SW Temp Gauge Probe Install

I am looking at installing a Stewart Warner temp gauge on one of my cars. Here is a picture of the probe attached to the gauge. The fitting has an O.D. of approx 3/4". Where is it designed to go on a small block? Is there a port already on the motor or do I need a reducer, or...Thanks for any help

Front of the intake is where I put mine.
Reducer probably needed; I think I found one that seated flush at Home Depot.

reducer needed as said.We got them at Advanced .Think they were a few bucks.

Can someone post a picture of the port used? Thanks

If it's a small block Chrysler with a stock manifold the problem he is facing is the opening is for 1/8 NPT which is MUCH smaller than his probe.
More info on your setup will help as there may be a few options

Yes,this is exactly the problem I have.1971 340 stock intake.So I am guessing,without using a bunch of adaptors or T's,I will not be able to use this on a stock intake.

One simple brass fitting will do it on your oem intake, If I cant find the fitting today I will post a pic of it when in use.

I used this fitting on a 70 6bbl intake so I dont see why it would not work on a 4BBL.

Still lets the tip of the sender be in the coolant flow and it seemed to be accurate.

I will see If I have a extra one if you cant source one.

I’ve had to build an adapter before but it’s been decades ago so I can’t point you to the port. Just a task you need a box of fittings in front of you while under hood.

So I need to remove the larger,outside adaptor that is on the sender probe now and find an adaptor to fit the OE sender hole and the smaller fitting on the gauge/probe correct? Thanks Mr Potato

Whatever you use, be sure the fitting the temperature probe fits into has a seat for the probe to seal to. If it doesn't have that seat, you're gonna have leak city going on.

Do NOT use any thread sealer on either part , the senders need to be well ground to work properly

Cab its mechanical not electric Dosent need a ground.

What is the OD of the probe? I believe the Chrysler sending unit ports are 1/8 NPT.
1/8 NPT outside thread diameter is ~.375>
Your probe looks to be fairly large which my not leave enough wall thickness for an 1/8 NPT adapter

From SW gauge install instructions

What did you end up with as an adapter?

OK,I think you are correct with the stock intake having a 1/8" NPT thread sending unit hole.Also correct with the probe having a 1/2" NPT adaptor.I have attached a couple of photos showing I would need approx 1 1/2" deep adaptor(s) to have enough depth for the proble.I would also need an adaptor or adaptors to reduce down the 1/2" NPT on the probe down to the 1/8" NPT hole in the intake.

I see what you mean.Yes,it's approx 1/4" diameter so it would not go down into 1/8" sender hole.I would assume if I had adaptors,etc to make it fit above the intake hole there would not be enough coolant flow to get an accurate reading on top of not being real stable.

Ok, two fittings.... dam the memory sucks at times.

But id not be worried about how much get exposed to coolant, if the tip does it will heat soak as thats all it does in the first place. Had this config going for over 10 years with consistent readings.

I just recalled where my fitting box is so I will go dig out the spare for pics.

Here is where I ran it on a oem 6bbl intake.

Jim, I think your in better shape then you think.

Your sending unit is the same as mine and your starting with a smaller size top fitting.

Figure out your adapter needed as they are made just for this.

https://www.ebay.com/sch/i.html?_fr...w=water+temp+gauge+adapter&_osacat=0

Something like this...

So you are thinking I start with an 1/8" NPT fitting out of the original sender hole,then another adaptor to take it up the smaller of the 2 fittings I have now and do away with the 1/2" NPT adaptor that came with the gauge correct? Let me know what you find for fittings and size.Thanks !!

Looks like we crossed post.Thanks for the link and I'll give it a try.Thanks again !!!

I will find them before the days out.

some of mine

it's been a while since i installed a mechanical temperature sensor.
with that said, the end bulb fitting threads into an adapter that sandwiches the bulb between the fittings, thus sealing the connection. here's where i think it gets a kink.
if i remember right, the fitting on the bulb end is STRAIGHT pipe threads, and so are the female threads in the adapter. this allows for the correct tightening of the bulb to the adapter fitting.
trying to rig up 73 adapter fittings to get to 1/8npt is going to look pretty hoaky at best, and won't be very accurate.
i would look at the water pump housing or intake manifold to see if there is a place that could be safely tapped for the gauge's fitting.
a guy could possibly fabricate a fitting from hex or square brass or aluminum stock, that could T into the inlet heater hose. it wouldn't be that hard to do, plus it would look better than a hardware store plumbing piece.

Good points, mainly on the ugly.

All my fittings came from summit in one form or another. I used two, and the first has the proper taper for the sending unit seal ring, accuracy and sealing was/has never been a problem. The strictest tech tracks never said fix it.

Im sure he can do it with one.

How do I know how accurate the manual unit is installed this way?

Look at this pick, thats the t stat for my 2nd (backup) ele. fan and is said to be a 180 degree unit, the few times ive got that warm, manual unit said right at 178/180. Real world testing, not "I think" or "It might".

You cheat (LOL) and used the heater return opening which I believe is 3/8 NPT. Looks nice though

Only other option without stacking fitting would be to drill and tap to a larger NPT if there is a enough material around the opening to do so.
Welding a bung on may be a possibility or t/sat spacer block with NPT openings. Depends on how clean appearance wise you want it.