Smaller radiator for FE?

[Christ]

Originally Posted by Frank Lee

Interesting point...

but does a prop have comparable properties (pun!!!) to an enclosed impeller pump?

So I just went and got my spare sump pump- axial impeller like a car water pump- put it in the kitchen sink with water and turned it on with my hand over the outlet.

mmmmm... pump motor so powerful it didn't vary much, unlike the hair dryer. I thought it slowed under load ie. pumping water...

Can you vary the input voltage to under-rate the torque?

[Frank Lee]

I don't have anything handy for that.

What I'd like is a tach for that motor.

Edit: What was I thinking? I need an ammeter. Don't have one for AC.

[Christ]

Got a high speed camera? It's a slow, tedious way, but you can gauge max RPM with a high speed camera.

[Frank Lee]

Some water pump stuff:

Inside BMW's Latest Powertrain Technologies

Water Pump Tech

OK here, from a piece regarding sensors for centrifugal water pumps:

Alternately, low load sensors can detect:• Minimum flow• Dead-heading• Flow restriction (i.e., plugged discharge filter or strainer,clogged spray nozzles, closed discharge valve, etc

http://www.warrender.com/upload/prod...28dab2a7fd.pdf.

So me thinks automobile water pumps could cavitate just like that hair dryer and not like that boat, were flow to be stopped.

But then... the flow isn't ever stopped even when the stat is closed. Circulation is constant through head and block.

Now I think whether t-stat is open or closed likely has very small effect on pump load- too small to matter. For what my opinion on that is worth.

And:

In centrifugal pumping applications with no static lift, power requirements vary, as the cube of the pump speed and small decreases in speed or flow rate can significantly reduce energy use. For example, reducing the speed (flow rate) by 20% can lower input power requirements by approximately 50%.

http://www1.eere.energy.gov/industry...pdfs/38949.pdf

Combine that with the SuperChevy dyno stuff, and underdriving the water pump can save HP but don't do it at the expense of low rpm cooling. And they didn't even bother reporting testing below 3000 rpm cuz it was too small.

[chuckm]

Just to investigate, I did find that the ECHO does have a smaller radiator (it has the 1.5L engine). As you would expect, the mounts are different and the hoses are in different locations (same diameter heater hose ports though). They both have 5/8" diameter radiator tubing, so the difference in pressure drop will only be due to the shorter tube length. Difference in core size?
Corolla: ~340 sqin
ECHO: ~260 sqin
Or about 25% less area. The height is the same, making the mounting a bit simpler. At a guess, coolant volume would drop by ~10-20%.

EDIT: I'm diggin' what BMW is doing on their water pump tech.

[wagonman76]

Originally Posted by RobertSmalls

And here I was thinking about trying to get a larger radiator in the Insight. Yes, it's got more thermal mass, and that's bad, but if you had a larger radiator, would that allow a smaller grille opening?

I suppose what I want is a carefully designed radiator, don't care what size, where a small amount of air entering the engine room provides as much cooling as possible. Maybe a compact, three row radiator behind a small grille opening would work.

The Insight has the exhaust manifold integrated into the head for better exhaust heat retention and faster warmup. The downside of that, I'd imagine, is the need for more airflow across the radiator once the car is warm.

That was my thoughts too. I have a HD cooling system in my cars and blocking the grille is negligible to engine temp. I have to wonder if the light duty system would require me to remove the grille block sometimes.