[quote=moparx]those "flow kooler" water pumps are the ones with the "circular" vanes about 1/4" or so high, on a cast circle base ?
i always like to overdrive the pump some, but is there such a thing as being overdriven too much ? there are only so many pulleys to choose from.
The thermostat serves another purpose, and that is to regulate the flow rate. Removing it will cause overheating but can help compensate for a crudded up radiator.
Pushing the coolant through a good radiator too fast can also cause O/ heating as the coolant may not have enough time to exchange the heat. So I would say yes. remember you are dealing with several variables. Flow rate, pressure driving the flow, pressure in the system, size of the radiator, air flow through the core, Ambient temps, BTU's being generated, and the the infamous core debate itself. Probably a few others as well but that's a kwik list
Laminar flow can affect both the airflow and coolant.
There is a dwell time required for both the air and coolant to absorb or shed heat.Despite what we observe in the top of a radiator, the coolant in an engine dose not achieve/maintain turbulent flow (exceeds its Reynalds rating) through the entirety of the system (if at all), there are many different flow rates occurring in the different sized passages.
This leaves laminar flow as the predominant effect, with much of the heat moving slowly on the edges and fast moving cold coolant channelling to the centre of flow.
Hence the balancing act of flow rates, volumes, materials in play, size of condensers and so on that every auto manufacturer has had to do for over a century now.If it were as simple as "make the coolant flow faster", there would be only a few different smaller radiators in use and water pumps would be multistage jobbys flowing many multiples of the volume (and pressures?) in use now.
I use manually controlled heat exchangers on a regular basis and I can assure you if the coolant is too fast, performance can drop to the point of not working at all.
No, im not an engineer, just a tinkerer and a thinkerer
There is a HUGE issue with your thinking regarding how much time the coolant stays in the radiator. Thinking and saying the coolant has to
stay longer in the radiator to absorb more heat is a circular logic. And a flawed one.
Any and by any I mean ANY restriction in the flow of coolant (or air) degrades the cooling systems ability to do its job. That’s a simple fact. Look in the Factory Service Manuals for different years of engines and you will see the performance engines had OVERdriven water pumps. Not UNDERdriven. UNDERdriven might work in a low performance application but where coolant temps are critical (this could be for any number of reasons but a couple would be making more horsepower requires more cooling and running higher compression on limited octane fuel such as pump gas requires engine temperature to be controlled and as such in my 11.77:1 pump gas engine I keep the coolant temp at 160 to control detonation) you overdrive the pump.
Under driving the pump was a 1990’s fad that should have died with the 90’s.
So while you are tinkering and thinkering, consider this. Every time you leave the coolant in the radiator longer, the coolant stays longer in the block. Where it picks up more temperature and that means you start taxing the cooling system harder.
An air to water cooler (thats what a radiator is) is limited in its ability to cool by whatever the ambient temperature is. That’s one reason a thermostat is needed, even though it’s a restriction. You have to set the MINIMUM coolant temperature with it so that on days where ambient temperatures are low you can get the required minimum temperature you need. For me, that’s 160 or the heater becomes less effective. And I’ve driven my junk in near zero weather.
Along those lines, let’s take a look at a 100 degree day and think it through. In this case, the lowest possible coolant temperature you can attain is 100 degrees. Of course, that doesn’t happen because you have a thermostat to regulate minimum temperatures AND because as the delta T decreases (thats the difference between ambient and coolant temperature) the ability of the coolant to drop the temperature becomes less effective.
In other words, let’s say you have a 190 degree thermostat and it’s 100 degrees ambient. You have a 90 degree difference. If we have an ambient temperature of say 60 degrees you’d have a 130 degree difference. That change in temperature differential between those two ambients means the lower ambient temperature has more cooling capability than the higher ambient. And those numbers are taking for granted the cooling system is good enough to maintain thermostat temperature on a 100 degree day. Most cooling systems aren’t well thought out enough to do that so you may be at 195 or even 200 degrees of engine temperature and that makes it even less efficient.
All this matters because the longer the coolant stays in the radiator the longer it stays in the block, picking up heat. If you have enough coolant flow that when the coolant temperature is at your thermostat rating, then it’s easier to keep the coolant at that temperature. But, if you don’t have enough coolant (and/or air) flow, the n forcing the coolant to stay in the block longer taxes the system harder.
You need the coolant speed to make the coolant take on as much heat as it can to reduce hot spots and to cause turbulence. Laminar flow (air there really is such a thing in a cooling system) might sound good on paper but it’s not.
When you see a cooling system that can’t maintain its thermostat rating you KNOW that the coolant is moving too slow thereby staying in the block too long, or you don’t have enough airflow or both.
It’s time to slay the wives tale that keeping coolant in the radiator longer is the correct way to do it. It’s not. It’s bad.
