I'm not disagreeing with you Bob, but I've never known of anyone having cooling issues with a big block Mopar. Maybe I didn't know some were using Flowkooler water pumps? I have known of many folks who have had trouble with cooling systems on 400c.i. small block Chevys' due to the larger bore in a small block casting. Anyway, the Flowkooler looks like a great product.
As it's been said many times: "Don't knock it until you try it"....SB Chevy 400 engines used Siamesed center bores cylinders, aggravating uniform cylinder cooling. Remember....high gallons/minute and velocity flow rate is the secret to efficient heat transfer and cooling......
Yes there should be a spring in the lower hose for that exact reason.
That's where the issues usually are....idle and/or low speeds. Also the T-stat is supposed to help slow down the flow if everything is working right. Sometimes too fast flow and the coolant goes through that radiator too fast and doesn't have a chance to cool down so a restrictor plate can and sometimes works better. Also, a large enough radiator also helps. Used to be lots thought a 4 row radiator was better but it's not.....better off with a radiator that's just as thick as a 4 row but only has 2 rows.
I agree with your comment on 4 row and even 3 row, they make the tubes so small and then i feel with all those tubes it impedes air flow through the core and they clog quicker.
It's not so much that but surface cooling per tube. 'Tiny' tubes don't do as well as larger tubes do....there's more 'wall' on a larger tube to benefit from the air flowing past them. I actually learned from this on a single row radiator in a Dodge Dakota pickup and then researched it.
Sorry.....incorrect PREMISE.....FAST flow can exchange more heat per unit of time (BTUs/hr/gallon). While you state the coolant should move slow thru the radiator to give up the heat, what about the coolant that remains in the bock and heads gaining heat. Since there is only one circulation pump, (a fixed impeller centrifugal design), rotating at variable RPM's, it's volume and velocity and the pumped coolant, the worst case is low speed. The basic idea is to maintain the highest temperature difference between the coolant in the radiator and the air temperature passing through the radiator. This can be done by circulating the coolant as fast as possible (within physical and practical limitations). The thermodynamic principle is:
Too slow moving....? Yes, that's not good either but too fast isn't either....been there done that. Lots of variables in a 'factory' cooling system and mainly in the block and heads of this 50+ year old stuff. What usually happens is lots of experimentation in the system that someone has.
YEP!
Good stuff Bob! I have a question for you as seem to be very knowledgeable regarding thermodynamics. Wouldn't a big block Mopar engine run a bit cooler if only the cast iron heads, and the cast iron water pump housing were replaced with aluminum components being aluminum dissipates heat at a faster rate?
