K Series ally radiators

[Foggy]

Hi all, 

my 22 year old k series rad is showing signs of having had enough so I'm going to use the opportunity to upgrade to a nice shiny aluminum one.  Roadsport 1800, road use only, just high days and holiday use (eventually!) so with that in mind I've been looking at Radtec, Alicool and Coolexperts.  Any recommendations for (or against)?

Thanks in advance 

[TomB]

Im thinking about this too.  Ideally Id be able to keep my existing fan and switch.

Buying direct, prices seem to be very similar between the suppliers.  Radtec a bit more expensive but they offer a 10% club discount which brings each of them to around £220+vat.  Core thicknesses seem to vary slightly between suppliers.   

If your looking at buying during lockdown, I don't think Radtec are dispatching orders at the moment, but I don't know about the others. 

Redline can supply both original CC and Radtec radiators and have stock, but I think they're price is higher than buying direct.

   

[7 wonders of the world]

Alicool is the place to go  

[TomB]

Why? Is it quality, price, service, performance?  Looking at images on line, they all look remarkable similar to my untrained eye.  

[Foggy]

I have to agree with TomB and that is precisely what prompted the post in the first place. Are they all much the same or is there a technical element we should be aware of?  I noted that Coolexperts are offering a 2 year guarantee if that's anything to go by.

 

[Orange]

I recently fitted a Radtec one and I am very pleased with it. I ordered a new 11inch fan and switch. I can't comment on the other manufactures but the Radtec were very helpful when I phoned to order just before the lockdown. This was fitted part to reduce running temperature and part because I wanted a shiny new radiator (since discovered higher running temperature was caused by a faulty thermostat) I do have my old radiator available in the for sale section.

[TomB]

Looking again, Radtec and Alicool seem to be very similar design, with tanks to the side of the radiator and temp switches in similar locations.  There is a slight difference in the fan mounting brackets, but other wise they look the same.  The Alicool has a 45mm core and the Radtec 50mm core. 

The Coolex one seems most like the Caterham standard radiator, with tanks on the top and bottom, albeit made of metal not plastic.  It also has an additional bleed point in the top tank which I would need to blank off.   I'd rather not have a hole that needs blanking as its just another point for air ingress.  

 

[StevehS3]

I have been pondering on the same. My CC rad has/had a slight weep from the crimps onto the plastic top. It doesn't look very well engineered. But, my concerns with the others are (i) do they upset the cooling circuit arrangement ie over-cool; and (ii) are they damaged by the pink OAT coolant that is the recommendation for the engine. Hmm...

[Blue C7]

Radtec recommend blue antifreeze

[Orange]

The Radtec one has a single bleed screw on the top corner and a drain screw on the diagonally opposite corner (useful and much cleaner way to drain when you need to then change the thermostat, saves disturbing pipes) 

I have used the pink coolant as I figure the engine is made of aluminium so should be ok, that and a radiator is cheaper to replace than an engine.

The Radtec does not over cool, my car now stays a very steady 85ish and only raises slightly when sat before the thermostat opens/ fan kicks in to cool everything down.

[John Vine]

Radtec recommend blue antifreeze

Do you know if they suggest a particular brand or a specific inhibitor package?  IAT versus OAT, for example?

JV

[Foggy]

Have to admit I'm coming down in favour of either Radtec or Alicool. My understanding is that Radtec offer a 12 month warranty, I assume Alicool will be the same, unless anyone knows differently? Is it me or does the weld quality look smoother in the Alicool and is 45mm v 50mm core going to be significant? 

[7 wonders of the world]

Alicool is run by a guy who used to work at Radtec and was dishartened by thenumber of returns due to failures of bought in parts from the Far East.

He uses better quality components and is happy to make amends to suit you requirements, he sometime pops a few on ebay too so you mat pick up a bargain if you after a stock version.

 

[Foggy]

Interesting, thanks for that. 

[JonT]

I had great customer service from radtec a couple of years ago - after fitting the rad discovered a tiny weep from one of the welds. They sent out a new rad immediately; I returned the old one expecting to hear nothing more, but a couple of days later another large package turned up. They'd fixed the weld and sent it back to me as a spare (I guess since it had been filled with coolant they couldn't resell it). But it hasn't been needed in the couple of years and 10k or so miles since.

No issues with overcooling or heating, whether in freezing temps at the top of Stelvio or second hottest day of last year on a track day at Clastres. I do have a laminova which will dump extra heat into the cooling system and my thermostat setup is non-standard though (1600 K-series).

 

[TomB]

Jon - if you want to sell your spare let me know. 

 

[JonT]

I went for the larger fan, so I suspect the brackets are different if you were planning to keep yours...

[Wrightpayne]

The old style copper cored ones have some value and can be re-cored. I took mine to a place in Coventry to be done.

As has been alluded to, I remember a phase on Blatchat a few years ago where there were several ali rad failures discussed. I seem to remember the mini bobbins were considered too rigid in some threads, causing failures. I believe more likely quality issues.

My copper one been fine on road and track for 22 years incl a double driver session at Cadwell. If I had the later ali with plastic headers I think I'd have changed it - again there were problems with these when first introduced IIRC.

[paul richards]

I can recommend Radtec for service. I had a 10? year old rad that started a small leak near the core. Expecting to have to purchase a new one I rang Radtec and they suggested it might repair. I sent it off with a request for an additional vent pipe to be fitted as well as the repair. They tested it, repaired it, modified it and replaced a broken fan bracket. I rang them as I was keen to have it back ready for an imminent trip. They said it was in test and they'd get it to me ASAP. It turned up the next day. Rang them to say thanks and expressed surprise that they had released it before payment. They'd done that because I was in a hurry. Best of all the cost was very modest - a fraction of the price of a new rad and yes it's still fine 6 years later. By the way I now use bluecol antifreeze on their recommendation.

[paul richards]

I can recommend Radtec for service. I had a 10? year old rad that started a small leak near the core. Expecting to have to purchase a new one I rang Radtec and they suggested it might repair. I sent it off with a request for an additional vent pipe to be fitted as well as the repair. They tested it, repaired it, modified it and replaced a broken fan bracket. I rang them as I was keen to have it back ready for an imminent trip. They said it was in test and they'd get it to me ASAP. It turned up the next day. Rang them to say thanks and expressed surprise that they had released it before payment. They'd done that because I was in a hurry. Best of all the cost was very modest - a fraction of the price of a new rad and yes it's still fine 6 years later. By the way I now use bluecol antifreeze on their recommendation.

[ECR]

I thought the following might be appropriate for this post. Original author acknowledged ....

Antifreeze

 

Antifreeze not only suppresses the freezing point of your engine coolant, but provides good corrosion protection and increases the boiling point during use.



Most commercial antifreeze formulations include a glycol (to suppress the freezing point and raise the boiling point), corrosion inhibiting compounds and a coloured dye (commonly orange, green, red, or blue fluorescent) to aid in identification. A 1:1 dilution with water is usually used, resulting in a freezing point in the range of minus 37 °C to minus 42 °C, depending on the formulation.



There are two basic types of coolant available today dependent on the corrosion inhibitors used:



·inorganic additive technology (IAT)

·organic additive technology (OAT)



Inorganic Additive Technology



This is the traditional coolant based on inorganic additives and is called inorganic additive technology (IAT). It is a tried and proven chemistry that provides a fast acting protective film. The additives deplete and the coolant needs to be drained and replenished every couple of years. This type can be used on all mixed metal engines with components including steel, cast iron, copper, brass, aluminium and solder without any detrimental effect.



Organic Acid Technology



The newer OAT coolants work differently from the older silicate based IAT coolants. Aluminium and ferrous metals form a surface-layer of corrosion in the presence of moisture, even with the little bit of moisture in the air.

OAT coolants prevent this metal-oxide layer that protects the surface against this corrosion.

 Inherent with their design, the OAT coolants last longer than the older traditional IAT coolants. This category of antifreeze cannot be used in systems containing yellow metals.



A couple of questions and answers.



Why are coolants different colours?



Coolants/antifreezes are coloured so you can visually see them; colour intensity can be an indication of over dilution. The different colours are non specific to the different types of antifreeze. The manufacturer can dye the product any colour they want. The colour is no guide to the actual type of antifreeze type and the label should be read before use.



What is best for performance use?



It is always best to use the engine manufacturer’s advice. If engine contains yellow metals [copper and brass as in older vehicles] then the long life products based on organic technology should not be used. As a general rule, most modern engines require the long life organic antifreezes.



Is there any advantage to using concentrate over pre-mixed coolants?



None other than the user may want to use the pre-mixed product due to ease of handling or cost and visa versa.



Can concentrate and pre-mixed coolants be mixed?



A simple answer is that you can, however do not mix IAT and OAT antifreeze together.



So, there we go. Hopefully this information has been useful, if you have any further questions not covered here please ask and I will try to get the answer.



With thanks to Martyn Mann and Millers Oils.

So the "yellow metals" situation seems to be the decider here. It may well be significant if you have added accessories to the cooling system that contain yellow metals ....

This from Bluecol

Bluecol 2 year blue antifreeze is a traditional methanol-free, Ethylene Glycol based antifreeze and engine coolant. Bluecol 2 year antifreeze can be kept in your radiator system all year round to maintain protection against winter freezing and summer overheating, whilst at the same time protecting the materials in the cooling system against rust and corrosion. Bluecol 2 year antifreeze is suitable for all cooling system metals, including aluminium and iron. It does not evaporate in use and is not flammable.

 

Bluecol 2 year blue antifreeze and engine coolant does not incorporate Organic Acid Technology (OAT) and is suitable for classic & vintage vehicles.

 

Bluecol 2 year antifreeze conforms to BS6580 (2010) and contains a bittering agent to prevent accidental swallowing and consequential harmful effects to humans and animals.

 

 

[gileshudson]

J&J Radiators methinks... they've been doing rads for a million years now.
Alan and Jo long gone, but Dave and sister keeping the business in the family

[Golf Juliet Tango]

Great post Roger, lots of detail & explanation from first hand source.

One just needs to identify what is in the system & copy that.

[Foggy]

Having had a chat with Darren at Radtec I've ordered a shiny new one!  Have to say, it was an absolute pleasure talking to the man and and his help and advice were both refreshing and welcome. Many thanks to all for their contribution to this post, appreciated 

[John Vine]

Re #21:

Thanks for that, Roger.

So the "yellow metals" situation seems to be the decider here. It may well be significant if you have added accessories to the cooling system that contain yellow metals ....

That's a very interesting point. 

Do we know what metals are in the standard heater and bypass valve? 

If you use an OAT coolant (such as Comma G30) on a Duratec or Sigma, presumably it would be unwise to replace, say, the plastic T-piece (connecting heater outlet, expansion bottle, and engine inlet) with a copper or brass alternative?

JV