I can attest to the protection from flying debris reason. On my commute to work one day a car kicked up a piece of steel ... something that flew across two lanes of traffic and hit the lower radiator hose on my 919, bounced off and slid across my left leg, cutting completely though the leg of my riding pants but not into my leg. Upon inspection the coil had been cut almost completely through on three loops but the hose wasn't even touched.
I hope you bought a Lottory ticket that day Rob, because that could have turned out alot worse. Go knock on some wood.
What you describe is certainly possible due to less vaporization of the coolant liquid occuring on the surface of the metal, so, more efficient heat transfer into the coolant, which allows the metal to potentially be cooler.
The statement I made was that the temperature of the metal wouldn't be cooler while the coolant GAUGE reads higher. The gauge reading would remain constant, as it is mostly affected by the thermostat. Of course, this assumes not-extreme conditions...such as racing, really high ambient temps, idling, hillclimbing, and inadequate or undersized cooling systems.
(Also, the gauge reading on "normal" systems is not where you are talking about measuring temperatures.)
Thanks Blackheart, your explanation was much easier to understand than the one I got from the guys at Red Line.
Has-been, were ya'll running Alky? I've seen them come in boiling with frost on the intake!
My vote, protection and expansion.
Yes, methanol. I've never seen frost, but I've seen alot of condensation on the injectors.
On the parts microfiche it's listed as "15: PROTR, RADIATOR HOSE
(LOWER),A AC 1470518-001 $32.58"
I would take "PROTR" to be protector.
That certainly makes sense!
I had a mustang that a buddy of mine and I built I had an issue with the bottom rad hose collapsing. A old school racer instructed me to run a spring thiingy on the hose.... never happened again. Just my experience.
That would be the negative pressure Rob was talking about. I guess the water pump was more efficient at pumping water than the radiator was at flowing it.