14 replies to this topic

[ECRyder]

Hi

 I have a 1979 850cc Mini with no temp sensor in the cylinder head (or dash gauge) as per spec. I'm fitting an electrical Smiths  water temp gauge.  I took the blanking plug off from the thermostat housing and tried to fit a temp sender but it would not enter the orifice, The thread on the blanking plug and the temp sender do not match, and feeling inside the orifice with the finger seems to suggest the sender would not enter fully. The finger meets cast iron.

Do I need an adaptor, or/and does the orifice in the cylinder head need drilling/tapping? I see there are adaptors that fit into the sump plug hole for the fitment of an oil temperature gauge and wondered if there was the same for a water temp sender into the thermostat housing?

Regards

Chris

[62S]

What sort of sender are you trying to fit? Originally the same one was fitted from the 1970's to the 1990's.

[ECRyder]

It’s resistor type with one spade terminal and earths through the thread/ cylinder head. Male thread.....

[ECRyder]

Not the mechanical type. I’m just after the same set up as on the Mini 1000cc of same period.

[Dusky]

I had the same problem when fitting a mechanical one. The right adapter is all you need. Take both the blanking plug and the sender you have to your local car parts shop, a fiver and you’ll be on the road.

[lordcakes]

Usually the electrical senders will fit straight in. If your sender is deeper (like the bulb for the mechanical gauges) then you would normally fit a te5 adaptor, just to give it more depth.

You mentioned in your first post that you removed the plug from the thermostat housing but the standard sensor fits into the cylinder head below the thermostat. If you undid this blanking cover/bolt you would expect to see some water there as it goes into the head immediately below the thermostat. It may not have been drilled out as 850 engines did not have a temperature gauge as standard.

An alternative is to get a thermostat housing with the tapping for a sender if you don't want to risk drilling the head.

A picture would help confirm the situation

[ECRyder]

Thanks guys Seems my options are a tapped top thermostat housing, a te5 adaptor for more depth, or a sandwich spacer suitably tapped to accept the sender I’ve already purchased ( the type of thread it is I’ve no idea). The last thing I want to do is drill into the head to get the depth I need. An elongated adaptor for more depth seems a good option (te5 or TES??)
I’m guessing if I take blanking plug and sensor to car parts shop, they will tap the blanking plug to accept the sensor thread?
I will post some pics for your comments.
Regards
Chris

[lordcakes]

Te5 adaptor for more depth as per this link http://www.minispare...lassic/TE5.aspx

But, if underneath your blanking plug in the head is solid metal rather than a hole then this adaptor won't work.

[ECRyder]

Hi Guys

Ive decided to go with the tapped thermostat housing. Mini Spares do 12A408. It says Mk 1. Mine is a Mark 4 1979. Hoping it takes my 3/8 inch BSP sender. Can anyone point me in the direction of a supplier for a tapped thermostat housing?

I'm also hoping the inwards end of the sender does not interfere with the top of the thermostat (?). If it does then a spacer "sandwich" may help.

Doing it this way, rather than putting the sender where it should be (where the blanking plug is) does mean its measuring the temperature on the opposite side of the thermostat ie only after the thermostat has opened, but I assume this does not matter, as I'm only interested in the water temperature reading when the engine has fully heated up.

[lordcakes]

The housing you want appears to be unavailable with the major suppliers but seems to be availae in Australia (the shipping might be a bit of a killer). Might be worth an ask of some of the second hand parts suppliers, on here or on Facebook. Also try Tim at minimail (if you want to get hold of him he responds best to phone calls rather than messages or emails)

Just a question, isn't the standard sender a 5/8 unf thread? Have you got the correct size sensor?

Edited by lordcakes, 23 March 2021 - 03:44 PM.

[ECRyder]

Yes a detailed search reveals that 12A408 drilled thermostat housing is available from E bay retailers in Australia. Ive contacted to ask if they post to UK (hoping our "Commonwealth" connections do the trick lol)

As for the sender thread - I bought a  new Smiths gauge here in UK and it came with a sender unit, Asked the seller and he says its 3/8 inch BSP thread. Im fitting it to a bog standard UK 850cc 1979 BL Mini.

Could the 5/8 unf thread be for the Cooper engine?

 

If any forum member does have a drilled thermostat housing they would like to sell please contact me.

 

Regards 

Chris

[lordcakes]

Cylinder head is 5/8 unf on all models. I don't know what size the thermostat takes. But as far as I can tell gtr101 and gtr104 were the sender types for all minis up until 1990ish and they are 5/8-18unf

(https://www.autoelec...snb103-71-p.asp)

Bear in mind that smiths made gauges for many different vehicles, i think some triumphs and Land rovers used 3/8bsp for their temp sensors.

Edited by lordcakes, 23 March 2021 - 04:40 PM.

[ECRyder]

I phoned Tim at Minimail and he came up with a 12A408 drilled thermostat housing. (There IS a God lol). Thanks for the link to the 5/8 x 18 UNF sender unit. Ive ordered one.

You guys are really helpful. Thanks a lot.

Regards

Chris

[Spider]

Seems odd here.

The Thread is 5/8" UNF and the standard Smith style Sender for a Mini should screw right in.

 

Can you post some photos of the Sender and your Head ?

[ECRyder]

Hi Spider

I will post a pic of the thermostat housing when I get it from Tim at Minimail and the sender (transmitter) unit. The housing from Minimailhas a threaded hole in it to accept the sender. I can not place the sender unit into the cylinder head because it is an 850cc engine in a 1979 Mini  (as it came out of the factory) and did not have either a temp gauge nor oil guage as standard. There is just a blanking plug where it would be on a 998cc engine, and no drilling behind it to accept a sender/transmitter unit.