Topic: NO thermostat? why?

[sanluis09]

Hi,

I want to know your opinions in regards to discovering a low mileage unrestored 1965 289 Mustang with no thermostat.

Is there any good reason for not installing it?

Thanks
Luis

[midlife]

None for street driven cars.  I suspect drag racers don't use thermostats.

[RoyceP]

Thermostats tend to eventually not work over time. Yours would have been pretty old had the original still been in place. Likely discarded by someone with no money trying to keep the car on the road with a bad radiator or water pump.

Hi,

I want to know your opinions in regards to discovering a low mileage unrestored 1965 289 Mustang with no thermostat.

Is there any good reason for not installing it?

Thanks
Luis

[jwc66k]

Thermostats were originally intended to be used to get an engine up to operating temperature quickly by being closed, then slowly opening at a designated operating temperature. Back in the 50s and 60s, it was common in warmer areas (the American South West as an example) to remove them under the assumption that the hot flowing engine water would be cooled better without the thermostat's "restriction". That thought is sort of true, but in the real world, doesn't work. There are other flow restrictions, in the pump, manifolds, etc, that have the same effect as the thermostat's slow flow. You can run a car without one, but it usually does not make that much of a difference - except psychologically.
Luis. Do you have relatives in the Denver area?
Jim

[midlife]

My take on thermostats are that they set the floor for operating temperature of the water, in addition to helping the engine reach operating temperature quickly.  Ford recommended 198* thermostats, but those are usually hard to find.  Most folks use 180*, but some use 160*.  Low temperatures are believed to be harmful to engine life, and some believe it can cause oil sludge.

[jwc66k]

Low temperatures are believed to be harmful to engine life, and some believe it can cause oil sludge.

Oil sludge is more common in cars that the owners neglect proper maintenance.
Jim

[Murf]

Keep in mind that the primary function of a thermostat is to limit how COLD an engine runs.  It was never intended to limit how hot an engine could get.  In some cases lack of a thermostat will cause overheating by letting the coolant flow too quickly through the engine and not allowed to "soak up" the heat the  liquid is intended to transfer to the radiator.  Many have discovered that a small block ford is one of the engines that in most cases will run hotter with NO thermostat.  There is little or no practical reason to remove the thermostat from a street engine!

[Bob Gaines]

Keep in mind that the primary function of a thermostat is to limit how COLD an engine runs.  It was never intended to limit how hot an engine could get.  In some cases lack of a thermostat will cause overheating by letting the coolant flow too quickly through the engine and not allowed to "soak up" the heat the  liquid is intended to transfer to the radiator.  Many have discovered that a small block ford is one of the engines that in most cases will run hotter with NO thermostat.  There is little or no practical reason to remove the thermostat from a street engine!

To add- Many track cars run restrictor plates instead of a thermostat . They are typically adjustable in some way . They are used to dial in the most optimum cooling of the water by limiting the flow to the best amount as it passes through the radiator so as to allow it to do it's job.