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Okay so I've been on the hunt for an adaptor to mate my M10x1 Stack oil temp sender to my 1/8NPT sandwich plate hole, as the one I got from Demon Thieves is way too short (the sender bottoms out after more or less a single turn).

Anyway, looking through the paperwork for my old Autogauge one, that appears to use an M10x1 sender too... so are the two interchangeable? They do look extremely similar. I remember putting a dab of silicone onto my old sender when I installed it and don't remember it throwing up any issues with threading or leaking....

If so I'll just go ahead and do a straight swap, but I'd rather not badger the thread on the sender as they aren't especially cheap!

Can anyone confirm this?

On a related note, will I have to completely drain the oil to swap the senders over? Will it absolutely stream out once I remove the old one and make a big mess? Or will I get away with it if I work pretty quickly?

Many thanks!

Rob
 

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Okay so I've been on the hunt for an adaptor to mate my M10x1 Stack oil temp sender to my 1/8NPT sandwich plate hole, as the one I got from Demon Thieves is way too short (the sender bottoms out after more or less a single turn).

Anyway, looking through the paperwork for my old Autogauge one, that appears to use an M10x1 sender too... so are the two interchangeable? They do look extremely similar. I remember putting a dab of silicone onto my old sender when I installed it and don't remember it throwing up any issues with threading or leaking....

If so I'll just go ahead and do a straight swap, but I'd rather not badger the thread on the sender as they aren't especially cheap!

Can anyone confirm this?

On a related note, will I have to completely drain the oil to swap the senders over? Will it absolutely stream out once I remove the old one and make a big mess? Or will I get away with it if I work pretty quickly?

Many thanks!

Rob
No, they are not the same. 1/8 npt. is 28 tpi. M10x1 is 1mm. pitch which equates to 25.4tpi. The thread form is also different, pipe thread is a Whitworth type, metric is more of a saw tooth form. The diameter of 1/8 npt.is also smaller at 0.3825 ins. which is 9.72 mm.
Regards Geoff Peace.
 

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This is a good chart
http://mdmetric.com/tech/thddat19.htm

As you can see, the dimensions are very close to M10x1, technically not close enough to be good for either parts so it will be a bodge but may very well work okay. Up to you but both threads will suffer damage.
 

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Discussion Starter · #4 ·
I understand that they are not technically the same thread, but simply asking if they are close enough to be interchangeable as a "quick fix" seeing as I am so far unable to get hold of the necessary adapter.

From those figures they do look extremely close, and as the thread depth on the sender is only around 6/7mm I cant see it being dissimilar enough to properly chew anything up?

I probably wouldn't even be considering this had I not found out I may have accidentally done it already previously!
 

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I think you'll get away with it, be careful as the NPT is a tapered hole. Make sure everything is really clean and degreased as far as possible, add a dab of sealant all round and hope it doesn't jam up before you get a good seal.
Had a quick look on DT and found this
http://www.demon-tweeks.co.uk/motorsport/gauge-pipes-adaptors/lma-gauge-sender-unit-adaptors
which is too short, have you tried hydraulics companies like Pirtek? I would offer to make you one up but I don't have the necessary taps or dies


Mess wise, the only oil that you would lose would be from the filter I presume. It's gonna get messy
 

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tbh it could all end in tears with an oil pressure/temp send off - if it blows out the sender because the thread is knackered then you could quite easily end up loosing oil pressure instantaneously which by the time you've noticed the dial dropped may well be too late if you're giving it the beans at relatively low rpm... just my two pence.
 

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So, funny story:

I decided to give it a whirl yesterday. I smeared a load of instant gasket around the thread of the new sender, and placed it, along with the necessary spanner, right next to my head as I laid under the car. I began tweaking the old one off, fully prepared for the impending gush of oil to cover everything in close vicinity, up to and including my eyeballs, as I fumbled to get the new one located. But nothing, just a couple of small drops as I drew the old sender away. A lovely surprised, but a surprise nonetheless.

I have been experiencing very low oil temperatures since fitting my thermostatic oil cooler sandwich plate, and some erratic oil pressure figures from the sender located in the other sandwich plate (alongside the aforementioned oil temp unit).

I have the plate for the senders mounted straight off the block, with the thermo plate on top of that, and then the filter. Would the thermostat stop the flow of oil through the filter like that? I thought it was designed just to direct the flow straight through, and bypassing the hoses for the cooler?

Anyway, with the new one installed (which, by the way, went in easy peasy and tightened up fine, so it appears I was right in my assumption
) I started it up and ran it up to temp to check for leaks. Bone dry. I then took it out for a blast today to try and get it a little hotter but it never rose above 85c ish. The thermostat is set to open at 80 so I'd say this was probably normal seeing as I was out on the open road, not driving too crazily, so the oil cooler would have been working at max efficiency. Am I right? It was not uncommon to see temps of 120c on a good blast before I fitted the cooler though, so it does seem unusually low.

In any case, still no leaks. So happy days in that respect


Rob
 

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in cool weather and on the public road you'll struggle to see oil above 90 with an 80 stat. seems fine to me.

just keep an eye on it. my dad's k series midget went up in flames we think due to a poor fitting oil pressure sensor.
 
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