164 Aircon - R134a

["John Wiltshire" <John.Wiltshire@domain.elided>]

Sorry for a post that is well out of date, but I've been away for a couple
of weeks and I'm just skimming through some old digests now.

I  can't remember who started the thread about converting 164 A/C  to 134a,
but here's my two bob's worth.

My 164 has been converted to 134a. It certainly isn't as good as a system
that is designed for 134a, but it has survived through three Sydney summers
without too much grief.  Here are a few thoughts on maximising the
efficiency of the system:

*  One of the stumbling blocks of the 164 system is that the compartment
between the windscreen and the false firewall can get hot from engine heat.
Check that the false firewall itself is properly in place - this if held in
by clips at the bottom and screws at the top, and because if the tight
access behind the engine, it is easy to not have these bottom clips
properly located, and so there is a gap of about 6-8mm directly above the
exhaust manifold.

*  The rubber seal along the top of the false firewall can deteriorate, and
so this needs to be replaced to keep engine bay heat out of the A/C
compartment area.  Fellow Digester Dave Jarman suggested a while ago that
feeding a length of filler rod through the centre of the seal will renew
it's spring and therefore its sealing properties.  (I think it's called
filler rod.  It is used for concreting and it is an expanded plastic foam
about 10mm in diameter that is used in concreting.  Available from building
supply shops for about $1 per metre).

*  There is a rubber sealing donut between the A/C evaporator group and the
blower fan housing.  This must be sound and well-sealed.  The 164 blower is
placed after the  evaporator and sucks air through.  If the donut is
leaking, the blower will suck in hot air that hasn't been through the
evaporator.

I think that my rubber donut is on the way out.  I had the A/C regassed
just before Christmas last year.  In stop and go traffic, it is trying
pretty hard, but as soon as the car is moving, the A/C cools down quickly -
no doubt aided by the high pressure air in front of the windscreen being
forced through the condenser, and so negating any effects from the leaky
donut.

The other thing that I find with the 164 is that if I open the boot after
driving with the A/C on, it is like a refrigerator.  Obviously very good
flow-through ventilation working here, so make sure that the vent outlets
in the boot are not clogged.

In short, although 134a is not brilliant in a 164, you can easily live with
it if the rest of you A/C system is up to the mark.

A the risk of starting up a thread on another old  non Alfa related
subject, the question was asked as the why Mazda didn't put their small V6
into the Miata/MX5.  I would ask why they didn't put a rotary engine in it?
I'm in full agreement with Michael Smith about Mazda making some fine small
cars.  I still have my old 626 living in my mother's garage awaiting some
TLC to get it back on the road.  It was my daily driver/club car for years,
and with a bit of tweaking it was a really fun drive.

Stay cool!

Cheers,
John Wiltshire
Sydney Australia

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