Aluminium radiator vs standard

[Stephen Pickard]

I have a 2.0l Vauhall VX. Radiator needs replacing. What advantages does aluminium radiator offer over standard. I understand this was used on Vauhall race cars and i believe the JPE.

[alan c]

I replaced my standard radiator with an aluminium one from Radtec and I have found that it is much better at keeping the tempearture down on hot days. Cannot comment on the CC version.

Still have the standard rad if you decide to go for simple replacement. I have been meaning to advertise this and some other stuff for ages.

Alan

[guilleracing]

There is a VERY minimal saving in weight, not really worth any performance gain however, an alloy radiator will radiate heat at a faster rate than a copper one.

 

We have had a fair bit of experience of cooling issues on racing single seaters. Without exception and alloy radiator of the same size radiates heat more efficiently than a copper one. A further improvement is to use a special paint that increases to exchange of heat but it may not be worth the extra expense.

 

I would recommend going for the alloy one simply because of my many good experiences with them.

 

 

Greg.

[Jonathan Kay]

That's interesting, Greg. I know very little about car radiators but I would have thought the heat transfer was mostly convective and would depend on airflow, surface area and conduction through the radiator. Copper conducts heat better than aluminium.

 

Could the effect you have observed be due to aluminium allowing a better design? I found one article that suggests that: See discussion of tube sizes.

 

If the radiators you compared were identical apart from material that couldn't be the reason.

 

Thanks

 

Jonathan

 

 

Edited by - Jonathan Kay on 28 Sep 2011 14:15:47

[guilleracing]

Well,,,,,,, not being a physicist I couldn't comment on the relative conductivity of Copper against Alloy Aluminium. I am only speaking from a point of view of personal experience.

 

I do have 30 years experience of motor racing at National level and have found by experimentation, that Alloy Radiators of the same dimensional size differences in construction aside, do reduce the overall temperature in service. It is a proven fact for example the the 1982 Van Diemen RF82 FF2000 overheats in temperatures over 30 deg ambient air temperature with Copper Radiators. They do not overheat with Alloy Radiators. The units must be identical as the FIA regulations demand parity. I know this to be a fact as I have one of these. The radiator situation is a well tried and trusted "Fix" with these cars. I also have a FVJ 1600 which I have re-radiatored like for like as the space is limited and the results are the same. I am not a techno bod on paper, I can only tell you what works in the real world. To be fair I would use Copper ones as they are cheaper but my experience tells me the Alloy ones work better.

 

Given the indicated superiority of Copper over Alloy Aluminium, I am bound to ask if there is a reason Formula 1 teams don't use the material in their radiators. Money can't be an issue with them! 😬

[Jonathan Kay]

Thanks

 

Jonathan

[andy_h]

The Ali rad in my 2.0l VX Challenge race car here is bigger than the normal ali rad sold by CC (from what I can see on their site).

 

 

[Rusty Bolthole]

I have a triple pass ally rad for sale which would suit a vauxhall as it has the correct size hose connections. Let me know if you are interested

[skeetsy]

Quoting guilleracing: 

Given the indicated superiority of Copper over Alloy Aluminium, I am bound to ask if there is a reason Formula 1 teams don't use the material in their radiators. Money can't be an issue with them! 😬

 

Well I can't say for sure but I suspect that it will be a compromise based upon the relative material weights (aluminium is much lighter than copper), the relative material strengths (aluminium alloys will be stronger than copper alloys) and the fabrication advantages which aluminium has over copper.

 

The lower heat transfer coefficient is probably a small price to pay in comparison to the weight and strength advantages.

 

All the best

 

Richard

[Paul Deslandes]

The only time I've had an overheating problem with my Vx, fitted with the standard copper rad, was when the fan thermostat failed in traffic in Rouen on a hot day. The solution then was to put the heater on full belt, albeit burning our feet in the process. Otherwise its never overheated, even in ambient temperatures above 30degC.

An empty ali rad is a quite a bit lighter than the copper version although I suspect a lot of the difference in percentage terms is negated by the weight of the water contained therein. But, as they say, 'every little helps'.

The main reason that race-series cars run with much bigger rads with big fans is that they spend a lot of time slipstreaming the car in front. This means they're running in stalled air which, in turn, can't flow through the rad at a high enough velocity and reduces effective cooling.

One advantage of a copper rad is, if it gets a leak it, can be resoldered which you can't do to an ali one.

Both auto and domestic 'radiators' are all wrongly named as none radiate appreciably and all convect, either naturally or using forced air.

[Dickie Normuss]

I too still have the standard rad and have sat in 30 degrees + for hours on the way to Le Mans and have never had an over heating issue. I have replaced the rad switch for a lower temp though

[andy_h]

Yep, been through Rouen traffic on a hot day (Le Mans) too . 'Others' were overheating but my VX was fine. However, I don't have a rad switch for the fan (removed and blanked off) but an in-line (in the top rad hose) temp. sensor/relay with resistor pot to adjust the temp. to control the fan.

 

 

[Mr Locust]

Don't underestimate the benefits of durability and repair-ability when considering a radiator for your Caterham. In my personal experience of the Caterham application, aluminium radiators are neither of these.

 

If your copper radiator is leaking I would seriously consider getting it re-cored with a high efficiency core.