supercedar

I got the word today my all aluminum radiator cannot be repaired. They cleaned and repoxied it back together and it didn't hold. I am having them build a copper core with brass tank and they will reuse my oil coolers. They tell me it will have better cooling performance and that they build them like this for hot rods. The price seems fair at $550.00. They confirmed they still had the CNC software for this 928 style. Anyone ever try this?
Thomas

Landseer

You might have just created an important option for everybody.

Lizard928

I wouldnt be so sure about the copper over aluminum.

Why not just get a rebuilt factory rad?

Imo000

But ofcourse THEY will. Otherwise there is no business for them. Who is "They"?

blown 87

A brass core radiator will not transfer heat as fast as a AL one is my understanding.

Mrmerlin

I would find a good used Auto radiator or wait for Gregs radiator to come to market.
If you can find a used rad with a leaking end tank ,
new end tanks and o rings are available for about 95.00 per end tank then figure about 75.00 to have it installed. it should last another 15 years, make sure to do regular coolant changes

Mark Anderson

We have a good used C&R for $600 and it comes with a one year warranty

Tails

Thermal Conductivity - k - W/m.K of our radiator cores.

At 125 degrees C the thermal condictivity of materials for our radiators in question are:

Aluminium = 255
Brass = 109
Copper = 400

Conductive Heat Transfer
Heat transfer takes place as conduction if there is a temperature gradient in a solid or fluid

Conduction will take place if there exist a temperature gradient in a solid (or stationary fluid) medium.

Energy is transferred from more energetic to less energetic molecules when neighboring molecules collide. Conductive heat flow occur in direction of the decreasing temperature since higher temperature are associated with higher molecular energy.

Fourier's Law express conductive heat transfer as:

q = k A dT / s (1)

where

A = heat transfer area (m2, ft2)

k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))

dT = temperature difference across the material (K or oC, oF)

s = material thickness (m, ft)

From the above it can be seen that aluminum if a better heat transfer medium than brass, however, copper is the best.

I have an aluminium cored radiator fitted, but I have two spare brass or bronze units and I note that the brass/bronze radiators are nearly twice the thickness of the aluminium unit with more finned tubes fitted. I would suggest this is because of the thermal condictivity differential of the core materials to achieve the same cooling capacity.

Some may find this interesting.
Tails 1990 928S4 Auto

supercedar

This will be a copper core and brass tanks with larger tubes. Heinrich referred the shop. It is Seattle Radiator. They build aftercoolers and Radiators. Mostly industrial stuff.

They tried to repair for $200.00 and gave it a couple hours of labor and just gave me a choice of building one or I could go elsewhere. They were not going to charge for what they did and I felt I should give them a chance at making something. I will go with it and see how it works.

supercedar

Whoa, I can't wait to drive my 928! I just want to get her done and not look back.
Thomas

supercedar

Thanks Mark, Leif mentioned you as a option. I did give you 500.00 already this week and I received great parts and 3 day service. Tom was awsome!

I will go with new on this part, I don't care for the aluminum quality, so I will take my chance I guess.
Thomas

Lizard928

Thomas,

If you can make it up to this neck of the woods I have a radiator that I rebuilt which I can sell you at a reasonable cost.

I am just north of Sumas WA.
Feel free to ask the rest of the WA group too. And if you are not on the mailing list PM Tom M. on here.

supercedar

Thank you for your offer, I just can't go back on my word to the shop. They have invested alot of time for no pay and I feel right by giving this to them.
Thomas

S4ordie

Please take pics of the radiator before you install it. There are many here interested in what this shop will produce.

supercedar

[QUOTE=S4ordie;7905634]Please take pics of the radiator before you install it. There are many here interested in what this shop will produce.[/QUOTE

Yes I will take plenty of pictures and it should be the end of next week.