Fellows, I could use some hints on this. 56' f100 272 stock with proper rad. (used but appears clear enough), new 180 deg. thermo., new proper hoses and rad. shroud. Mech. gauge mounted in dr. side bank of head with adapters and 50/50 mix of new anti-freeze. Can drive all day with no issues except uncomfortable feeling the temp. gauge never reaches 180 ish. I drove with the rad. mostly shielded with temp rising to 160 deg.. A total of 10/15 deg. increase after shield. I'm stumped any ideas? Phil

 

Where exactly is the temp gauge located at- front, or back of the engine?

I guess it could be a possibility that the head gaskets are installed wrong & the coolant is entering the front of the block & immediately going into the front of the heads & back to the radiator (never really circulating to the back of the engine). Fords of various engine families are prone to this because of the confusing head gasket installation/markings. If the gauge is in the front, it will read cool, but a gauge in back would show the high temps.

Normally if this is the case, though, the engine will overheat fairly soon. I'm confused a little (nothin' new for me!) by your post title. Are you saying A) the engine seems like it's overheating but the gauge reads low temps, or B) the engine seems just fine, but the low gauge reading is bothering you & you don't really believe it? I'm guessin' B.

Mech. gauges are usually goof-proof to install, as long as the tubing isn't kinked, as opposed to electrics. Is is possible to verify the temp with another gauge? PITA, I know. You could also try leaving the rad. cap off & using a meat thermometer, though it isn't super accurate.

FWIW, mine runs under 180 & never got past 190 or so even driving at uhh, 65 during 95+ degree days on the Interstate.

Maybe Cap'n. Johnny will add more insight to this as he is a professional radiator man.

 

The meat thermo can be easily calibrated. Put it in boiling water, look up the temp of boiling water at your altitude, and adjust accordingly.
After doing the check with thermo, I found my elect gauge was reading something like 15 degrees high. Replaced it with a cheapo Sunpro elect gauge and the gauge was about 15 degrees low. Finally put in an Autometer elect. gauge and the temp reading was dead accurate, measured by meat thermo and verified by Pyrometer. Truck almost always is at 160 degrees, unless idling. My 4 row radiator is just too big. Thermostat is a quality brass 180 degree unit.

 

Why, oh why must you always bring scientific methodology into my intentionally vague shadetree mechanic methods??

Actually, I can't seem to find a decent thermo anywhere, right now. Went to replace our faithful old Taylor, deceased before its time by one of the kids, & can only find made in China crap, where the needle rubs on the glass. Must need to go to a higher class of establishment than Wal-Mart.

BTW, Mike, did that Stewart t-stat work out OK, or did you use something else?

 

I think it works fine. Couldnt say for sure unless I could see it under glass . The big radiator, added to every aluminum motor part made for the Y, plus remote filter, no hood and light truck of 2640 lbs, seems to destine me to run cold. Could still block off radiator, but I'm letting bugs accumulate there and hope they will have the same effect. In the meantime, I change oil every 500 miles, and the little 2100 carb acts like a governor on rpms. The temp hopefully will jump up 10 degrees when the hood is added on.
Maybe my low compression ratio doesnt build up as much heat as it would normally, too?

Cuzin, sorry about the diversion. This is your thread.

Mike

 

I'll thank for the responses to my situation and I enjoy the banter also, no toes stepped on here. I'll have to do some research on the head gasket thing, the new summit temp. unit is in the back. I guess my concern is that the water never makes a loop cause of the thermo. not opening which isn't by design. Should I drop down to a 160 deg. thermo instead? Side thought which may only confuse things is that I thing the eng. is a 272 however the fuel pump I replaced is from a 239. Can the timing cover cross fit between a 239 and a 272? Block letters state a 272 if I recall. Hence maybe a screw up when the rebuilt was done........by a shop from way-back-when (tag on eng.) This whole thing started with a simple gauge installation since factory one was defunk. Phil