13 replies to this topic

[ChrisDowning]

I’ve got a 1275 (well......1380 to be honest) Carb car. Engine is from a Metro I’m told.

The coolant sensor has never been fitted in the head as this is still undrilled and intact.

Instead, they fitted an in-line temp sensor housing in the top hose. Yep, you can imagine there isn’t much space and there’s a bit of top hose origami going on!

I’d rather not drill and tap the head at this point as I’m not that confident.... especially after reading various posts on various forums about thread sizes and depths etc

Question..... is there anything wrong with drilling and tapping the thermostat housing sandwhich plate and use the original mini type sender? (I haven’t measured it yet)

I see that you can get one already drilled 10mm (or the most recent ones from Xpart weren’t drilled but do have the square plate on the cast ready to drill) to fit the more expensive sender unit.

I am thinking of using the adapter from Minispares and using my original wiring. I feel more confident in drilling and tapping a £30 sandwich plate rather than a £500 head.......

Appreciate your help as I start my Mini journey ?

[cal844]

If it works keep it as it is,

If it doesn't work then yes you can drill the head for the mini sender.

To drill the head you'd ideally need to remove the thermostat housing and then drain the coolant before you drill.

[Spider]

There is a Thermostat Housing available that had a Temp Sender hole in it.

 

They were fitted to a small number of early Minis and I think some of the Morris Minors and A/H Spites / Midgets.

 

It went under Part No.12A408 if you want to do a search.

[ChrisDowning]

Thanks guys. Like I said, the most common sense approach would be to drill the head. Use minispares adapter and away I go.

But I’m extremely nervous about drilling into the head.

The reason I’m needing to have a look at this is:

1. Needed to swap out the water pump as there was signs of a leak.
2. Needed to swap out the fan as it was cracked and had damaged find
3. Thermostat housing gaskets looked like they had previous signs of a leak and had been gunked up.
4. Top bypass hoses were a mess with joints and all kinds of ugly nasty mess.
5. To fit this temp sensor housing the top hose was bent at a pretty crappy angle and was restricting flow.

So I’ve replaced the water pump and can. Cleaned up the pulley, rad housing etc. I’ve replaced the thermostat housing and replaced all the gaskets.
I’m replacing all of the hoses with a Fletcher silicone set. Replacing the heater valve and tidying up the bypass hoses etc

I can see the sandwich units in minispares that now need drilling and tapping.

So I was wondering if the housing was a good place to put it rather than drill the head.

[cal844]

There is a Thermostat Housing available that had a Temp Sender hole in it.

They were fitted to a small number of early Minis and I think some of the Morris Minors and A/H Spites / Midgets.

It went under Part No.12A408 if you want to do a search.

The 1990 to 1995 UK spec carb cars had a vacuum takeoff in a similar location, it was for the charcoal canister.

I'm pretty sure I have an image somewhere that I can post, give me a few minutes

Edit:: couldn't find my exact picture but here is the Minispares.com link

P/N:: PEQ10010

http://www.minispare...c/PEQ10010.aspx

Edited by cal844, 01 October 2019 - 08:41 PM.

[cal844]

Thanks guys. Like I said, the most common sense approach would be to drill the head. Use minispares adapter and away I go.

But I’m extremely nervous about drilling into the head.

The reason I’m needing to have a look at this is:

1. Needed to swap out the water pump as there was signs of a leak.
2. Needed to swap out the fan as it was cracked and had damaged find
3. Thermostat housing gaskets looked like they had previous signs of a leak and had been gunked up.
4. Top bypass hoses were a mess with joints and all kinds of ugly nasty mess.
5. To fit this temp sensor housing the top hose was bent at a pretty crappy angle and was restricting flow.

So I’ve replaced the water pump and can. Cleaned up the pulley, rad housing etc. I’ve replaced the thermostat housing and replaced all the gaskets.
I’m replacing all of the hoses with a Fletcher silicone set. Replacing the heater valve and tidying up the bypass hoses etc

I can see the sandwich units in minispares that now need drilling and tapping.

So I was wondering if the housing was a good place to put it rather than drill the head.

I posted an edit to my previous comment with a link to the one you need, as long as the thermostat is clear of any sender it will work.

Hope this helps

[ChrisDowning]

Thanks Cal ?

[ChrisDowning]

There is a Thermostat Housing available that had a Temp Sender hole in it.



They were fitted to a small number of early Minis and I think some of the Morris Minors and A/H Spites / Midgets.

It went under Part No.12A408 if you want to do a search.

The 1990 to 1995 UK spec carb cars had a vacuum takeoff in a similar location, it was for the charcoal canister.

I'm pretty sure I have an image somewhere that I can post, give me a few minutes

Edit:: couldn't find my exact picture but here is the Minispares.com link

P/N:: PEQ10010

http://www.minispare...c/PEQ10010.aspx

Hi, yeah I saw that but also saw that they’re out of stock.

I’ve gone for the sandwich plate for now and got the 10mm diameter sensor....... but I’m probably going to drill and tap the larger original sender of it fits.

Cheers guys

[Ethel]

The original head sensor is 5/8unf. I doubt you'll find a 'stat spacer thick enough and it's not as simple as drilling and tapping a hole as the sensor seals on a tapered seat.
http://www.dsnclassi...tapped-5-8-unf/



The other consideration is the resistive properties of the sensor to make the gauge read correctly.

There is a simple solution though. Drill and tap 1/8nptf tapered thread and use a corresponding sensor. Quite possibly the one you already have.

[Spider]

There is a Thermostat Housing available that had a Temp Sender hole in it.

 

They were fitted to a small number of early Minis and I think some of the Morris Minors and A/H Spites / Midgets.

 

It went under Part No.12A408 if you want to do a search.

 

This is a 12A408. They take a standard Mini Temperature Transmitter

 

 

Drilled & Tapped 5/8" UNF with a seat.

[pete l]

Won't that measure the coolant only when the thermostat is open ?

[Spider]

Won't that measure the coolant only when the thermostat is open ?

 

Yes and no. The bleed hole (that was in the thermostats on the cars that these were fitted to) does allow enough coolant to show a reading and it doesn't take long before the t'stat cracks open just the smallest bit. There's also some heat transfer through the housing.

 

But IMO, it is a good option when one doesn't want to or can't drill the head. It's not ideal, but not far from it.

 

The one that Cal linked up is a better option, but I see they are out of stock and they take an odd ball sender. Smiths do have a M10 x 1.0 Sender that will fit, however, the Calibration of it doesn't match the standard Gauges fitted to Minis.

If I recall, (in the Mini Range) these were fitted to the early Super Deluxe and the very early 997 Cooper cars as the heads didn't have a port.

[Ethel]

A bigger concern would be low coolant level causing a sensor fitted that high to read low.

[Icey]

We've got a housing with a sensor drilled and tapped, if you're interested drop me a PM.