Re: Alum. vs Copper RE: I need a radiator for an 88 80q , where to buy?????

["Fred Munro" <munrof@isys.ca>]

An observation on the Al/Cu subject:

    I have just replaced the A/C condenser on my '91 200q with an
after-market unit. The new condenser appears to be made of Cu ( at least
where the paint is scraped off one of the tubes - must go out and repaint
that spot before salt season) and has a much higher fin density than the OEM
condenser, which I think was Al.
    The last few days have been quite hot, so the A/C system got a good
workout. The A/C blows much colder than the original system ever did and the
engine is running 3 - 4 C hotter than normal.
    The new condenser appears to be dumping more heat than the OEM unit,
probably due to the higher fin density and perhaps due to the Cu
construction. The A/C also cools down faster and seems more effective around
town at low speed.

Fred Munro
'91 200q  277k km (cool car!)

----- Original Message -----
From: Claus Vegener <vegener@post7.tele.dk>
To: quattro audifans <quattro@audifans.com>
Sent: Friday, July 23, 1999 8:45 PM
Subject: Sv: Alum. vs Copper RE: I need a radiator for an 88 80q , where to
buy?????


> Talking Thermal Conductivity Kenn is right, but the biggest problem
> in heat transfer is not transfer of the heat from the innerside of the
> CU or Al tube through the metal and to the outher side of the finns.
> It is the crimping of finns CU or Al to the inner tube and the
> extern heat transfer coeffcient [W/(m2 * dT)] for the air, which is the
> heavy one.
> And besides:
> The resulting effectivity of  fin's of equal sizes depends on the square
rot
> of
> their thermal conductivity. Hense the advantage of Cu to Al is
> (390/239)^.5 = 1.28
> The Cu fins should be 28% better but is more heavy and more expensive.
> So look at the area, number of fins and the tube surface, if you have to
> compare 2 radiators.
> In the first step from inner tube to outer tube the material don't matter.
>
> Kind regards Claus
>
> ----- Oprindelig meddelelse -----
> Fra: Kenn Thyrsted <thyrsted2@olsy.dk>
> Til: Avi Meron <avi@cosmoslink.net>; <River6822@aol.com>
> Cc: Quattro <quattro@audifans.com>
> Sendt: 24. juli 1999 00:30
> Emne: Re: Alum. vs Copper RE: I need a radiator for an 88 80q , where to
> buy?????
>
>
> > Actually Copper is better than Aluminium.
> > Cu=390W/(m*deg)
> > Al=239W/(m*deg)
> >
> > Ordinary Brass (Yellow) is 112W/(m*deg)
> >
> > /Kenn
> > ----- Original Message -----
> > From: Avi Meron <avi@cosmoslink.net>
> > To: <River6822@aol.com>
> > Cc: Quattro <quattro@audifans.com>
> > Sent: Friday, July 23, 1999 7:26 AM
> > Subject: Alum. vs Copper RE: I need a radiator for an 88 80q , where to
> > buy?????
> >
> >
> > > Scott,
> > > Aluminum dissipate heat much better and faster than brass or copper,
you
> > can
> > > get away with an alum. rad. that is smaller than brass, that is one of
> the
> > > main reasons while most (almost all)OEM radiators and AC evaporators
are
> > > made out of alum.
> > > If you have difficulty with my statement try to heat a copper pipe and
> and
> > > alum, pipe, you will find out very quickly which material conduct heat
> > > better. The only advantage that brass has over alum. (rad.) is
> durability.
> > > Avi
> > >
> > > -----Original Message-----
> > > From: owner-quattro@audifans.com [mailto:owner-quattro@audifans.com]
On
> > > Behalf Of River6822@aol.com
> > > Sent: Thursday, July 22, 1999 7:51 PM
> > > To: obin_olson@hotmail.com; quattro@audifans.com
> > > Subject: Re: I need a radiator for an 88 80q , where to buy?????
> > >
> > > You will not find a new radiator for less than $175. I put one in my
88
> > 80q
> > > about 6 months ago. What a PITA. I got mine from a local radiator shop
> > that
> > > carried a generic brand-- i'm not sure of the name. The shop is in
> Glasco
> > > NY,
> > > I don't know where you are located. Anyway, I know it was not a
Modine.
> > >
> > > The radiator is a copper core, the original is aluminium. Don't let
> > anybody
> > > fool you, copper disappates heat faster than aluminium. It has been
> > working
> > > fine and the running temperature is below what the old radiator ran
at.
> > >
> > > Hope this helps.
> > >
> > > Scott Calabrese
> > > 88 80q
> > > http://members.aol.com/river6822
> > >
> >
>
>
>