A happy story with Evans coolant (formerly - a horror story)

[ikessel@worldnet.att.net]

Brandon Hull wrote:

> >problem, the S4 clearly did not like it.  Igor, what has been your
> >experience?

An entirely positive one, except for the "growing pains" of the first
few mos when the PPG would boil out due to my failure to evacuate (read
- laziness) the last 2L of water from the block jacket. This was
successfully corrected by adding an aux expansion tank and a Vanagon cap
w/valve removed. No more coolant geysers observed.

1. I did replace the heater core at the same time. 

2. My water pump is relatively new, GRAF, made out of Al w/steel
sprocket.  I always CNC-machine a larger groove in the WP sealing flange
and use an oversized O-ring (actually it's Imperial sized but for our
purposes here it's ~5mm). I have never had a problem with a leaky WP
since I started doing this in '91; so far I have done about 5 Audis this
way (Mike Zamikhovsky's 5000TQ is one of them).

3. I flushed and drained the radiator completely, _off_ the car. It is
reasonably new, plastic, 2-row OEM.

4. I am running the coldest Audi thermostat that I could find (78œ, the
P-car application). Audi fiche does not show it, so don't bother folks.
Go straight to an aftermarket P-car supplier. 
On top of that, I drilled 3 or 4 1/8" DIA holes in its disk to
facilitate the minuscule flow of the somewhat thicker Evans coolant at
the colder ambient tœ-res as per an advice of both George Baxter and the
Evans product development engineer.

Although there are some highly esteemed wrenches on this List who
wouldn't agree with me, I do firmly believe that a colder thermostat is
a good thing on a highly stressed chipped turbo engine (I am running
18psi of boost on my low compression MC-1 with a big K26 turbo).

The sole purpose of the thermostat existence in a car is to enable the
flow of the coolant _only_ through the small circuit (pump -
block_jacket - head_jacket - heater_core (only if the heater valve is
open)) while the tœ-re is below its opening tœ-re [78œ on mine] hence
expediting the warm-up process. Upon reaching the said tœ-re the coolant
starts to flow through the big circuit (small circuit + radiator).

The colder thermostat _does_not_ make the engine run cooler. It rather
makes the engine reach the operating tœ-re sooner, cutting down on the
cold start induced wear.

The radiator thermoswitch opens at 93œ and closes at 88œ and the fact
that on my car the fan cycles on and off normally indicates that the
coolant remains  more or less isotermic within the said hysteresis and
that the colder thermostat _does_not_ make the engine run below the
normal operating tœ-re of the engine.

The afterrun sys cycles absolutely normally as well, which indicates a
good and consistent convection of the PPG coolant inside the radiator.

Consistent with the Brandon's observation of his car, on my '89 200TQ at
highway speeds the water temp needle remains at one-third of the dial,
between 10:00 and 11:00. In traffic the water temp needle is at about
13:00.

It acted about the same with the regular 5:2 mixture of water/ETG
antifreeze before that, so I don't see a reason to worry.

> >Avi Meron wrote:

> >The car (5K turbo Q, 2 bar boost), experienced overeating problems from the
> >first day of converting to Evans, numerous attempts to get in contact with
> >one of the list members that has performed  the conversion failed.

That wouldn't be I, Avi, would it? My "Sent" folder has a total of 7
direct replies to your enquires RE: Evans coolant dated Fall '97 - Jan
'98. I am very sorry that Evans caused such a disaster on your car, Avi,
although my own experience and that of a few other Listers contradict
your conclusion. Perhaps the problems lies elsewhere?

Is it possible that either your radiator was clogged or the thermostat
was stuck closed? In my view either of the above would cause the
overheated coolant run trough the small circuit only, hence preventing
the radiator thermoswitch from activating the fan with the obvious dire
consequences.

> >My conclusion is that the Audi water pump (in the configuration that we have
> >in our turbos) can not pump the thick Evans coolant,

I vaguely recall from the Evans brochure that in some cars the reversal
of the coolant flow was needed.

> my Audi contact (Mike
> >at Inglostat West) confirmed the theory by describing similar symptoms when
> >100% coolant (the regular water base) is used.

I disagree here. In the winter of '91 I ran the 100% pure antifreeze in
my '85 5000s and the water pump handled it fine (having driven a
multitude of cars all year round in northern Russia just a few years
before then, I had habitually replaced the water-based coolant with the
pure antifreeze).
I eventually ditched the idea coz in the very first brutal Philly summer
the car started to overheat and lost the top radiator nipple (what else
is new, right? :-) and I immediately realised that although the boiling
point of ETG is a lot higher than that of water, its Q (the heat
capacity) is about one-half of that of water and so was its ability to
transfer the heat from the hot side to the cold side in the cooling sys.
Of course back in northern Russia (Leningrad) this was not an issue coz
July overthere felt like November overhere. 

Oh, one more thing. Somebody has been recently contemplating a turbo
line replacement and asked about the best way to drain the coolant from
a 200.
I do it without spilling a single droplet (of that $27.50/gallon Evans)
by
undoing just the two 5mm Allens at the flange of the bottom turbo
coolant line.
This line has about 5-6mm ID and if you keep the reservoir cap unscrewed
it would give you a very accurate, albeit slow, creek of coolant which
is very easy to collect in any suitable container. Once underway,
unscrew the reservoir cap to expedite the coolant drain.
This method eliminates the needless draining of the 2/3 of the radiator
and of the whole of the engine block.

A final note: the regulars might have noticed that I seized posting a
few mos ago. Currently I am unsubbed due to a totally insane schedule
and will remain to be off-List till at least late Feb. Although I do
check the archives periodically, I fish out only the posts that are of
an immediate interest RE: my own car, although there are some Listers
who's posts I read regardless of the application (you know who you are
:-). Folks, if you have any questions, please address them directly to
me, otherwise I might miss some of them and create a wrong impression
that I neglected to answer.

In the early '99 I will be buying a scanner and at that time should be
able to deploy a useful site dedicated to the type-44, A4, my own
McGuyver hacks etc. 

Happy New Year to all of you!

--
Igor Kessel
Two turbo quattros












a4