19 replies to this topic

[zero_wlv]

Hi everyone,   a couple of years ago I posted a query about overheating  (the temp gauge had a habit of invariably creeping past 100C pretty much under any circumstances.    I think after a couple of years of trying everything under the sun  (engine filled with white vinegar for 7 days,  new rad,  new pump,  various new gaskets, new gauge, new 82C thermostat)   I've more or less finally solved it by simply fitting a wide fan spacer to bring the fan 8mm further into the cowl/duct on the rad.      I still have some more testing to do but it definitely did far better on an hour's run yesterday than it's been for a long time,   staying at 92C-95C and not rising above that.   No problems with town driving,  no problems with short waits at lights,   no problems with 60mph on an A-road.     (All temps are measured with an electric TIM gauge which seems to be quite accurate).    Admittedly ambient temp outside was quite low at 17C.

 

I say I've more or less solved it,   because on three occasions I 'simulated' a traffic jam by pulling over and letting it idle for several minutes.     Each time,  the gauge had risen to 100-102C within three or four minutes.   So there's evidently still an issue with airflow when stationary.

 

Anyway,   to get to the point,     does anyone else think the aftermarket wheel arch liners might cause an issue with air flow for the rad?      You can see from the pic that well over 50% of air discharged by my rad would end up over the TOP of the liner.       I imagine this could be less of a problem on the move  (air pressure in the wheel arches is presumably slightly negative (?) - the Bernoulli effect)  but at a standstill it's difficult to believe that hot air finds an easy way out.

 

Any thoughts?    Aftermarket liners are so popular I'd have thought someone else would have come across this problem if there actually is one,    but I can't find any discussion of it on the forum. 

 

 

Attached Files

•  20230715_202704.jpeg   64.32K   3 downloads

[sonscar]

I would not be happy with that myself,but what do I know?Will it not pressurise the top half and stall airflow?Steve..

[zero_wlv]

I would not be happy with that myself,but what do I know?Will it not pressurise the top half and stall airflow?Steve..

 

I'd be tempted to think the same,   except that there are so many recommendations for wheel liners on this forum that I would assume no-one else has experienced a similar problem with them,  and I'm barking up the wrong tree.

[mab01uk]

Some photos in this old thread showing the plastic arch liner cut around the electric fan fitted in the wheel arch of later Minis.

https://www.theminif...ners/?p=1747387

 

I found fitting the later Rover Mini electric fan to my Mini wired to a switch on the dash means I can switch it on in stationary traffic if the temperature gauge rises.

Although I got mine a lot cheaper secondhand at a Mini show:-

http://www.minispare...c/PGG10058.aspx

 

Edited by mab01uk, 23 July 2023 - 07:23 PM.

[68+86auto]

You don't mention any tuning such as fuel mixture or ignition timing. If these are out then you will never get it to run cool, tuning is the first thing to check. Only mess with the cooling system once it is confirmed using test equipment that there are zero issues with the ignition and fuel systems, not just "it runs well enough"

[zero_wlv]

It was set up on a rolling road session by someone quite experienced with BL cars back in November 2022,   mostly because I was hoping this might solve the problem.

I asked him to be conservative with the tuning as I'd had problems with it running hot.

It made no difference though  (I think he said it wasn't far out beforehand).

 

The engine itself though is a mildly tuned slightly overbored 998 with 1275 head and 266 cam.     Great engine but I often find myself thinking I should have stuck with a plain unadulterated 998 back when I had to replace my original engine!    I'm sure it'd have been far less hassle!

[gazza82]

Can you not remove the arch liner and see if there is any improvement? That way you can rule that out if it still overheats.

[roblightbody]

Hi,

 

I got Somerford to fit wheelarch liners to my Mini it in 2014, and I thought they looked like they'd cause havoc with the cooling similar to yours, but it only actually caused a problem on a hot French motorway when it would start to climb if I went fast.

 

After that I fitted one of these https://www.minispar.../C-ARA4443.aspx and it has never done it again,   Temp gauge never budges no matter what I do, and thats been over 8 years now.

 

Terrible photo attached taken from the wheelarch.

 

So my question is - what sort of radiator do you have? 

Attached Files

•  PXL_20230724_090521187.MP (Medium).jpg   54.94K   1 downloads

Edited by roblightbody, 24 July 2023 - 09:10 AM.

[zero_wlv]

@roblightbody   Hi Rob,  I have exactly the same radiator as yours,   C-ARA4443,   I fitted it last summer in an attempt to solve the problem,   with me it didn't make a noticeable difference so there must be something more fundamental at play.

 

As mentioned,  I'm feeling optimistic that I've finally solved the overheating problem on the move (although I need to test it some more,  I only went for a 1 hour drive on a coolish evening).

 

As gazza82 suggests,   I suppose my next step should be to remove the arch liner on that side and see if it makes a difference,   that'll at least help with diagnosis.

Luckily I didn't attach it with rivets as suggested by the instructions it came with!

 

Obviously I'd prefer not to remove the liner permanently as I don't want to end up with expensive rust repairs to the scuttle and wing.

Edited by zero_wlv, 24 July 2023 - 01:29 PM.

[stuart bowes]

I was thinking possibly a modification to the liner such that it still protects the bulkhead / rear half of the wheel area, but allows air flow at the front end

 

that is, if removal testing proves to make a noticeable difference 

 

presumably most of the mud flinging happens at the back side anyway, unless you do a lot of high speed reversing

Edited by stuart bowes, 24 July 2023 - 02:50 PM.

[IronmanG]

Just fit this with the rubber band

https://www.minispar...|Back to search

[MinesRed]

Is the fan on the correct way round?

[GraemeC]

I really doubt the liner will make much difference in a stationary situation.  They are far from sealed and the hot air will get pushed out  - you're not pressurizing a sealed volume.  I'd argue that using the cowl and the rubber bamd as recommended above may actually make it worse.  However an electric fan (either manual or automatic) would be a benefit and the liner could be cur around it.

 

I'd also say that 100deg when sat in traffic isn't excessive. 120+ degree and I'd be more worried, as long as the rad cap can hold the pressure then I wouldn't be too concerned.

 

If you could modify the liner to only cover the rear half then that might be a solution, however make sure it is a reasonably good fit so nothing can easily pass it (but ensure it can also drain!).  Mud, water and debris gets sprayed right around under the wing, not just the rear - that's why Minis also tend to rot on the seams below the headlight.

[IronmanG]

. I'd argue that using the cowl and the rubber bamd as recommended above may actually make it worse.

How?

[IronmanG]

. I'd argue that using the cowl and the rubber bamd as recommended above may actually make it worse.

How?