Re: More Antifreeze

["Chris Blumenthal" <chris@wallaby.corp.sgi.com>]

On Oct 30,  8:45am, Michael Spiers wrote:
> Subject: Re: More Antifreeze
> > I think that the Sierra product uses propylene (sp?) glycol as opposed to
> > ethelyene glycol. If the product is pure propylene glycol, it is safe to
> > ingest. However, it seems like there must also be additives that wouldn't
be
> > safe.>
> > I thought that propylene glycol was only usable in high flow,
non-pressurized
> > systems...?
> >
> I was working at NAPA on Saturday, and had a guy come in to buy some
> antifreeze.  "You guys carry Sierra?"  "No sir, we carry this NAPA crap, I
use
> it in all my cars."  "Good thing.  I've put Sierra in three cars, and each
car
> blew a water pump three weeks after I put the stuff in."
> Does this have anything to do with the propylene glycol business?  I'd never
> heard anything about Sierra, good or bad, so maybe this guy just had bad
luck?

There was an article some time ago in European Car about a business in the
eastern part of the US that had devised a propylene glycol conversion for
automobile cooling systems. My remembrance of the article is that the system
was designed to run at atmospheric pressure, used almost pure propylene glycol,
and was supposed to be capable of carrying off substantially more heat (like,
+50%) than a standard, ethylene glycol based system. This was supposed to cure
a host of ills in an engine, like pre-ignition, detonation and the like, thus
allowing more boost in turbo cars and more timing in regular induction cars. I
seem to remember that the system has other mods to allow a higher flow rate
than for the normal, pressurized 50% ethylene glycol/50% water systems.

It may be that the Sierra product is intended to be used as a "normal" mixture
(50%/50% or thereabouts); I have never read the instructions on the container.
Anyway, I am not sure how the fluid used would "blow" water pumps, which tend
to fail for mechanical reasons. I suppose that excess heat could hasten the
failure of a water pump, but I am not sure what other factors would have such
an affect.

Chris Blumenthal
'92 A6 Quattro Wagon