Alloy rads or not.
Discussion
Is this a serious thread?
Aloly rads are for racing only really. Copper is better at dispersing heat than ali, about 1/3 better. If you want the same cooling then that's a 1/3 bigger rad, although at half thye unit weight it will save you 1/3 the weight of a standard copper one but cost you ? £750? Most people seem to thonk it a good idea to add 1/3 to 1/2 in thickness to a copper rad so really you'd want an ali one to be double the standard thickness.
I think that this is only for racers really.
Aloly rads are for racing only really. Copper is better at dispersing heat than ali, about 1/3 better. If you want the same cooling then that's a 1/3 bigger rad, although at half thye unit weight it will save you 1/3 the weight of a standard copper one but cost you ? £750? Most people seem to thonk it a good idea to add 1/3 to 1/2 in thickness to a copper rad so really you'd want an ali one to be double the standard thickness.
I think that this is only for racers really.
Thanks Jonathan. Knew the answer would be out there somewhere. Right, thats waste of money for me then. A few misconceptions picked up on my part.
Thinking aloud. So a larger core required? Can that be done with an existing rad to a certain degree?
Maybe a new ordinary large one?
Problem is the temp creeping up in traffic. Manual override with two fans only just keeps it under control. Would rather pay for a new rad now than new heads at a later date. Under way its OK. The rad was flushed during the rebuild and it has behaved much the same from then.
Thinking aloud. So a larger core required? Can that be done with an existing rad to a certain degree?
Maybe a new ordinary large one?
Problem is the temp creeping up in traffic. Manual override with two fans only just keeps it under control. Would rather pay for a new rad now than new heads at a later date. Under way its OK. The rad was flushed during the rebuild and it has behaved much the same from then.
stainless_steve said:
My rad has the standard rover core,single fan with a cowl,at the rear of the cowl there are two large holes with rubber flaps over.Never had any probs with it over heating.
OK so your SEAC certainly has a lot of power/heat; I don't think that Jeff's has the cowl. Also is the whole of the rad in that 400 getting to the same hot temp? ie does it need a new core anyway?
Well I'm a firm believer in ally rads. The original rad on the SEAC (which had been upgraded from standard) did not cool adequately in high ambient temps when pressed really hard although it was OK for road use. I had a new one built by Allards in Monmouth using the old one as a pattern. It took a while but we also took the opportunity to put bigger tanks in and it has built-in brackets for a twin fan set up - very tidy. Using an adjustable Otter Switch in the top hose and getting rid of the Otter switch the cooling has been transformad and so far I have had no problems even with a substantially uprated engine. If remember rightly the cost of the Rad itself was well under £400 - so not really that expensive in my view.
19560 said:
Is this a serious thread?
Aloly rads are for racing only really. Copper is better at dispersing heat than ali, about 1/3 better. If you want the same cooling then that's a 1/3 bigger rad, although at half thye unit weight it will save you 1/3 the weight of a standard copper one but cost you ? £750? Most people seem to thonk it a good idea to add 1/3 to 1/2 in thickness to a copper rad so really you'd want an ali one to be double the standard thickness.
I think that this is only for racers really.
Interesting, not a wedge but a V8S similar era. When I had mine re-cored earlier this year it was certainly light, it was made with a silver type metal that didn't have rust on it. I would have thought given the above the standard should be copper but I'm sure the S is sourced as a modified leyland daf sherpa van type one, with an extra core. Would have put money on it being an alloy
. harry
Harry
Brm Brm said:
Well I'm a firm believer in ally rads. The original rad on the SEAC (which had been upgraded from standard) did not cool adequately in high ambient temps when pressed really hard although it was OK for road use. I had a new one built by Allards in Monmouth using the old one as a pattern. It took a while but we also took the opportunity to put bigger tanks in and it has built-in brackets for a twin fan set up - very tidy. Using an adjustable Otter Switch in the top hose and getting rid of the Otter switch the cooling has been transformad and so far I have had no problems even with a substantially uprated engine. If remember rightly the cost of the Rad itself was well under £400 - so not really that expensive in my view.
I'm only against the price. If one goes down that route then I think that one needs to follow your actions. The otter switch move is a good idea anyway. £400 is half the cost of what many have paid so well done and thanks for posting the name of the firm, but it's still a lot more than a copper one.
>> Edited by 19560 on Wednesday 26th May 00:31
HarryW said:
Interesting, not a wedge but a V8S similar era. When I had mine re-cored earlier this year it was certainly light, it was made with a silver type metal that didn't have rust on it. I would have thought given the above the standard should be copper but I'm sure the S is sourced as a modified leyland daf sherpa van type one, with an extra core. Would have put money on it being an alloy
I haven't heard that but its not too surprising. the V8S is later in design than the wedges. At about that time the price of copper shot up and for a short time it was economic for mainstrem manufacturers to use aluminium rads. If you can find a good one in a scrap yard then this would be a good cheap solution. Unfortunately good rads in a scrap yard are not much rarer than good tyres; scrap yards are also becoming rare.
19560 said:
OK so your SEAC certainly has a lot of power/heat; I don't think that Jeff's has the cowl. Also is the whole of the rad in that 400 getting to the same hot temp? ie does it need a new core anyway?
Ah, something to check when I can. Forgot about that. Temeperature across the rad after a run. Either way I think its OK so a bigger will be required. But to check it is easier and cheaper so will do that when I can.
And no, no cowl. Both fans are flush to the face of the rad. I only removed the single fan as it had siezed and the cowl as the new fans wouldn't fit (and some advice, not from on here).
Also it seems the otter switch needs relocating as per Russ's SEAC. Variable otter swith? Will get on the blower sometime this week, sounds interesting.
Cheers all
PS tell tales on the core plugs have shown 110 deg when my gauge never went past 90. Probably a red herring.
>> Edited by jmorgan on Wednesday 26th May 08:52
The 520 has a custom one made by Docking Engineering at Silverstone. It will fit but I did not mount the fans on it. Costs around £375. Ally is more efficient at cooling because it is more maleable and allows a higher core and fin density. It is lighter as well. I didn't have the fan mounts added to the rad because I moved them so I could replace them very quickly.
I had to severly restrict the front air intake to prevent the rad over cooling the car.
I had to severly restrict the front air intake to prevent the rad over cooling the car.
19560 said:
Is this a serious thread?
Aloly rads are for racing only really. Copper is better at dispersing heat than ali, about 1/3 better. If you want the same cooling then that's a 1/3 bigger rad, although at half thye unit weight it will save you 1/3 the weight of a standard copper one but cost you ? £750? Most people seem to thonk it a good idea to add 1/3 to 1/2 in thickness to a copper rad so really you'd want an ali one to be double the standard thickness.
I think that this is only for racers really.
Sorry but I disagree completely. Competition radiators are invariably aluminium because these dissipate dramatically more heat than the equivalent sized copper rads. Cu/Brass rads used to be more popular for production cars because they are slightly cheaper in volume. Aluminium brazing techniques have improved enormously over the last few years and the aluminium rads are now much better and cheaper than they were say ten years ago. My current aluminium rad is much thinner than the original copper one but it has far less restriction on the air and water flows and provides far better thermal connection between them. Result is dramatically increased heat dissipation.
If you have a choice, go for a vertical flow alloy rad. These have much lower thermal stresses than horizontal flow rads so can be made from thinner material and with a much higher aluminium content, which is cheaper and lighter and conducts heat better. The horizontal flow rads need a stronger alloy to cope with the thermal stresses but this costs more and doesn't conduct heat as well.
They are called radiators, but they don't.
They work mainly by convection. What is important is the mass of air you can rub past the surface of the radiator fins in a given time. Given that aluminium has an emmisivity of 0.08 compared with 0.98 of black painted anything, it would be a poor choice if radiation was the real heat vector. You might, perhaps have a teeny weeny advantage in an alloy radiator if the fins were anodised, but it would be really marginal, a few percent at best.
I would suggest that your fan is not close enough to the radiator to pull air through it, try making up a cowl out of ally foil, so the fan is made to pull air through the radiator, and not just waft it around at the back.
Hope this helps. I've tried to be accurate with the thermodynamics, but if anyone else knows different please say.
They work mainly by convection. What is important is the mass of air you can rub past the surface of the radiator fins in a given time. Given that aluminium has an emmisivity of 0.08 compared with 0.98 of black painted anything, it would be a poor choice if radiation was the real heat vector. You might, perhaps have a teeny weeny advantage in an alloy radiator if the fins were anodised, but it would be really marginal, a few percent at best.
I would suggest that your fan is not close enough to the radiator to pull air through it, try making up a cowl out of ally foil, so the fan is made to pull air through the radiator, and not just waft it around at the back.
Hope this helps. I've tried to be accurate with the thermodynamics, but if anyone else knows different please say.
I was advised (by a man who designs engine cooling systems for a living) to leave an air gap of at least 1cm between the matrix and the blade of 'puller' fans, to allow the air flow to steady before hitting it with the fan blade. Fans are quite sensitive to small scale turbulence and there's a fair bit of that immediately downstream of the matrix.
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