Re: Change of radiator core affecting cooling performance in 1949, 23rd series

Posted by Joe D'Agostino On 2017/7/7 15:53:46

Yes, there is an issue with the larger core. I am having problems with high engine temperature at idle but not at cruising speeds.

I have researched it and realize that now that I have more volume in the radiator, the fluid runs through it more slowly.

It is like a hose, if you pinch the end of it, the flow will go faster but if you open it up it will flow more slowly. And cooling is not as good at lower flow rates.

The cooling at low rpm's is not as good as it used to be when I had the standard core. And the spread between cooling performance at low rpm's and cruising speeds is much different than it used to be.

The radiator shop agrees that the fluid is running through the radiator slower but also tells me that since the radiator is larger, the coolant stays in the radiator longer so it should be cooling better. The problem with this reasoning is that you now need more airflow from the fan at lower rpms to make up for the slower fluid flow rate. (This fact about needing more air when you enlarge the radiator is well publicized on radiator performance sites). ButI am not interested in adding an auxiliary fan to the radiator.

I have had the engine rebuilt, added new water distribution tube, new water pump, 140 degree thermostat and all channels for the cooling redone. Everything is clean.

I even made sure that I always use a Ganno filter in the upper radiator hose to make sure no engine crud clogs the radiator. (I had this filter in place before the rebuild but still have it left in today).

So I wish to get back to the original core to improve the cooling at idle.

That is why I want the original specs for the original core.