"Ashton Crusher" > wrote in message ...
> On Tue, 13 May 2014 15:15:49 -0800, "Guv Bob"
> > wrote:
>
> >"MLD" > wrote in message ...
> >>
> >> > wrote in message
> >> ...
> >> > On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
> >> > > wrote:
> >> >
> >> >>On Apr 21, 6:11 pm, Tony Hwang > wrote:
> >> >>> Ashton Crusher wrote:
> >> >>> > I was thinking of putting a higher pressure cap on one of my cars to
> >> >>> > increase the factor of safety against boiling. Looking thru the web
> >> >>> > for info on the likelihood of changing from 7 psi to 13 psi causing
> >> >>> > leaks I found little on that issue but did find a couple references to
> >> >>> > the pressures created by the water pump. One site boasts of a 19 PSI,
> >> >>> > $25 cap to get you thru your "hard driving".
> >> >>> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
> >> >>> > Thought I'd see if anyone else has heard of this. The claim was that
> >> >>> > the water pump could create over 30 PSI of pressure. Since that is
> >> >>> > double the normal operating pressure of most modern cars I find it
> >> >>> > hard to believe. If the system was at full 15 psi of pressure while
> >> >>> > the car is idling and then your floored it and ran it up to near
> >> >>> > redline and created another 30psi of additional pump pressure, or
> >> >>> > even 10 psi of additioingnal pressure downstream at the radiator cap,
> >> >>> > you
> >> >>> > would immediately cause the system to have to vent to the overflow to
> >> >>> > relieve this higher pressure. I've never seen a car vent due to me
> >> >>> > revving the engine up while I'm working on it. Thoughts?????
> >> >>>
> >> >>> Hi.
> >> >>> There is a over flow bottle for coolant/anti-freeze. Ever
> >> >>> cleaned/flushed your rad. and maintain proper level of
> >> >>> coolant/anti-freeze in your rad.? If the car is old, messing with cap
> >> >>> can spring
> >> >>> a leak.- Hide quoted text -
> >> >>>
> >> >>> - Show quoted text -
> >> >>
> >> >>AMEN!
> >> > A water pump cannot produce system pressure because it just moves
> >> > water from one side of the pump to the other. Expansion due to heat is
> >> > what builds pressure..
> >>
> >> I guess you need to know how a centrifugal pump works. Pressure rise
> >> across the pump is function of the square of its speed. Double the pump
> >> speed and the delta P across the pump increases 4X. Expansion due to heat
> >> will increase system pressure if it is in a closed system. If a fluid can
> >> expand without being constrained---no significant change in pressure.
> >> MLD
> >
> >MLD, do you know where to find a flow rate vs RPM curve for any common stock water pumps? I'm surprised I can't seem to find anything mfr spec curves at the various mfrs and parts houses. Doesn't matter what mfr or vehicle -- just any common street car single head pump.
> >
>
> I was looking to see what I could find on water pumps and didn't find
> much. I did come across this
> http://teae.org/cooling-the-tiger/
> which is pretty interesting though. A bunch of home experiments
> looking at what things make for better cooling.
Thanks, that's very interesting info. I'm not familiar with the particular car they are doing the testing with, but it seems odd to me that they consider coolant temps below 212 deg F as normal. They must be water with no glycol in a system open to atmosphere. However, I didn't read it that closely thought so (as most people say) I may be off.