Optimum coolant temperature

[valleyguy]

What would be the optimum water temperature reading for a fully warmed up Stude 289
assuming all cooling components are in good condition? or is this of one of those things that falls into the category of "that depends".

Joe D.

[Bud]

I generally consider 180 degrees to be a good operating temperature for Studebaker V8 engines as that temperature allows the engine oil to warm enough to boil off contaminents. I've used 180 degree thermostats in all of my V8's for many years with good results. Many people like to use a 160 degree thermostat as they believe that the lower temperature keeps the engine from overheating which is not true. Bud

[valleyguy]

Thanks Bud, sounds about right but I'm so used to modern cars where the temperature indicator seldom, if ever rises above
the middle of the guage (with no numerical reference), anything above 160 on my Hawk seems "high". Just a
perception I guess. I realize that the thermostat number (eg. 180) only controls the temp at which it opens and won't prevent overheating.
was just looking for a guideline for these engines. Good info, thanks,

Joe D.

[farmhawk]

My 61 Hawk 289 runs faithfully at 180.

[Mark57]

I also...

switched the 160F thermostat in my Transtar with a 289 to a 180F thermostat this past winter and it ran great all summer, the temperature at around the 1/2 way point on the gauge.

[Bud]

A 195 degree thermostat could also be used if the cooling system is in top condition and there is at least a 40% mix of antifreeze and a good pressure cap are used as the coolant boiling point would be raised considerably. The higher operating temperature may even raise the gas mileage a bit. I did that to a 62 Hawk with overdrive with no overheating problems and the gas mileage did come up a bit and as a plus, the heater worked better. Bud

[N8N]

yes, typically the higher temp. your engine is running, without detonation or overheating, gives greatest efficiency. Most late Stude V-8s came with 170F thermostats from the factory, but today you are limited to 160F or 180F. FWIW, 180F is scarily close to 3/4 scale on the stock temp gauge on my '55. (in '55, the stock thermostat was apparently a 160F, they changed to 170F at some point after that.

nate