radiator and fans - what's recommended?
Discussion
I'm the owner of a '92 4.3 big-valve Griffith and new to posting on the site; any advice gratefully received.
I got the car summer before last, and it's been tremendous. I'd fancied one for some time and it's really exceeded expectations.
It does run rather hot, in spite of having been checked over by Team Central and having the Otter switch replaced. I suspect it's because the radiator and fans are rather tired and less efficient than they used to be.
I'm aware that fitting a new aluminium radiator is a well-tried mod and that's what I'd like to do, along with new fans. What is recommended by posters here? I've read about an impressive-sounding company called Coolex Heat Transfer in Nottingham. Does anyone here have any experience with them?
Thanks!
Andy
I got the car summer before last, and it's been tremendous. I'd fancied one for some time and it's really exceeded expectations.
It does run rather hot, in spite of having been checked over by Team Central and having the Otter switch replaced. I suspect it's because the radiator and fans are rather tired and less efficient than they used to be.
I'm aware that fitting a new aluminium radiator is a well-tried mod and that's what I'd like to do, along with new fans. What is recommended by posters here? I've read about an impressive-sounding company called Coolex Heat Transfer in Nottingham. Does anyone here have any experience with them?
Thanks!
Andy
Agree with high output Spal fan - but high current therefore upgraded wiring to fan needed. Single large diam fan should do the trick though you would need a custom shroud. Recore of your radiator from the likes of Northern Radiators would cut your costs. Good luck and let us know how it goes.
Be aware aluminum radiators are not more efficient, they're just lighter, the most efficient material to construct a radiator core from is copper, no question! A traditional copper core radiator will outperform an aluminum one of the same capacity every time, this is because aluminum is a metal that can only conduct heat roughly half as well as copper.
Aluminum will lose 118 BTU/(hr·ft/°F) while copper lets go of 223 BTU/(hr·ft/°F), this is why radiator cores have been made from copper since the dawn of time, copper is an excellent conductor of heat so makes the perfect choice for all types of heat exchangers, heat sinks, and even saucepan bottoms. Aluminum is also prone to fatigue cracking especially around welds, while aluminum itself has a slightly lower melting point than brass, TiG welding aluminum develops an intense heat of approximately 11,000°F and when you apply such heat to aluminum (or any metal) you locally change it's molecular structure, this tends to make aluminum very brittle around the edges of welds which is why it can suffer cracks.... which are never a good thing in a pressurized radiator.
Obviously you braze brass rather than weld it, brazing is a more gentle and far lower temperature joining process than welding, when brazing you're not actually melting the base metal you're joining (as with welding), you're just melting a separate sacrificial brazing rod into the joint. The base metal only needs to be heated sufficiently for that melted rod to flow by capillary action into the gap and form a sealed joint.
Unlike the intense localised heat TiG welding inflicts on aluminum, brazed brass stays massively cooler, so not only is brass way more flexible and less crack prone in the first place, because the heat needed to join it is so much lower the molecular change you get with all metals when you heat them (causing embrittlement) is no longer an issue. A TVR has a separate chassis with a separate body bolted to it, movement and vibration are the inevitable consequences of this type of construction, a traditional brass tanked copper core radiator will not only cool better than an aluminum one of the same capacity it will also tolerate a lot more vibration and movement before fatigue cracking.
Clearly if you build an aluminum radiator with a bigger core it will outperform a standard brass tanked copper core radiator, but this is not comparing apples with apples. If you just get an extra core/row put in your original brass/copper radiator when you have it reconditioned it will outperform the uprated aluminum one, it will admittedly be heavier, but as well as being more efficient it will also be more durable and last longer. These are the facts about radiators, aluminum radiators are lighter and race car sexy, but that definitely doesn't make them superior to a traditional copper cored and brass tanked original. My advice would be to get your original rebuilt by a proper old school radiator reconditioner, it's not strictly essential but ask him to put an extra core in it for you and you'll never have any overheating issues.
If the fans are the same as fitted to the Chimaera, you could also replace them for 2 x Spal VA10-AP70/LL-61A, these are £131.95 each purchased direct from Spal UK. However, before you treat your TVR to new fans you should go right through how they are wired paying particular attention to the quality and cleanliness of their earthing points. TVR were notorious for using wiring of an insufficient gauge and it's no secret the cars suffer from poor earths, add in 20 years or so of earth point corrosion and general age related wiring degradation and you may find you can achieve as much as 25% more efficiency from your current fan setup just by upgrading the wiring and or cleaning up the earths.
Aluminum will lose 118 BTU/(hr·ft/°F) while copper lets go of 223 BTU/(hr·ft/°F), this is why radiator cores have been made from copper since the dawn of time, copper is an excellent conductor of heat so makes the perfect choice for all types of heat exchangers, heat sinks, and even saucepan bottoms. Aluminum is also prone to fatigue cracking especially around welds, while aluminum itself has a slightly lower melting point than brass, TiG welding aluminum develops an intense heat of approximately 11,000°F and when you apply such heat to aluminum (or any metal) you locally change it's molecular structure, this tends to make aluminum very brittle around the edges of welds which is why it can suffer cracks.... which are never a good thing in a pressurized radiator.
Obviously you braze brass rather than weld it, brazing is a more gentle and far lower temperature joining process than welding, when brazing you're not actually melting the base metal you're joining (as with welding), you're just melting a separate sacrificial brazing rod into the joint. The base metal only needs to be heated sufficiently for that melted rod to flow by capillary action into the gap and form a sealed joint.
Unlike the intense localised heat TiG welding inflicts on aluminum, brazed brass stays massively cooler, so not only is brass way more flexible and less crack prone in the first place, because the heat needed to join it is so much lower the molecular change you get with all metals when you heat them (causing embrittlement) is no longer an issue. A TVR has a separate chassis with a separate body bolted to it, movement and vibration are the inevitable consequences of this type of construction, a traditional brass tanked copper core radiator will not only cool better than an aluminum one of the same capacity it will also tolerate a lot more vibration and movement before fatigue cracking.
Clearly if you build an aluminum radiator with a bigger core it will outperform a standard brass tanked copper core radiator, but this is not comparing apples with apples. If you just get an extra core/row put in your original brass/copper radiator when you have it reconditioned it will outperform the uprated aluminum one, it will admittedly be heavier, but as well as being more efficient it will also be more durable and last longer. These are the facts about radiators, aluminum radiators are lighter and race car sexy, but that definitely doesn't make them superior to a traditional copper cored and brass tanked original. My advice would be to get your original rebuilt by a proper old school radiator reconditioner, it's not strictly essential but ask him to put an extra core in it for you and you'll never have any overheating issues.
If the fans are the same as fitted to the Chimaera, you could also replace them for 2 x Spal VA10-AP70/LL-61A, these are £131.95 each purchased direct from Spal UK. However, before you treat your TVR to new fans you should go right through how they are wired paying particular attention to the quality and cleanliness of their earthing points. TVR were notorious for using wiring of an insufficient gauge and it's no secret the cars suffer from poor earths, add in 20 years or so of earth point corrosion and general age related wiring degradation and you may find you can achieve as much as 25% more efficiency from your current fan setup just by upgrading the wiring and or cleaning up the earths.
Thanks guys for great info - tips and technical background - a lot that I didn't know.
This is part of the works to be done alongside the yearly service in the next few weeks, in readiness for hopefully plenty of driving in 2018. I took it out yesterday for the first time this year to blow out the cobwebs - the car's and mine! But keeping a beady eye on the temp gauge...
It's got 37,000 miles on it and it's tremendous fun. Last year I did about 5,000 miles, including a trip to mid-France with my girlfriend - she loves it! Plenty of trips locally and into Wales. I live in a small village on the Welsh borders and a few fellow inhabitants became first-time Griffith passengers in 2017 - big smiles every time! Roads are tremendous in these parts; come on over some time if you haven't already!
I'll keep you posted on progress with the radiator. Enjoying the forum and thanks again for the responses.
This is part of the works to be done alongside the yearly service in the next few weeks, in readiness for hopefully plenty of driving in 2018. I took it out yesterday for the first time this year to blow out the cobwebs - the car's and mine! But keeping a beady eye on the temp gauge...
It's got 37,000 miles on it and it's tremendous fun. Last year I did about 5,000 miles, including a trip to mid-France with my girlfriend - she loves it! Plenty of trips locally and into Wales. I live in a small village on the Welsh borders and a few fellow inhabitants became first-time Griffith passengers in 2017 - big smiles every time! Roads are tremendous in these parts; come on over some time if you haven't already!
I'll keep you posted on progress with the radiator. Enjoying the forum and thanks again for the responses.
I’m not sure of the Griff but in the Chim the rad is suspended away from the bodywork on rubber bobbins ( Mini exhaust ones) and located with two lugs that sit in pre formed holes at the bottom of the body. Mine have plenty of clearance to move ( not that is does ) and stress on my alloy rad is non existent as far as I can see.
It’s now 6 years old and touch wood in as new condition. It’s a lot lighter than the original one and as it’s a sportscar something I like a lot.
It’s very efficient too. I like it very much.
Importantly I got it from Powers Performance, it fits properly and I’m sure was made in Coventry and Coventry has a long history for making radiators going way back.
It’s a quality piece of kit
It’s now 6 years old and touch wood in as new condition. It’s a lot lighter than the original one and as it’s a sportscar something I like a lot.
It’s very efficient too. I like it very much.
Importantly I got it from Powers Performance, it fits properly and I’m sure was made in Coventry and Coventry has a long history for making radiators going way back.
It’s a quality piece of kit
It needs to be stronger as it’s so much heavier 
Alloy roads are used in many cars.
Why does a rad need to be so strong.
If it’s suspended properly it should not take torsional forces or vibration.
The lighter it is the less forces are applied surely.
Each to their own I say.
I’ll agree it’s not as strong as a metal one but honestly don’t understand why it needs to be so strong in the first place if it’s suspended properly.
The original rads are very efficient so def worth considering a recore
Alloy roads are used in many cars.
Why does a rad need to be so strong.
If it’s suspended properly it should not take torsional forces or vibration.
The lighter it is the less forces are applied surely.
Each to their own I say.
I’ll agree it’s not as strong as a metal one but honestly don’t understand why it needs to be so strong in the first place if it’s suspended properly.
The original rads are very efficient so def worth considering a recore
I would recommend going for a re-core of the existing copper rad. Unless you are looking to race your Griff then the slight extra weight of copper will make no difference. Even when properly mounted the rad will flex as it is only mounted onto the plastic body. Copper beats ally for heat transfer and is better suited to the probability of flex from the fibreglass mounting. There are some excellent recore firms out there and they will be able to add extra cores to the rad matrix as well if you want extra cooling.
Mike
Mike
Kitwa said:
Thanks again for all the advice - looks like a re-core is going to be the way to go. Yonex: I have emailed you for the contact - thanks!
I have tried to upload a couple of pics of the car - hope it's worked!
![](https://thumbsnap.com/sc/BCUmEcK1.jpg[/img]</a> <a href="https://thumbsnap.com/DwmDDt7l" Target="_blank" rel="nofollow">[img]https://thumbsnap.com/sc/DwmDDt7l.jpg)
Nice car I have tried to upload a couple of pics of the car - hope it's worked!
Your profile says Welsh Marches, obviously this is a big area, but if you're close to Hereford these people look like a proper traditional radiator reconditioning outfit.....
http://www.herefordradiators.com/home.html
Re cooling fans, my late 500 has twin fans and when they cut in the idle drops noticably and i dont know if its my imagination, but i cant help thinking that the power drops as well ?? They seem to take a huge amount of power from the electrical system. Both the alternator and bartery are recent replacements.
Any ideas anyone ?
Any ideas anyone ?
The idle will drop when the fans start due to the alternator load. The stepper motor should compensate and allow the idle to return to its normal level.
With the fans running with the car on the move, there will still be the alternator load on the engine, which will reduce the power going to the wheels fractionally, but I would be amazed if you could feel or notice the difference.
With the fans running with the car on the move, there will still be the alternator load on the engine, which will reduce the power going to the wheels fractionally, but I would be amazed if you could feel or notice the difference.
neutral 3 said:
Re cooling fans, my late 500 has twin fans and when they cut in the idle drops noticably and i dont know if its my imagination, but i cant help thinking that the power drops as well ?? They seem to take a huge amount of power from the electrical system. Both the alternator and bartery are recent replacements.
Any ideas anyone ?
I can’t say my idle drops that much. A little maybe. If they were drawing lots of current the fuse would fail? Check the wiring to make sure it’s all solid then clamp the fans just in case?Any ideas anyone ?
Kitwa said:
I'm the owner of a '92 4.3 big-valve Griffith and new to posting on the site; any advice gratefully received.
I got the car summer before last, and it's been tremendous. I'd fancied one for some time and it's really exceeded expectations.
It does run rather hot, in spite of having been checked over by Team Central and having the Otter switch replaced. I suspect it's because the radiator and fans are rather tired and less efficient than they used to be.
I'm aware that fitting a new aluminium radiator is a well-tried mod and that's what I'd like to do, along with new fans. What is recommended by posters here? I've read about an impressive-sounding company called Coolex Heat Transfer in Nottingham. Does anyone here have any experience with them?
Thanks!
Andy
Have you had a thermal check of the coolant temperature, because I bought a car off a guy last year who had a similar problem. He replaced the radiator, water pump and finally found out that the GAUGE was reading HIGH!I got the car summer before last, and it's been tremendous. I'd fancied one for some time and it's really exceeded expectations.
It does run rather hot, in spite of having been checked over by Team Central and having the Otter switch replaced. I suspect it's because the radiator and fans are rather tired and less efficient than they used to be.
I'm aware that fitting a new aluminium radiator is a well-tried mod and that's what I'd like to do, along with new fans. What is recommended by posters here? I've read about an impressive-sounding company called Coolex Heat Transfer in Nottingham. Does anyone here have any experience with them?
Thanks!
Andy
Cost the bloke a packet.
yonex said:
neutral 3 said:
Re cooling fans, my late 500 has twin fans and when they cut in the idle drops noticably and i dont know if its my imagination, but i cant help thinking that the power drops as well ?? They seem to take a huge amount of power from the electrical system. Both the alternator and bartery are recent replacements.
Any ideas anyone ?
I can’t say my idle drops that much. A little maybe. If they were drawing lots of current the fuse would fail? Check the wiring to make sure it’s all solid then clamp the fans just in case?Any ideas anyone ?
New additional chunky earth back to the original chassis earth point (under whaletail), plus a half-hearted attempt at cleaning the fan supply connections near the rad and the reduction in drop in idle is considerable.
Might be worth checking/cleaning earths.
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