Interesting thread. The little 265 sbc in my coupe has been running happily between 130º and 150º on average for the last 20 years or so.
My sbc in my tudor has a 180 stat in it and it ran at 180 for over a year real well. That was with an edelbrock four barrel intake then the same when I went to tripower. Then I swapped to a x1 6 duece log crossram setup, it runs a little over 150 now. I may have missed it, what intake are you running?
another thought... are you running rich by chance? The leaner you run, the hotter it gets. If you're running pretty fat, it just doesn't produce as much heat.
put a piece of card board over 1/2 the radiator, that should warm it up. if it gets to hot cut some of the cardboard off then try again, until you get the right amount, them go make one a preminate one out of metal. Its getto but effective. MrC
My understanding has always ben a engine is a air pump cool air and fuel are denser I drove a cutless with a 355 chevy for 3 years with eather no or a 160 t stat never wnt over 170 and neather me or the guy who bought it has had a problem but thain again mine was also used for street racing and many a triple digit run dow rt 128 but maybe thing are different in newengland
I am agreeing to check the carb and find out if its rich. if it is dead on, maybe take off the shroud or put a bigger pulley on the water pump??? Just thinking outloud
A friend of mine is a older GM tech who was working in the 70 and 80's and is the shop foreman now, he said some of the Chevy vans had problems not heating up. Turns out a small water passage in the headgasket was corroding out to a larger diameter and allowing too much coolant circulation. They would change the head gaskets on them and they would get heat again
You might plug the heater ports if you have them looped with hose. If there is too much bi-pass, it could defeat the thermostat. You could also try restricting the bi-pass and see if that helps.
I run Thermocaps for an accurate reading and a non contact thermometer will give you a better idea of what your engine is actually running at....
weasel, where do you find those caps. i never seen one like that. id like to get a couple of them. i like that idea of knowing the temp in the radiator.
After trying out 3 different fans, 2 water pumps, 4 different shrouds, and 4 different thermostats, i would have given my next check to have had a "runs too cool" problem! My SBC over-heating malady was finally cured after rebuilding the heads!;....valve-sticking issue.
In the race cars we restrict the water flow in the winter to build heat. A few different companys make them, check summit or Jegs for them.
Small block, big alum rad,real fan,correct pulleys, rich mixture, HA! most Hot Rodders are to smart to ever have this kind of a problem!
Rule of thumb is that "the hotter you can get your engine without overheating is the most efficient it will be". I have a 400 SBC & without a thermo the temp was all over the place, i put in a "good" 190o & it stays right there no matter what! JimV
I would try something like that myself, easier to make up something out of a pizza box than to start swapping out probably good parts! Bob