Thinking of installing a aftermarket water temp gauge. Just wondering if i should go with electric or mechanical? Also whats the best place to install it on the engine? If anyone has pics that would be great. TIA

 

You need to tap it with 3/8.
in back of water pump housing
front side plate (driver side) - remove the allen head bolt.
T-stat cover.

 

or just get a electric gauge and splice into the wire just left of the oil sender below the oil filler cap.

 

I went with mechanical.

 

Here is the guage sender zoomed-in.

 

I have an electrical. No need to tap anything. On the drivers side of the motor near the botom under where your AC is or not is a hex head screw that is for draining the cooling system or for a block heater. Take this screw out and an Autometer temp sensor will screw right in.

 

The thread size is close but tap is better since your dealing with 2 different thread pitch. metric vs. npt. Just my $0.02.

 

The good ol' t-sta cover.

 

In the back of the Waterpump housing on the Carb cars is a sensor, it is not used if you have and aftermarket carb.

get the Sunpro adapter set, there is a bushing in the kit that goes right in. and then use an electric guage.

 

I tried both ways and got a 5 Degree Difference???
Why for is that?
And which one will be more accurate?
Just my 2cts worth in a Question
sgieldon
steve

 

What t-stat cover is that from? I dont remember the 12A cars having one like that.

 

Which both ways?

 

found on pre-81 cars, mostly old school rotaries.

 

exactly how i did mine. the wp housing already has taped holes in it wheather it has a sensor in it or an allen head plug in it. the sunpro guage has all the adaptors u'll need.

 

No disrespect but SUNPRO & AUTOGAGE are junks. It will not give ya an accurate reading since the t-coupler is not sealed like the EQUUS, AUTOMETER, S&M. On a stop and go traffic, it will pick up additional heat from the engine compartment.

 

Why for is that?
Not english, but it sounds cool.

 

This is the kit.

http://www.sunpro.com/product_detail.php?pid=16338


It just changes the hole to 1/8 NTP, you can use any guage you would like.

 

Jeff...love that idea. Is the pre 81 thermostat compatable with a 84?

 

how about this universal language.

 

I think '71 to '92 thermostats are all the same. Get a genuine Mazda unit. DO NOT get a Stant. They friggin suck. As for the thermostat cover, or whatever it's called, yeah, '78 and older rotaries had them. Mine already had a BSP plug so I simply unscrewed it and cut new threads in the cover with an NPT tap. It went pretty smoothly. Some covers are undrilled.

The thermocouple fitting shown in my pic is for an Autometer guage. It's fairly nice looking and seems accurate compared to the reading from my MegaSquirt.

 

nice job Jeff. Is that the GLC or ?

 

It is. If it turns out to be too much engine for it, I'll probably just put it in a 1st gen. Talk about too much engine. Well, maybe.

 

John....do you have any better pics of where the screw is? I cant seem to find it.

 

Its a hex head so you will not be able to see it. It is under where your AC would be at. Hope that helps.

 

what's this t-coupler u speak of. u mean the part that secures the probe inside the fitting in the back of the w/p housing? acording to the gauge with fan running in stop-n-go traffic, temp is alittle above 180. since i have nothing to compare it to, that's normal range, right? i think there's some accuracy to it, the probe is actually in the coolant. if anything, it would absorb heat being mounted in the housing. at the time, i needed something inexpensive that would do since putting the engine in the car and breaking the coolant sensor off from paint being in the hole.