Rad modifications?
Discussion
What are the best ways of making a radiator more efficient?
My 500E has very little room and can happily run at 110°C without any problems but feels better running at between 80°C and 90°C. Pick up etc all better from a standstill and mainly, nicer for me as i'm always a bit dubious of it getting so high. It is pretty much designed to run at 98°C with the air-con on at all times but can take a while to recover to normal running temps after slow uphill drives or long periods in high temps.
So, I understand that sending my rad off to have a copy made from ali should give me better cooling, but is this guaranteed due to the material or is this generally because it has a greater capacity etc?
I wont be making any changes at all mechanically, still want to keep my viscous fan and air con rads etc all in the standard positions so want to know i'll get the benefits if I ask for an exact copy to be made.
Dave!
My 500E has very little room and can happily run at 110°C without any problems but feels better running at between 80°C and 90°C. Pick up etc all better from a standstill and mainly, nicer for me as i'm always a bit dubious of it getting so high. It is pretty much designed to run at 98°C with the air-con on at all times but can take a while to recover to normal running temps after slow uphill drives or long periods in high temps.
So, I understand that sending my rad off to have a copy made from ali should give me better cooling, but is this guaranteed due to the material or is this generally because it has a greater capacity etc?
I wont be making any changes at all mechanically, still want to keep my viscous fan and air con rads etc all in the standard positions so want to know i'll get the benefits if I ask for an exact copy to be made.
Dave!
A brand new rad of original spec will be more efficient than the (presumed) old one you have now. The same design in ali will be even more efficient.
However none of this will guarantee a reduction in temperature as we have no idea if there are other problems like a water pump with an eroded impeller.
Sounds like a good plan though.
Steve
However none of this will guarantee a reduction in temperature as we have no idea if there are other problems like a water pump with an eroded impeller.
Sounds like a good plan though.
Steve
Two of the most important things to check are that the rad is fully ducted (the fans pull air over the whole surface area) and that it is sealed so that hot air from the engine side can't be drawn into the front. I don't know how good your viscous fan is but a good electric fan is likely to provide better air flow at low engine speed.
The fan is fully ducted and is working correctly as far as I can tell, I tested it engaging and it does.
It has 2 electric fans, one comes on at 98degrees, the other not till 105 degrees, these were both artificially lowered by fitting a resistor in paralell, a comoon mod to help low speed temps. With both fans going it sounds like a jet engine is stored under the bonnet but this has only happened a few times. 1 fan runs at low speed while the air-con is running and this is when I see it sit at 98 degrees when speeds are around the 30mph mark.
The price of a new radiator not far off the price of a custom one I had specced for a project of mine, but if it works better than the original i'm not so sure. Normally when i've seen someone have a custom rad made it is a larger size, greater volume etc.
This is the best picture I have of the front of the car where you can see any kind of fan, radiator assembly....
Dave!
It has 2 electric fans, one comes on at 98degrees, the other not till 105 degrees, these were both artificially lowered by fitting a resistor in paralell, a comoon mod to help low speed temps. With both fans going it sounds like a jet engine is stored under the bonnet but this has only happened a few times. 1 fan runs at low speed while the air-con is running and this is when I see it sit at 98 degrees when speeds are around the 30mph mark.
The price of a new radiator not far off the price of a custom one I had specced for a project of mine, but if it works better than the original i'm not so sure. Normally when i've seen someone have a custom rad made it is a larger size, greater volume etc.
This is the best picture I have of the front of the car where you can see any kind of fan, radiator assembly....
Dave!
I thought ali was used for race applications because it was a lot lighter than copper and the poorer conduction properties were compensated for with better design (bigger larger more etc). Not sure if a larger capacity ali rad saves you much weight though as waters weight is 1kg/liter.
IMHO best option is to fit a new standard rad, flush everything well and make sure everything is working as designed.
IMHO best option is to fit a new standard rad, flush everything well and make sure everything is working as designed.
leorest said:
I thought ali was used for race applications because it was a lot lighter than copper and the poorer conduction properties were compensated for with better design (bigger larger more etc). Not sure if a larger capacity ali rad saves you much weight though as waters weight is 1kg/liter.
IMHO best option is to fit a new standard rad, flush everything well and make sure everything is working as designed.
This was my fear about the ali rad.IMHO best option is to fit a new standard rad, flush everything well and make sure everything is working as designed.
Thanks for the help guys, new standard rad is looking like the best option then at the minute.
Dave!
One advantage of a good alloy rad is that they are thinner for a given cooling capacity, which means that they have much less restriction on the air side. That might come in handy since you would seem to be short of air flow. I can't figure out why though, since this problem seems to be self inflicted. From your description you have fans capable of delivering ample air flow but chose to set them up so that they don't come on under the conditions where you want improved cooling.
Copper is the better conductor, and will be more efficient. But as said, if the Ali one can be constructed with thinner tubes etc...then it can become more efficient.
But Ali also looks much nicer in there.
The obvious choice is a custom ally, with a much thicker core. Or even just a more efficient core than you are currently using. ie more tubes, more fins/gills etc... there are lots of options that can help.
This guy Richard ( 0798006818 ) made my custom rad, and did an excellent job, far cheaper than anywhere else I ordered from ( he used to work for Pace )
Puller fans also tend to be more efficient that pushers too.. So better fans could be another upgrade.
Spal make some of the best.
But Ali also looks much nicer in there.
The obvious choice is a custom ally, with a much thicker core. Or even just a more efficient core than you are currently using. ie more tubes, more fins/gills etc... there are lots of options that can help.
This guy Richard ( 0798006818 ) made my custom rad, and did an excellent job, far cheaper than anywhere else I ordered from ( he used to work for Pace )
Puller fans also tend to be more efficient that pushers too.. So better fans could be another upgrade.
Spal make some of the best.
GreenV8S said:
One advantage of a good alloy rad is that they are thinner for a given cooling capacity, which means that they have much less restriction on the air side. That might come in handy since you would seem to be short of air flow. I can't figure out why though, since this problem seems to be self inflicted. From your description you have fans capable of delivering ample air flow but chose to set them up so that they don't come on under the conditions where you want improved cooling.
In normal running, the air con fan comes on at 98°C, this is on low speed, at 105°C the second fan kicks in at low speed again, then when it hits 115°C they both go up to full.I've dropped it so the fans come in at a lower temp to stop it going past 100 preferably, as when it gets past that you really need to be doing about 60mph for it to get back to less than 100.
Sadly there isn't any space without removing the cowling to put puller fans in.
I will enquire about the ali rad though, I didn't know they were more efficient for the same cooling power.
Dave!
Howitzer said:
In normal running, the air con fan comes on at 98°C, this is on low speed, at 105°C the second fan kicks in at low speed again, then when it hits 115°C they both go up to full.
I've dropped it so the fans come in at a lower temp to stop it going past 100 preferably, as when it gets past that you really need to be doing about 60mph for it to get back to less than 100.
Chose the running temperature you want to aim for. Install a stat that will be fully open at that temperature. Set the fans up so they are all on at (say) 10C above that temperature. If the temperature keeps rising with all the fans on, you need more water flow, or more air flow, or a better radiator. You can find out which by monitoring the air and water temperatures on and off the rad, but no point doing that unless you have a problem. It still sounds to me as if you have adequate fans for the job but are trying to keep the engine below the fan-on temperature. You can only do that if you have adequate ram air, which you often won't.I've dropped it so the fans come in at a lower temp to stop it going past 100 preferably, as when it gets past that you really need to be doing about 60mph for it to get back to less than 100.
How long has the current radiator been in place, has it had a decent rad flush pushed through it, maybe its scaled up, if you filling the system with ordinary tap water, over time they will scale on the inside of the rad and lower the efficiency of the heat transfer.
I think a new OEM rad would make a great deal of difference over the old one, and a new lower temperature thermostat, personally i would only go for an uprated Ali rad if i was tracking it or racing it. Bearing in mind that lowering the temperature of the stat might affect the efficiency of the engine overall and you might have to compromise a small bit on the economy.
I think a new OEM rad would make a great deal of difference over the old one, and a new lower temperature thermostat, personally i would only go for an uprated Ali rad if i was tracking it or racing it. Bearing in mind that lowering the temperature of the stat might affect the efficiency of the engine overall and you might have to compromise a small bit on the economy.
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