Water Temp Gauge Question

[AnthonyR23]

Hi.. so I have a new mark 8 fan, finally ordered a spal fan control unit.. cause my fan runs on high all the time right now.... says that the stock setting is for the fan to come on low at 160 degrees and on high at 200 degrees. Which I can adjust.. I have been told that the stock water temp gauge is no good (inaccurate) but I guess I am just going to have to go with it for now.. but I'm looking at this water temp gauge from www.mustangsunlimited.com http://www.mustangsunlimited.com/itemdy00.asp?T1=AM5732+01

It is a Autometer Phantom mechanical gauge. Is this a good gauge to go with??

Other quick question and biggest question is regarding operating temp... I have been told that the correct operating temp is 200 degrees... does operating temp refer to engine temp.. or water temp... I think I read somewhere that the water temp should be 10 degrees less... approx.. does that sound right??? I have emissions testing here so if operating temp is refering to just water temp I would rather it sit at 200 not 190 (10 degrees less) because I think the computer adds more fuel to try to get it up to temp... if operating temp is too low... and that won't help me with emissions... will be too rich. Any ideas??? What water temp are any of you with a mechanical guage sitting at?? or aiming for?? and once I get this gauge.. would you guys recommend a different starting point then the 160 low and 200 high speed????

Thanks

 

[HISSIN50]

I live in the desert so I simply shoot for having water temps at 185*F ish most of the time. When it's 115*F outside, I creep up to 195-200*F (read at the gauge).

There is no 'one-temp' for the cooling system. There are some extremely hot spots and then more stablilized spots further from the chambers. If your gauge (with the sending unit in the stock sending unit location) reads 190-210*F (iron heads), you should be fine.

That gauge you're lookin at is a very nice one. The only thing is to ensure the 6' of capillary tubing will be enough to reach. I cut 6' of cheap electrical wire (like 18 AWG) and run it along my intended route to make sure it will work. It's a lot easier to run a piece of wire during mock-up than to keep running the capillary tubing till you find a good route.

When the engine gets around 170*F, it can actually lean out to bring temps up. Then once it reaches about 185*F, it should be happy and level off. Vristang can probably provide datalogs of lambda feedback but it's going to be moot for emissions IMHO (it's fun theory to throw around but doesnt really matter much on a SD stang in the real world).

Good luck.

 

[LordMustangGT]

I run the Autometer luner water temp macanical and its THE BEST. I have it in the top triple pod on the apiler on my 88 and reachs with no problem, but just barley. But had enough to run it under the intake manifold and still make it look good.

 

[Sicarius428]

You really can't go wrong with any of the autometer gauges. What your operating temp also depends on what your thermostat is set for. I run a 180 in my 5.0 and according to my electric autometer gauge(tapped into the t-stat housing) its aways on the 180 bar.
Kevin

 

[AnthonyR23]

Thanks guys!!! Great Reply's!!!! Around here it usually doesn't get much warmer than 95 F .. maybe 100F at most... with humidity... So on a cool day I'll try to shoot for 185 F aswell... My t-stat is 180.. and I definetely will go with that guage... I lke the pillar guage's ... haven't added any extra gauges yet.. but I'm sure I will add more one day.. I still have a old 2 row rad.... is there a good place to mount my old temp sensor for the old gauge if I want it to work.. I want to put the new mechanical gauge in the spot where the old one was.. and the spal control unit can be hooked up to the same sensor as the mechanical gauge apparently.... I can't seem to locate the other spots for sensors... kinda seem burried under the intake.... is there a thermostat housing that comes with the hole for a sensor... I can't seem to find one... and to be sitting at 185 any ideas about where I should start with... with the low.. high settings... or I guess I can just play with it.... 160 low 200 high seems crazy if I never hit 200.... maybe 160 low 170 high.... just a guess. should I be mounting a sensor on the rad somewhere instead of going on the same spot as the gauge??? that way I'd be measuring the coolant before that is going into the engine... ????

oh and will that guage fit in one of those pillar gauge units.. or is the size wrong...

 

[Sicarius428]

Autozone sells a pretapped tstat housing for 10ish dollars that is cast iron. I bought it and used it for a little while but I ended up giving it to a friend and tapping my stock AL one. I believe you need to use a 3/8 NPT(pipe thread) tap. The most ideal spot is the one under the intake. Some intakes have a spot in the rear that will work too but supposidly not as accurate. The one in the tstat housing isn't suppose to be as accurate either but it seems to work for me.
Kevin

 

[HISSIN50]

Kevin covered it well. I used the rear port on the '88 and the parts store housing on the 94.

Your Spal controller will probably tap into the ECT, which is completely different than the stock temp sensor.

If you run a balanced T-stat (Mr Gasket, Bob Shaw, etc), you can set the fan on the lower side. The lowest on/off I'd run is 195/187*F. If you let your fan-off temp get any lower (too close to the rating of the t-stat), there's a chance the fan will run almost constantly.

Good luck.

 

[jrichker]

Alternate placement for a temp gauge sender: Use the heater feed that comes off the intake manifold. Cut the rubber hose that connects the manifold water feed to the heater and splice in a tee adapter for the temp gauge sender. Be sure to use the same water feed line as the ECT sensor. That way you will get the most accurate temp readings.

Tee adapter info:
Make a pilgrimage to your local hardware or home supply center and get some copper pipe and a tee that fits the temp gauge sender. Solder two pieces of copper pipe onto a copper pipe tee with threads in the tee part. Find the correct brass fitting to match the temp sender threads to the tee fitting.

 

[Darkwriter77]

Hmm ... never thought about the tapped water outlet being a spot for a temp sender, but now that you mention it, I do recall seeing those with the included plug for sale while crawling around the back parts room. You wouldn't happen to have the part # off hand for the one with the tapped outlet, wouldja'? I'd like to be able to run both my stocker and the Autometer gauge I've got on my notch; the Autometer one "sticks" a lot of the time and doesn't pop up to read correctly for a minute or two, and the stocker is just laying on top of the intake manifold doing near-nothing.

I swapped out the water temp gauge of my Autometer three-gauge set once with some other brand of temp gauge because that "sticking" gauge thing was starting to annoy the poopie out of me, but the other one did the same exact thing. It'll sit there on 100* for what seems like ages, and then it either hits a bump or the T-stat opens or whatever and it finally decides to come up to read a proper temp; the stock sender builds up a reading gradually at a normal pace, so I dunno which of the two darned things to believe, really.

Just thought I'd throw that out there, in case you decide to plug it into the same location and wind up having the same issue. I dunno if it's a design thing with the gauge (or brand), or a problem with my choice of sending unit location.