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Quick question...what would be the normal operating temps for a 400 in a '78 F100. Yesterday, on a 73 degree day, I was running around 200-210 after warming up and driving about 25 miles at 45-55 mph...Thanks, Rick
My 400 is bored 60 over and it runs about 165 no matter if I stand on it or drive it normal. I've changed temp guages twice a thermostats a few times. I run a stickshift and a good size radiator. now that i've probaly bored you with my facts 200 to 210 is ok but i've always more comfortable with about 195
The operating temp of your engine is set by the operating temp of your thermostate installed. The temps you have is normal for thermostate that is designed for 190 to 200 degrees. You can regulate it lower with a different thermostate. I run a 180 thermostate in my truck as I live in Alaska nad need the heat in the winter.
Hope this helps.
BJ 77 F150 4x4 400/C6
Rick, I have a 195 deg stat 390FE 1972 I see 200/205 on New VDO gauge(first warm up). Then when it Opens it drops to 175/180 (in rush of cold coolant from radiator. After that it settles in at 195/200. I have tried to use a 180 deg and was not happy. too many cold engine problems.
It seems that some later model systems have to see 195 to work properly. Too many things are Temp related in the smog/vacuum systems. Using a lower temp thermostat only compounds the problem.