45 replies to this topic

[Pops_Guild]

It looks like my original radiator in my SPI Cooper (standard apart from an LCB) is passed it's best. Despite doing all the flush-through, and recommended things, I'm still getting overheating problems. 

 

So I'm after a bit of advice, I want it keep the original look of the rad but it would seem to make sense to get an upgrade too..looks like I can buy original spec replacement, or possibly 2, 3 or 4-core. Not sure what makes most sense or is best?

 

Thx

 

 

[DeadSquare]

How clean are the fins ?

 

Oily fumes and dead flies can add up to a lot of restricted air flow.

 

I once read about tests on air conditioners, and while adding more cores seems the way to go, heat transfer is what it is all about, and less air trying to pass 4 cores isn't that much better than a lot of air easily passing 2 cores.

 

I'd blow through the fins with an air line, then make a plastic lined tray and soak your rad in paraffin for 24 hours and blow it through again.  You might have to repeat another 24 hours, but I have found this better than a 5 minute pressure washer.

 

On my supercharged Minis, I found that the standard 3 core was OK with an additional electric fan in the wing.

[unburntfuelinthemorning]

If you think the radiator is past its best and the engine is mostly standard then a standard replacement radiator should suffice:  http://www.minispare...px|Back to shop

 

What sort of overheating problems are you getting?

[expat_cat]

If you can push the extra cost, go for one of minispares 2-core offerings (C-ARA4443 or 4442).

 

For me (also in an SPI) copes with driving in traffic with ambients over 35C, and they are just that much thinner, which helps when fitting it in!

[Curley]

I'll vote for the RadTec units as sold direct or via minispares: http://www.minispare...41.aspx|Back to

[Pops_Guild]

How clean are the fins ?

 

Oily fumes and dead flies can add up to a lot of restricted air flow.

 

I once read about tests on air conditioners, and while adding more cores seems the way to go, heat transfer is what it is all about, and less air trying to pass 4 cores isn't that much better than a lot of air easily passing 2 cores.

 

I'd blow through the fins with an air line, then make a plastic lined tray and soak your rad in paraffin for 24 hours and blow it through again.  You might have to repeat another 24 hours, but I have found this better than a 5 minute pressure washer.

 

On my supercharged Minis, I found that the standard 3 core was OK with an additional electric fan in the wing.

 

Thanks! The fins are clean. I degreased, hot washed, blew through etc. As mentioned I did a bunch of flush through work with and without cleaners.

 

I may also have a problem with the aux elec fan not coming on when it should. I'm investigating that this weekend but the switch/sensor is brand new so in theory that should be fine but regardless I'll make sure that is working before I go splashing out on a new rad.

 

...but I may still have to go down the new rad route anyway.

Edited by Pops_Guild, 15 May 2019 - 12:37 PM.

[Pops_Guild]

If you think the radiator is past its best and the engine is mostly standard then a standard replacement radiator should suffice:  http://www.minispare...px|Back to shop

 

What sort of overheating problems are you getting?

 

Thx. Yeah, logic says to me that a standard rad should be man-enough especially if everything else is up to scratch. I have no plans to modify the engine.

 

After 3 1/2 years of complete restoration we drove the Mini from Norfolk to Guildford at the weekend, it overheated about an hour into the journey as we hit the dual carriageway of the A11. It seems like cruising at anything over 65mph caused it to heat up significantly and after a few spirited overtakes it overheated (boiled over, crap all over the rhs of the engine bay). As noted in one of my earlier replies I did notice the aux fan didn't come on/wasn't on...that could be 100% the reason for the overheat but it might not have been helped by the old rad. It might be a symptom of something else?

 

AA man came out, ran checks, it behaved perfectly. We drove the remaining 90 miles keeping it under 65mph with no more issues.

 

Aside from a adding LCB and the engine getting a stringent service and clean up and cleaning up all the water-ways, new piping etc, its bog standard block and gearbox. Pretty much everything else mechanical outside of the engine on the mini is new/replaced. It passed MOT clean as a whistle for ever that means.

 

I've owned enough Mini's to know overheating is a thing they do and that is why I spent effort making sure all the waterways were cleaned up or new in the restoration, everything except the rad that is, which I completely cleaned...or so I thought

[Pops_Guild]

If you can push the extra cost, go for one of minispares 2-core offerings (C-ARA4443 or 4442).

 

For me (also in an SPI) copes with driving in traffic with ambients over 35C, and they are just that much thinner, which helps when fitting it in!

 

 

thanks the 4443 is the one I was thinking, just didn't know if it really makes a difference over the standard rad. It sounds like it does. It is important to keep the bay looking as original as possible too so that looks to be a close visual match to the original? Is that the case?

[Pops_Guild]

I'll vote for the RadTec units as sold direct or via minispares: http://www.minispare...41.aspx|Back to

 

 

Thanks, I've heard they're good but it looks too different from the original for me. Maybe I'm daft thinking that way but I do want to keep things as standard as poss.

[unburntfuelinthemorning]

 

As noted in one of my earlier replies I did notice the aux fan didn't come on/wasn't on...that could be 100% the reason for the overheat but it might not have been helped by the old rad. It might be a symptom of something else?

 

I've owned enough Mini's to know overheating is a thing they do and that is why I spent effort making sure all the waterways were cleaned up or new in the restoration, everything except the rad that is, which I completely cleaned...or so I thought

 

If it was overheating in slow moving traffic you could blame the fan but the engine driven fan is hurling loads of air through the radiator at 65 mph. 

 

Is the thermostat opening fully?  Is the radiator cap the correct rating and is it working properly?

[unburntfuelinthemorning]

 

thanks the 4443 is the one I was thinking, just didn't know if it really makes a difference over the standard rad. It sounds like it does. It is important to keep the bay looking as original as possible too so that looks to be a close visual match to the original? Is that the case?

 

The Minispares uprated radiators do work well and look virtually original.

[slidehammer]

I agree, a standard good quality (Mini Spares) replacement radiator should be fine. Especially as the engine is pretty well stock.

[luismx123]

You could look at a fletcher 2core from huddersfield. I got one for my mini this year and so far havnt had any issue driving for approx. 40min at 65+mph on the highway at 30*C outside temps. Its a 998 wth a stage 1 kit so nothing amazing
There is a theory about black vs shiny radiators, dont quote me on it but I think a black painted surface cools better than a reflective/shiny one. I went with the fletcher because it was 120 pound with silicon pipes and seen quite a few around. Looks really neat too :)
I think a 2 core is better than the original ones, but theres a thread floating around here. One is better for slow moving traffic, and there is not much difference at speed. Ill see what I can find later on today. :) 

Edited by luismx123, 15 May 2019 - 01:47 PM.

[unburntfuelinthemorning]

There is a theory about black vs shiny radiators, dont quote me on it but I think a black painted surface cools better than a reflective/shiny one.

Black absorbs and radiates heat better but then you're adding a layer of paint which has the opposite effect. 

[DeadSquare]

 

There is a theory about black vs shiny radiators, dont quote me on it but I think a black painted surface cools better than a reflective/shiny one.

Black absorbs and radiates heat better but then you're adding a layer of paint which has the opposite effect. 

 

 

 

The copper radiator should not be painted.

 

By dipping the bright copper in the correct solution, a micron thick layer of black copper oxide is formed on the surface.  (O level chemistry)