Radiator Cap

[Jeffrey Engel]

Shannen Durphey <shannen at mcn.net> replied to Tom Cloud:

> > What difference does the rate of flow have to do with heat transfer ??
> > Like I said, seems to me that it's totally irrelevant as long as the
> > liquid stays in contact with the metal -- in fact, seems t'me that the
> > faster the better, since that keeps the delta-T at it's highest !!
> >
> 
> I spent one summer on the pit crew of a roundy-round racecar at our local
> track.  Saw this:  No thermostat, car definitely overheated.  Install restrictor
> plate in water outlet, car ran cool.  Their solution was to pick the right
> diameter restrictor to allow engine to operate at a desired temp on a particular
> day.
> 
> I'll probably get scalded for this one, but I think that removing the t-stat
> actually can allow the water pump to cavitate, and possibly cause a pressure
> difference between hot engine and cool (relatively) radiator which prevents
> coolant from circulating.  While it may seem like I'm grasping for straws, I've
> seen something like this in my work many times.

I've read the opposite.  The idea was that the water circulated too 
fast.  Apparently slower travelling water swirls and eddys around in 
the radiator, allowing all the water to come into contact with the 
tube surface.  When you remove the thermostat the water travels in a 
more laminar fashion (because of the speed) and only part of the
water contacts the tubing.  Any other ideas?

>  A car comes in with the temp
> gauge on WAAYHOT but there's no pressure in the system.  The coolant level is
> very low, so someone grabs new coolant to add to the system.  They can put in
> one or two quarts before it starts overflowing, and the gauge never drops.
> Engine's hot and running, thermostat's wide open, coolant's at the top of the
> tank. But if you shut the car off, let it cool for an hour or so, restart it,
> and immediately reach for the bucket of coolant, you can add a bunch and the car
> never overheats.
> 
> 
> > At this point, I pronounce the ads by the rad makers "HOKUM".  Now,
> > someone prove me the idiot that most have long suspected  ;-)
> >
> >
> 
> All ads are hokum.  Buy my book to find out why :-]
> 
> > Tom Cloud
> >
> >    Warning, dates in calendar are closer than they appear !
 
je
jengel at fastlane.net

     "I can resist anything but temptation"
                                  Mark Twain