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Understanding the range of thermostats and applications for emission, vacuum valves opening etc..
What is the ideal temperature for a thermostat not having to deal with emissions..?
my 79 L82 w ac as many others is 195f for lots of reasons emissions as well.. but i noted the large range for previous years, assuming performance and longevity of oils etc..was the priority..
I went with 180f as that is what i always remember when younger..
I am wondering now for a spirited all season driver, would it make sense to go even lower?? they even had 160f?? or maybe 170f to 74? Given the heat in the engine bay i could only think lower would be better but at what risk? if any with what cutoff?
I thought 180 was the sweet spot. I'll say that my 180 degree high-flow Milodon thermostat, with a tiny hole in it to prevent air bubbles, will range from 160 on the highway, to 193 in stop and go traffic (the fan-ON temp). This is from a two-wire sensor that I added with a digital readout.
Somewhere on this Forum I'd read that 160 was too cold. FWIW, NASCAR runs way hotter, for aero reasons*, mostly.
*Speaking of aero, my stock 80 was redesigned by GM for better aero, and has lots of flow through the radiator. More, now, with no AC and an open engine compartment. YMMV with your 79. I also have a 79 that needs electric fans this winter. If you can suggest a meaningful experiment, I'm happy to take some data.
Since your car does not have an ECM, install a 180*F thermostat in it. The thermostat does NOT set high temperature for the engine; it sets the minimum temperature for the engine...so that it will warm up quickly and not run too cool. Depending on the capabilities of the cooling system in your car (radiator, water pump, etc) the engine may run warmer than the thermostat rating. If it runs significantly hotter than 180*F with that stat, you need to deal with other components to solve a hi-temp issue.
Agreed, 180 is the sweet spot. I run a high flow water pump and a high flow thermostat. 180.
To low and you can and likely will develop moisture from condensation that will not get heated off especially on shorter runs. To cold is not good.
I agree with everybody, and bikespace. 180' with a 1/8 hole drilled in the flange to bleed out the air. It's worked well here and it can get fairly hot.
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IT depends on how hot it gets where you are. In the summer when its 90 degrees and above 90 percent humidity I run a 160* and it was running about 180 all summer long. This fall I put in a 180* so I would have some heat and its stays in the same temp range.
Thanks all..
i am really wondering what is the ideal temperature as low as you can without issues like needing to keep oil right and wear etc..
i have zero issues summer or winter with dewitts rad and factory fan maintaining 180f.
just thinking if 160 or 170 was ok pre emissions, and the less than ideal situation with heat mitigation…10-20 degrees can only help?
of course i would assume there is a floor somewhere that is adverse to engine?
Thanks all..
i am really wondering what is the ideal temperature as low as you can without issues like needing to keep oil right and wear etc..
i have zero issues summer or winter with dewitts rad and factory fan maintaining 180f.
just thinking if 160 or 170 was ok pre emissions, and the less than ideal situation with heat mitigation…10-20 degrees can only help?
of course i would assume there is a floor somewhere that is adverse to engine?
A quick search returned a bunch of folks who were nearly overheating, not your problem. I found one random forum reply related to a lower bound on temp (not this Forum, but the username checks out). The OP he was replying to had a 180*F thermostat.
Originally Posted by grumpyvette
If performance is the goal leave the temp where it is currently and jet the carb to run a 12.7-12.8:1 fuel/air ratio , as long as the oil temps occasionally hit 215F to boil off any moisture trapped in the oil and prevent acids forming youll be fine.
So perhaps some more internet research related to oil temp? Fortunately, I just picked up an 81-82 center gauge cluster with an oil temp gauge, so I'll be adding that this winter.
EDIT: @grumpyvette is also a member of this Forum.
A quick search returned a bunch of folks who were nearly overheating, not your problem. I found one random forum reply related to a lower bound on temp (not this Forum, but the username checks out). The OP he was replying to had a 180*F thermostat.
So perhaps some more internet research related to oil temp? Fortunately, I just picked up an 81-82 center gauge cluster with an oil temp gauge, so I'll be adding that this winter.
EDIT: @grumpyvette is also a member of this Forum.
perfect summary…
i have been searching and have heard the moisture point before..I’m also wondering if synthetic changes the concern as well..i run the zinc mobil 1 15x50.
it just seems to me that if GM put in 160° thermostats it could not hurt engine integrity. I can only assume that the temperatures came up for emissions purposes.
Seems like low hanging fruit on heat mitigation with these cars, and plenty to run my heater..
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If you aren't worried about emissions, use a 180* ts. Also, synthetic oil. I read a technical paper years ago about the effect on engine wear with respect to oil temperature. I don't recall the testing method but the conclusion was a 180* ts provides the optimum oil temperature i.e. best lubricity - not too hot nor too cold. Now if you don't put on a lot of miles in a year, a 160* ts shouldn't be an issue if your rad is capable of cooling the coolant to maintain the normal engine operating temperature at 160*. How much quicker will an engine wear out using a 160* vice a 180*? Probably akin to tire wear difference at a pressure of 32 psi vice 33 psi.
We ran our drag boats on lake water without thermostats or radiators.
The water was picked up off the lake, ran through the engine and you regulated the amount of water going through the exhaust with a spring check valve.
The rest went straight out the transom.
I never had any problems and no loss in hp due to cool water temps.
People dwell to much on weather a 160 or 180 degree thermostat makes any real difference.
thermostat temperature selection
