pic below ( Brass fitting next to the engine steady bracket) This will also give you the actual water temp in the cylinder head before the thermostat opens.

[firedrake1942]

Good idea but why no heater ?

Lovely looking engine compartment Slightly odd looking thermostat housing, mine is domed rather than flat .

[philthehill]

The thermostat housing in the above picture appears to be from a MG Midget/Sprite which has a flat top and the outlet is more horizontal than the Minor thermostat housing.
Even if there is no heater fitted it is better to have circulation round the rear of the head via the heater tap/outlet and back to the bottom hose. If there is no circulation via the heater tap/outlet the coolant at the rear of the head is totally reliant on the pump pushing the coolant round the rear of the head and that does not always happen - one of the reasons why the later water pumps had larger impellors to push more coolant around.

[ManyMinors]

I'm guessing that the car pictured is in Australia perhaps where the optional heater was seldom specified? In the UK most buyers felt it was a worthwhile investment!

[Pucketsport]

Well spotted guys. Yes that is the wrong thermostat housing. It was sold to me by Moss as the correct part for a Minor and as Phil correctly pointed out, the angle of the outlet is wrong for a Minor. Since this photo was taken I have refurbished the original domed part and re-installed it. ( see below)
Also correct is that this is an Australian built car ( I'm Australian) and it never had a heater. Funny thing about Australia is that although it is perceived as a warm climate , and it is in Summer, we get really cold miserable winters in Melbourne so a heater is still a good idea.
Agree with you on the circulation issue Phil and if I find the water temp gets a bit too high , I might do what you suggest and allow the coolant to flow out the adaptor and to the bottom hose. My only concern with this would be that the water pump would draw coolant from this additional source and the water would be hot whereas with a heater there would be some cooling of the water before circulating back to the engine. I would need to restrict the flow to prevent too much recirculating of hot water in lieu of cooled radiator water.
The engine will hopefully be started in the next week or so for the first time since the refurbishment started 5 years ago, wish me luck.
Sorry I couldn't be of help in the water temp sensor positioning.

[firedrake1942]

Good luck with the 'fire-up' and let us know how it goes. Piccies please of progress and when complete. There are often heaters and the matrix attached on e-bay if you really want one, perhaps close to home in NZ or Aus. Costs from UK may be prohibitive, but you have Minor magic down under who have parts I could not get in the UK. Looking at the car it looks like an earlier Minor 1000 which would have a Smths round heater.

Lots in UK but could not see any from ebay.au

https://www.ebay.co.uk/sch/i.html?_nkw= ... eName=GSTL

[philthehill]

Pucketsport
The adapter fitted to the rear of the head and the internal diameter of the pipe from the adapter to the bottom hose will act as a self imposing restrictor without installing a purpose made restrictor.
The hot water from the back of the head will mix with cold water from the bottom of the radiator so that when the water passes back through the water pump it is cool. Any excessively warm water will be passed through the thermostat to the header tank and back to the radiator core for cooling.
The Minor is sufficiently over cooled so as not to build up a cycle of warm, warmer, hot, very hot and boiling water and so on until the engine seizes.
I have fitted a pipe from the heater take off direct to the bottom hose fitted to my Minor to ensure that the rear of the head has sufficient water circulation. I have no requirement for a heater.
Good luck on the engine start up.
I would advise that you do not fit the plugs until you have good oil pressure plus 30 seconds to ensure that oil is fully around the engine especially before the crankshaft bearings become loaded.
Also fill the oil filter with oil before turning over the engine. Easily done as you have the spin on filter fitted.
Phil

[myoldjalopy]

Yes, I too was supplied the wrong MG Midget/Sprite housing but as it does the job I just left it there........seems OK, even if the angle is different.

[philthehill]

The different angle can in the long term play havoc with the top hose and radiator inlet pipe.
There should in practice be a straight connection between the radiator and thermostat housing so as to have absolutely no stress between the two.

[myoldjalopy]

Hmmmmm.....I did wonder about the hose itself but not the rad pipe. Would have thought that the rubber hose would just bend. Too late to go back to the supplier now as it was over a year ago. I should have complained but needed to get the car back on the road in a hurry and thought 'It'll have to do.'. Surprised they should send the wrong type - if they didn't have the right one they should have said so
Maybe something for my Christmas wish list.....

[philthehill]

The hose will bend but it will put the top hose pipe in the radiator header tank under stress leading to cracking and at worst breaking out of the radiator header tank. The metal forming the radiator header tank is not that strong.
Perfect alignment between thermostat housing and radiator inlet pipe should always be the aim.

[Pucketsport]

"I would advise that you do not fit the plugs until you have good oil pressure plus 30 seconds to ensure that oil is fully around the engine especially before the crankshaft bearings become loaded."
Thanks for the advise Phil, I did this and got good oil pressure. I have fitted a combined oil pressure water temp gauge ( mechanical by smiths) . The gauge seems to go up in little jumps rather than a smooth increase , maybe that's because its mechanical ?

[Pucketsport]

Unfortunately things haven't gone well with the planned engine start. I filled the system with coolant only to find a puddle of coolant under the engine the next day. This engine has had a complete rebuild with no expense spared. It seems that the coolant has seeped up through the cylinder head studs !!!!! I am close to having a nervous breakdown with this car. It seems there are quirky issue with just about everything ( even for a car built in 1957).
Was I supposed to use some sealant on the cylinder head studs ? By the way the Haynes manual for this car is the biggest heap of S..t. The book has helped me with next to nothing in the way of technical advice. The photos look like black smudges on the page.
Apologies for the ranting but seriously nothing has been easy on this build. And I've built several cars over the years.
To make matters worse the spark plugs were loose in the engine as I was planning one last oil pressure check before starting and the coolant has seeped down the plug hole ( how much I don't know)