I installed an aftermarket SunPro mechanical water temp gauge.I have it tapped into the intake manifold at front opposite the heater hose fitting.I have one of those Mr.Gasket hiflo stats 180 degree.The gauge is only showing about 155 fully warmed up.If I take a heat gun and warm the sender the gauge moves right up as long as heat is applied.The  factory dash gauge which has the sender screwed into head is showing about halfway between "öff" and midpoint of gauge which I think is pretty accurate.Is the water temp 25 degrees cooler at the point I have the sender screwed in or is it more likely the gauge is not correct?Should the water temp not match the opening temp of the stat which is 180?

  

The coolant should be hottest at that point on the engine. Sunpro, if I'm not mistaken, is the cheaper brand that the local auto parts store carries - made in China - so I would not be surprised if it's not accurate. I have one and it's not accurate. It's good enough to tell if you're getting into trouble, though. They do seem to be consistent in their quality. It's the second I have had and the read the same.

Get a hold of an infrared thermometer and see what that says. If the stat really is opening at 180, then the coolant must be 180 or higher.


Lawrenceville, GA

I think you are saying, a capillary bulb-type mechanical temp gauge is not consistant with an electric sending unit/dash gauge, right?  I also read, the capillary-type has real numbers, wheereas the OEM has hash marks.

The capillary bulb has alcohol in it, which deflects a gauge movement.  I have replaced broken tubes on OLD vintage gauges by buying a new (cheap oriental gauge), and soldering the bulb and tube onto a vintage gauge head. (There's more to it than just this.)  When done, the needle needs to be adjusted for accuracy.  After that, you can't beat a capillary gauge.  It is right on the money as long as alcohol is contained.  That's why it usually has real numbers on the gauge that can be checked against another thermometer (like a cookie thermometer which displays real numbers, too).

Electric gauges are good for ballpark readings (that's why OEM gauges don't show numbers).  Connectors can corrode or come loose, showing false readings.

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

No - the thermostat will not hold water at a certain temperature. It only opens at the stated temperature. The actual engine temperature can go up much further than the the stated thermostat temp.



The only true way to see which one is more accurate is to get one of these infra red temperature things and check the temp at both spots where the senders are - the back of the head and where you have the other sender. Ford gauges are known for their inaccuracy.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Thanks Paul.

What I meant to say is that the temperature should be at least 180 with the stat being used.Thanks for clarifying that.I think the mechanical gauge is innaccurate.Once again I get the quality that I paid for.Anyone have any good suggestions for a brand of reasonably priced gauges that work?Thanks

  

  Water temp at the stat CAUSES your thermostat to react.

Cars in the midwest winter, depend on thermostats to keep the engine warm. They close under the predetermined temp, and open at or above same.  Yes, they DO REGULATE your engine's temperature up to the point when your radiator can't deliver enough cool liquid.  The balance is between the heat producer (your engine), your heat exchanger (radiator), and the coolant between them.  If you choke off the radiator's air or coolant, your engine will overheat.

Look, standard thermostats (not yours) have an opening of about 1".  That's fine for most family cars in the midwest and Canada.  Hi volume stats (yours) can flow much more water when temperatures call for it (driving in the hot dessert, climbing the Rocky Mts., etc.).  If it happens your cooling system doesn't work efficiently (clogged cores, low water, no airflow thru the radiator, heat riser is stuck shut, radiator cap doesn't hold pressure.) the very first place to check is coolant flow.  A large-opening stat will allow more coolant to flow when the engine temp exceeds stat opening temp.  Hoses are 1-1/2" dia.  Does it make sense to run with a 1" thermostat?

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

Maybe the Chinese forgot to add the 32 degrees when converting from C  to F   !!!

POP

POP

I have a manual stewert warner gauge mounted in the intake manifold and an electric gauge mounted in the rear of the head and have noted that the manual gauge gives instant info while the electric gauge gives a delayed response.I have also noted that the front of the engine seems to be cooler than the rear of the engine at times,in other words the rear heats up more that the front,but while running for extended periods of time they seem to equal out.The electric gauges are classic industry with a haywire harness so it is quality stuff and i beleive to be pretty accurate.Also if you get a chance june issue of street rodder mag has indepth articles dealing with overheating problem that is very well written and deals with almost every problem you may encounter

I have personal experience with a Sunpro elect. water temp gauge.  Wasnt good.  It showed 15-20 degrees hotter than actual, with infra-red thermo. shot right at sender.  New sender and guage.  Junk.

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

I had a chat with the parts guy at my local supplier."Sunpro isn't what they used to be".I have ordered a different brand gauge which they have sold many with no compaints so we will see how that works.I have all three Sunpro gauges-temp,oil pressure, and ammeter.Going to replace all one at a time as I find better at an affordable price.very true-price is an indication of quality!