Engine Temperature - what is best?


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By jrw429 - 13 Years Ago
What is the "best" temperature for an engine to operate at? In my case, a 292 that seems to be a little tired, and is never pushed for hard acceleration. But it does do a lot of interstate miles, usually 65-70 MPH.



What is the "correct" way to measure the temperature. I have the dash gauge, but should I trust that? Am I better off also measuring another way?



Are some thermostats better than others? What temperature rating should I get for the thermostat?



I don't think I've seen a fan shroud for a 57, or any other Y-block. Are these available? Will it make a difference? What about using an electric fan? Pusher or puller? With or instead of the engine fan?



Summer is coming and I want to be ready! Thanks for all your help.
By PF Arcand - 13 Years Ago
jrw: You don't say if you've actually had trouble? Yes, there are differences in quality of Thermostats. The consences seems to be that Stant is not one of the better makes. It used to be common, particularly in hot climates, to run cold (160o for instance) thermostates. However, it's generally recommended to run at least 180o ones. Most late model cars run 190o or so ones. It's supposed to be better for quicker warmup & reduced engine wear. I'm sure others will chime in with specific parts recommendations.
By charliemccraney - 13 Years Ago
If it's not boiling over, it's not too hot. When it comes to the coolant, hotter without boiling over is best. Use an infrared thermometer on the thermostat housing.

The Robert Shaw type of thermostat is probably the best. A shroud is not necessarily required but it can help to more accurately control the temperature, particularly at idle, and is generally a good idea.
By Ted - 13 Years Ago

As Charlie mentions, the hotter the better or least to the point that you have no issues with keeping the coolant within the system.  As a general rule, 190°-195°F is the more efficient temperature for the engine to be running at.  Running colder than this puts the engine in a situation where it wears faster and the fuel is not burning as well.  Taking the temperature at the thermostat just before the coolant returns to the radiator is the desired location for temperature readings.  Using the rear block location gives an artificially lower temperature reading and not the actual temperature that’s seen at the entry to the radiator.

By geraldchainsaw - 13 Years Ago
hi Jim,    i belong to another forum,  check it out,  they have lots of answers to things like your heating questions,   i went thru the same thing,  i have a 57 ford also,   57fordsforever.com ,   jerry
By jrw429 - 13 Years Ago
Thanks everyone. I haven't seen any problems with my wagon. My gauge reads consistently at 185. I do lose a little coolant over time but I wouldn't call it boiling over. I'm just challenging what I had always assumed. Now that I know, I can fine tune things. Oh, one more question I forgot to ask: what pressure is "best" for the radiator cap?
By Riz - 13 Years Ago
Mine is a 7psi never had any issues don't know if it is OEM but it works fine.
By GREENBIRD56 - 13 Years Ago
Experienced guys on here have reported more success with low pressure caps than vice-versa. The older radiator tanks simply don't like the higher pressures. That said -mine was reworked by a local guy who has done alot of "desert" radiators and he recommended otherwise.

This little chart shows what happens when you mix up your coolant - and change your cap pressure. Makes it possible to predict the temp where your system will decide to boil. Pressure runs up the boiling temperature and reduces the chance of boilover - but don't put some sort of NASCAR 16 pound cap on there - those are way out of our league and will (immediately or eventually) cause structural leaks to the rad.

Yes - check your temp with an infrared temp device, right on the thermostat housing. I always check the outdoor (shade) ambient at the same time for a comparison, as that shows the inlet air temp to the radiator. The difference is a useful number to know - if your system is running over the thermostat setting. Mine often runs 100° over ambient due to the T-bird radiator being small - and the water pump somewhat less than efficent.

If you don't already have one - find a six blade fan for your outfit. Preferably one of the rigid blade variety as slow road speeds, heavy grades, and raised engine rev's will flatten out a flex fan at just the wrong moment. Speedway in Lincoln sells the rigid fans for a decent price (with steel or aluminum blades) and a 5/8 hole to match most waterpumps in passsenger cars.

Testing has shown that the larger poppet thermostats - the "Robertshaw" type mentioned above - can provide a considerable boost in the gallons per minute that circulate through your radiator. This is a pretty cheap upgrade - if you have one of the little thermostats in there. The small ones have about a 1.0 inch poppet with a lot of sheet metal around them - and the large one you want has a 1.50 inch poppet. My personal preference is to use one rated at 180°F opening temperature.

 

Have a nice summer of crusin'! Cool

By HT32BSX115 - 13 Years Ago
Howdy,





As indicated above, hotter is really "better".



Your only limitation then becomes how much pressure can your radiator handle safely.



I would like to run mine with a 190 or 195 degree stat.



My radiator was re-cored and rebuilt recently, and the rebuilder told me I would probably be safe with a 10 psi cap. (7 psi originally)



I do not know if 195 will exceed 10 PSI but, I'll find out I guess. The large area upper tank on my (now 4-row) radiator could blow out if I operate it at higher pressures.





Cheers,





Rick



EDIT: Ok..... Being the brain-dead engr that I am, I did a little snooping around and looked at some charts on 50:50 ethylene glycol.



According to what I found, operating a 50:50 mix at 200F will produce a vapor pressure of approx 600mm hg.



Or 11.6PSI.



I may try a 12 or 13 PSI cap (if one exists) The radiator guy did tell me that he pressure checked my radiator to 20 PSI but said not to use a 15 PSI cap for normal use.





It'll be an experiment!