Venom351R said:
Lee12609 said:
you MUST run a thermostat or a restrictor plate atleast.
without a thermostat the car will run cool for a short period of time, but the coolant wont stay in the radiator long enough to cool after so long it only gets hotter and hotter. i know this because i just tried it last week on my car. it was fine for 15-20 minutes of cruising, then it started to creep up and up and up. installed a NEW 165? thermostat and all is good. i should say that my car is a 96, is boosted, and tuned to turn the fans on at a lower temperature... just so nobody says "that thermostat isnt doing any good"....
It may be tuned for the fans to kick on at a lower temp but the engine is still not operating at an optimal temp. Heat is not always a bad thign its just when there is to much of it but the engine is meant to run between 180-210. Below that the system is always going to be in open loop always trying to cool it down.
optimal temp for what, engine wear, power, or fuel economy? realize, this is an iron block aluminum headed 4.6 @ 10psi non intercooled.
with a 205 degree thermostat the car easily runs 215 degree, too hot for comfort with me, might be best for engine wear, but not for power or ET, MPG isnt effected because after 130 degrees or so its closed loop... also realize that at that high of a coolant temperature my transmission fluid temperature is also that much higher.
with the 165 degree thermostat i never see over 185 degrees which keeps the transmission fluid cooler, the ET's lower, and the timing curve safer, its a no brainer, but ONLY if you can tune to change the fan temperature. no point in opening the thermostat if the fan doesnt turn on or the water in the radiator wont get cooled (while sitting), so the coolant will still heat to the same temperature regardless of thermostat.
