Check for Purchase

[Roadster Rich]

Along the lines of Mitch's post, I don't know the answer to this, but so many of us have had problems with cooling and the blocked radiators, I wonder if there could be some good calibrated check of the rate of flow through a radiator. For instance, keep pouring water into the radiator so that it is full (flowing out the overflow tube and top of the radiator won't matter) and then disconnect the hose at the bottom of the radiator beyond the drain valve. Then check for the time it takes to fill a 5 gallon bucket or some size smaller that could be put at the end of the side pans. Obviously the drain is not a way since this will be a lower evacuation rate than an open radiator flow, but it sure would be nice to have some method to calibrate if your radiator is plugged and how much. A good engineer might be able to know the proper water pump flow and maybe the drain rate would have to be that at a minimum.

[Mitch]

Rich that's a tough check as the fill and drop method your asking about is a poor indicator if not an all out myth. Your best bet is to check the temp with a meat thermometer and or use a thermal imager (Not just a ray gun) to determine if your running hotter than normal. Timing and fin detachment for heat dissipation are other contributors to running hot. There are misleading and humorous u-tube videos out there by so called experts that show the fill and drop test, don't believe everything you see.
The bottom line is if you want to see if your blocked take the tanks off and physically check each tube or just buy a quality reproduction radiator. I'm not one to fool around with running an engine hotter than it should be on a 87 year old easy to replace part. Shit only last so long

my 5 cents


Here is a quote from Marcos website regarding this::::

"""Don't be fooled by flow testing! Flow testing your radiator as suggested in several publications will only confirm EXTREME problems. You can block more than 1/3 of the cooling tubes on an original radiator and pass the flow test. The reason for this is the lower water outlet of the radiator is the restrictor. It is designed to limit the speed the water travels through the tubes. More time in the tubes equals cooler water."""

[George Miller]

My experience with the old two row replacement radiators is your car is going to run hot on hot days if you run it hard. Best to buy the best radiator if you plan on driving it in hot weather.
As far as timing the water flow out the bottom of the radiator it means very little.
On my 1928 Sport Coupe it had over 25,000 miles on it after restoration. I always used antifreeze in the radiator and drove a lot in 90 degree heat here in NC. Never added water all year long, never got hot. But the radiator was the ten fins per inch, it was the best available at the time.

[dmdeaton]

Great tips on the forum, thanks. This is one for me to list while I am looking for my first A. Check and see what radiator she has. What flavor antifreeze to use in these?

[Mitch]

I run 50/50 which protects against rust and freezing.