engine cooling

[bigjeep1980]

just wondering what my temp should be at hiway speeds when it`s about 95 out, 80 cj7, 304, big 2 core aluminum radiator, flex a lite electric fan 3000 cfm, aluminum koolerflow water pump, at about 2800 rpm 63-64 mph. auto tranny has it`s own cooler, so does the oil, 160 degree thermostat, running about 215-220, runs about 175-180 at low speeds. 4.10 gears 33x12.50 tires :-|

[Mudrat]

180-190 sounds about right - if your radiator is clear. Under 200 is good at slow speeds. But get some mud/sand impacted in there and the temps will blow the rad-cap spring to the over-full bucket quickly.

[Goose]

It is possible that you are actually moving the water too fast through the radiator. you may need a restrictor under the thermostat.. What happens is the water goes through the rad so fast it cant transfer out the heat it picked up in the block..thus the lower temp at slower rpms.


(See See I AM a theoretical genius!)

[AMX69PHATTY]

I believe it may actually run cooler at highway speeds with a higher temperature rated thermostat since it will actually keep the water in the radiator longer as Goose mentioned, even without a restrictor.

In drag race cars which run no thermosat, the use only a restirctor just for this reason and they are available in a variety of sizes so they can be "tuned".

Maybe try a 185 degree thermostat since that's the temperature you're seeing at low speeds already, and see how it does at highway speeds.