Radiator caps and pressure

[RGSchmitt]

Hi all -

I'd be curious to know the direct source of data that the older Mopar
engines are "designed to run" at a particular (small) range of
temperatures. I note there can be about a 150 F degree variation
(more than 100 C) in US ambient temperatures. Certainly a design
challenge for the Chrysler engineers of the '50s-60s. And to judge
by roadside observations 30+ years ago, not always met.

Bob

[Kevin H]

Originally Posted by RGSchmitt

I note there can be about a 150 F degree variation
(more than 100 C) in US ambient temperatures.

I had to really think about that one Bob, but then I remembered Alaska is a US State.

What's important in the context of this thread is the maximum ambient temp, and even in the US that is always going to be way below the operating temp of the engine. So I guess they design the cooling system to cope with the max ambient and the thermostat regulates the flow of water through the radiator to maintain the intended operating temp of the engine.

The temps I quoted were not operating "ranges" they were approximate normal operating temp for the engines.

The 313/318 temps came from a Bristol 407 owner on this forum, I assumed from experience with his own car. The 383/400 temps came from me, based more upon Setright's notes about the Bristol 411 (the operating temp of my own 411 is not stable!).

If you have more information about the normal (or ideal) operating temps for these engines I would welcome it.