radiator question

[Belgian1979]

I went to a radiator shop today. My current radiator is a copper/brass one with 3 rows and about 8 fins per inch. They say they have a bigger core that can have almost double the heat dissipation my current one has (apparently 4 cores and a different number of fins). I also enquired about aluminum. He said the aluminium will run 3-4°C cooler than the copper equivalents which is not a big difference. The biggest disadvantage is that alu is difficult if not impossible to repair.

So what is the opinion here ?

[gofaster]

The biggest disadvantage is that alu is difficult if not impossible to repair.

He's talking through his hat!

[Belgian1979]

Ok, but apart from that : the difference between getting a direct fit radiator from the us to having the existing one recored is USD 700 in total, so a big difference. I always read about the big difference in cooling, and so was suprised about the small difference he mentioned.

[wyrmrider]

Blowing smoke
Brass has better transfer than aluminum
you can go straight fin 16 fins per inch is about max
sq ft size is more important than width
you can also do multi pass
ALUMINUM IS MUCH LIGHTER
get a core book out and see what fits your headers, what size headers fit
is this downflow or cross flow?

[Belgian1979]

cross flow. There is not much to choose in size. The c/b rad barely fits between the fenders and the hood as is. If the replacement rad is the same physical size, it has to have either more rows and more fins or the higher capacity has to come from better heat transfer.

[wyrmrider]

actually your 3 row 8 fpi should cool most anything it's not like you are towing up hill in the desert in the summertime
are these zig-zag fins or straight?
If you go to straight fins there are fins that are skivved or louvered they work better
I take it you've pulled the tanks and flushed and none of the passages are blocked as coolant takes the path of least resistance (which is why multi pass flow is done- instead of left>>>right
it's left>>>>right down right<<<<<left down left>>>>right
have you looked at it with a temp probe?
700 is a LOT of $$$ for an essentially standard radiator
remind me what this goes in
Wish you were here...I have a super radiator/ racer compadre
If you get me details I'll ask him

[Belgian1979]

Radiator went in before I started to use it and they repaired some holes, tested and flushed it. Have approx. 1200 mils on it since then.
Fins are straight top to bottom.

I've not had a problem when on the mechanical fan. Now with the electric fan, they cool the car down at idle no problem. At 2000-2500 rpm she seems to want to run hot and it seems to cool more when I up the rpm.

Yes, the 1.25" tubes alu rad is approx. USD 1000 with shipping and taxes.
Recoring is around USD 400 locally. I have a spare rad that I can use for this purpose.

I could also go back to the mechanical fan, but that means not having a cold air intake and breathing hot 130-135°F air temp.

[BlackoutSteve]

I think the "alum cools better than copper" misconception comes from the larger size of the alum rubes -alum being stronger, they can be made larger.
So an alum 2 core is about the same size in width as a copper 4 core.
So without realizing the tube sizes, it sounds like 2 alum cores can do the job of 4 cores of copper.

[Belgian1979]

That's what being said, but in addition to that it's said they cool better. My idea is this might not be such a big difference, but I have no experience with them.

I have also though using a 1.24/1 pulley ratio vs the 1/1 I have now but since my engine is a high rpm unit, it could mean running into pump cavitation at high rpm.

[wyrmrider]

http://www.hotrodhotline.com/content/al ... s-radiator

http://automotivepartsuppliers.com/copp ... radiators/

http://www.usradiator.com/cores

what chassis Belgain?

[#84Dave]

In the latest issue of the performance magazine, Speedway Illustrated, there is an outstanding article regarding the cooling fan/shroud assemblies. Mechanical or electric. The article is very technical in nature. -Dave-

[wyrmrider]

dave- is there a link
tks

[Krooser]

While I have two 'racing' aluminum radiators on the shelf and another in my kid's dirt modified they wouldn't be there except for weight reasons. I've always liked copper/brass...

[Belgian1979]

Yes, when looking at the links above I think the radiatorshop is thinking about a 4 row on 5/16 centers with more fins per inch. Not sure how that relates to btu's when comparing to for instance the more generic alu radi with 1.25" tubes.

Weight is not my my mayor concern.

[wyrmrider]

That's what I do on the Motorhomes
and select the fin materiel

anotherthing
many use thick insulating paint
use flat black
or surplus zinc chromate thinned like a wash
brash must be chemically clean before painting

what chassis belgain- I know you've posted it elsewhere but I forget
cheers
and
what Krooser said xxx000
Dualie thawed out yet?