rad and coolant, TPEFI related

[Jim Davies]

On Thu, 23 Oct 1997, John Carroll wrote:

> 
> > From:          "Boucher, Joe C" <joe.c.boucher at lmco.com>
> > Subject:       Re: rad and coolant, TPEFI related
> > To:            "'diy_efi at coulomb.eng.ohio-state.edu'" <diy_efi at coulomb.eng.ohio-state.edu>
> > Reply-to:      diy_efi at coulomb.eng.ohio-state.edu
> 
> > >I tried digging out my old glycol tables so I could be exact, but 
> > >it is necessay  to dry the glycol completely.  You do not want to 
> > >deal with the vapor pressure of a mixture containing water, only the 
> > >glycol.  There will be violent boiling of a mixture at 250 F and 
> > >cooling system pressures.
> > >John Carroll
> > >jac at wavecom.net
> > 
> > ::::::::::::::::::::::::::::::::::::::::::::::::::
> > 
> > There is a company called Mecca Cooling Company.  They sell a propylene
> > glycol based cooling system with 0 pound pressure caps.  The propylene
> > glycol boils at 300 degrees f.  If I remember right the specific heat
> > of  the propylene is lower than water but the delta t makes up for it. 
> > Claims are no hot spots in the combustion chamber so compression of up
> > to 12.5 to 1 is possible on pump gas.  Any water, one tablespoon of
> > superheated water fills a lot of space, is bad, so the overflow line has
> > a desiccant in it.  You have to purge all water from the system.  MECCA
> > claims you can't use Sierra from Pep boys because the additives can't
> > handle 300 degrees, so you have to buy his for $25 a gallon.
> > 
For those who may not be aware, the high temperature, non-pressurized
ethylene glycol concept was thoroughly investigated in the '30s and early
'40s by NACA, Wright Field and to a certain extent in England. Early
wartime V-12s used pure ethylene glycol and were non-pressurized, later
they switched to 50/50 and up to about 30 psi systems. The original reason
for all this, the 300 degree (F) cooling system was also thoroughly
investigated in the '30s but didn't make it into production, along with
steam cooling. 

Jim Davies