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Radiators
CosKev3 - 23/8/14 at 09:37 AM

Morning

Anyone knowledgeable on cooling?

Would a alloy down flow rad with a core size of 32w x18h x5d offer more cooling than a standard cross flow rad with a core size of 33w x31h x2.5d?

Would the alloy rad cool a R1 BEC well enough?

The standard core size above is the standard R1 rad.

Cheers.

cliftyhanger - 23/8/14 at 09:50 AM

Doubling depth will not make up for halving area.
Double depth maybe a 25% area reduction? Bit of a guess that.

britishtrident - 23/8/14 at 11:48 AM

Thick core requires more air pushed through it to cool efficiently.
More closely packed fins require a greater air pressure pushing the air through the rad to show a cooling gain.

CosKev3 - 23/8/14 at 03:36 PM

Ok cheers

quote:
Originally posted by cliftyhanger
Doubling depth will not make up for halving area.
Double depth maybe a 25% area reduction? Bit of a guess that.


Halving area?
It's a long way off half the area!!!

matt_gsxr - 23/8/14 at 08:05 PM

Polo radiator is something of an accepted standard (and fine for BEC's).

Polo rad dimensions are approximately 19inch by 13inch.

So I'd guess you'd have plenty of cooling.

Matt

p.s. the rad in the bike is even smaller.

daviep - 23/8/14 at 08:40 PM

quote:
Originally posted by CosKev3
Ok cheers

quote:
Originally posted by cliftyhanger
Doubling depth will not make up for halving area.
Double depth maybe a 25% area reduction? Bit of a guess that.


Halving area?
It's a long way off half the area!!!


It's almost exactly half the frontal area, 56% ish

britishtrident - 23/8/14 at 09:17 PM

With heat exchangers you have to look at total surface area that is total area of the tubes and the fins.
A rad with closely packed fins like and old style Mini brass rad has a lot of heat transfer area but presents more blockage to the air flow compared to for example a Cortina/Escort rad which has less closely pack fins.

A Polo alloy is very efficient it has a good compromise between fin density and air flow.

CosKev3 - 24/8/14 at 08:26 PM

Cheers

Looking inside the alloy rad I've noticed its got three rows of cooling tubes deep,not just a single 5cm tube,so this will help cooling?

quote:
Originally posted by daviep
quote:
Originally posted by CosKev3
Ok cheers

quote:
Originally posted by cliftyhanger
Doubling depth will not make up for halving area.
Double depth maybe a 25% area reduction? Bit of a guess that.


Halving area?
It's a long way off half the area!!!


It's almost exactly half the frontal area, 56% ish


Am I being thick?

Surely 50% of 33w x31h is 16.5w x15.5h?

How can 32w x18h=56%?

mark chandler - 24/8/14 at 08:34 PM

I look at things more simply, the standard rad on a R1 is a tiny little affair, granted that on a bike it will not be worked as hard at any given speed but most small car rads are up to the job.

I run a polo rad, pre turbo it was fine, post turbo I needed to add an oil cooler and sort out the ducting to prevent air leaks.

Slimy38 - 24/8/14 at 08:42 PM

quote:
Originally posted by CosKev3

Am I being thick?

Surely 50% of 33w x31h is 16.5w x15.5h?

How can 32w x18h=56%?


56% is right. 33 x 31 surface area is 1023, 16.6 x 15.5 surface area is 255, which is 25% not 50%.

[Edited on 24/8/14 by Slimy38]

britishtrident - 25/8/14 at 07:10 AM

quote:
Originally posted by Slimy38
quote:
Originally posted by CosKev3

Am I being thick?

Surely 50% of 33w x31h is 16.5w x15.5h?

How can 32w x18h=56%?


56% is right. 33 x 31 surface area is 1023, 16.6 x 15.5 surface area is 255, which is 25% not 50%.

[Edited on 24/8/14 by Slimy38]


But that is the frontal area not the heat transfer area.
The depth and fin density also have to be allowed for.