21 replies to this topic

[Ethel]

Pretty much, 

 

A lower rated stat would mean you're starting from a lower place , with more spare capacity, when you hit that hill. But it won't take long to use it up if the hill's big enough. More heat in than heat out still equals trouble. 

 

 

A different stat might help with the combination of combustion chamber temperature & induction temperature to keep you on the right side of detonation though.

[Spider]

C, I'm running a four blade metal fan with a three core radiator, 194 degree 'stat.  Probably should install one rated at 180.  The engine has been bored out to 1360, using a BDK needle with the AFR adjusted on the rich side, low 13's at idle and low 14's at cruise.  Distributor has been modified by Ac Dodd and timed in a 10 degrees BTDC, vacuum advance disconnected. 

 

The cooling system on a mini has always been a puzzlement to me.  Blowing hot air from the engine compartment through the radiator seems backwards. 

 

I've found that the 4 blade fan is marginal. it doesn't have a lot of collective surface area and only a 'moderate' pitch on the blades. The fan I found that moves the most air is the 6 blade as Nick already mentioned. They are said to be noisy, maybe I'm going proper deaf ( not just selective !), but while I can hear mine, I really have to strain to do so, I find it not very noisy at all.

 

While it won't help with your running hot issue, I would suggest running a 180 F Thermostat. The factory only went to the hotter types to help meet emission standards.

 

The other item you might want to look for is a 4 tube (core) radiator. If you can find an old Leyland one and have that reconditioned, that'll end up better than the current new ones, or a Radiator from a ADO16, these fit right in on a Clubby front end and with some careful manipulation, will fit under a Round Nose. You'll need the cowling to go with this. I always found the 3 tube (core) Radiators 'marginal' at best. The slightly extra capacity of the 4 tube or ADO16 Radiator tips the system over the top of that heat exchange hill and gets them to behave.

 

It probably does seem odd to you how the air flow through the engine bay on these cars is. In a conventional north / south engined car, when on the move, with a front mounted radiator, there is an obvious air pressure differential across the radiator, giving air flow. This is how these cars can successful use things like electric and clutch fans that effectively 'turn off' when on the move, only being needed at slower speeds and at a stop. With the Mini and it's side mounted Radiator, there's little pressure differential between the Engine Bay and the Wheel Arch, as much of the little air entering through the grill goes under the engine, some will naturally go out through the wheel arch (and any other engine bay opening), but as the air pressure in the wheel arch isn't much lower than that in the Engine Bay, there's 2 fifths of bugger all air flow, so the fans on these cars are needed and work hard all the time. As you can well appreciate, a Radiator as a heat exchanger will work no matter which way the Air flows through it, as long as there is air flow. Since there is some (small) pressure difference between the engine bay and the wheel arch, the better way to move the air is in to the wheel arch, though I'm sure it would likely work almost as well blowing the other way.

This issue of natural pressure differential is better on a Mini than a Moke. As the Moke has a fairly open wheel arch and the front panelwork tapers away. I must test it one day, but I'm sure on these cars, the pressure is higher in the wheel arch than the engine bay. The wheel arch is well open to the air from the front and side, all one needs with these is for the wind to be blowing from the wrong direction and with a stock cooling system, you're in a world of trouble.
 

[Aria Aradhea]

 

The other item you might want to look for is a 4 tube (core) radiator. If you can find an old Leyland one and have that reconditioned, that'll end up better than the current new ones, or a Radiator from a ADO16, these fit right in on a Clubby front end and with some careful manipulation, will fit under a Round Nose. You'll need the cowling to go with this. I always found the 3 tube (core) Radiators 'marginal' at best. The slightly extra capacity of the 4 tube or ADO16 Radiator tips the system over the top of that heat exchange hill and gets them to behave.

 

 

This is interesting... what is the difference between the new 4-core radiators with those fitted on the ADO16? Will the new 4-core still be better than the standard 3-core? And what about 2-core radiators?

[Spider]

 

 

The other item you might want to look for is a 4 tube (core) radiator. If you can find an old Leyland one and have that reconditioned, that'll end up better than the current new ones, or a Radiator from a ADO16, these fit right in on a Clubby front end and with some careful manipulation, will fit under a Round Nose. You'll need the cowling to go with this. I always found the 3 tube (core) Radiators 'marginal' at best. The slightly extra capacity of the 4 tube or ADO16 Radiator tips the system over the top of that heat exchange hill and gets them to behave.

 

 

This is interesting... what is the difference between the new 4-core radiators with those fitted on the ADO16? Will the new 4-core still be better than the standard 3-core? And what about 2-core radiators?

 

 

Based on my own experience, I'd say the ADO16 (which is a 3 tube) Radiator would be slightly better than a Mini (ADO15 !) Sized 4 tube. I did actually forget to mention in my post ^ - there are 4 tube types and there's 4 tube types ! The last time I looked at the current ones, they are no better than a single tube type. The early types that were fitted in the 70's and 80's (and 90's ?) were proper 4 tube types that did make a big difference to how well they worked.

 

I did actually forget to mention in my post ^ - there are 4 tube types and there's 4 tube types ! The last time I looked at the current ones, they are no better than a single tube type. The early types that were fitted in the 70's and 80's (and 90's ?) were proper 4 tube types that did make a big difference to how well they worked.

 

The coolant will be better placed to dissipate heat by having the most possible surface area of the coolant in contact with the tubes in the radiator. If you really think about it, as the heat is removed from the coolant in the tubes, it's that thin part of the coolant which is in contact with the tube that the heat will be removed from with the central core of that but of coolant still retaining heat. Of course, as the outer 'layer' looses heat, it will draw heat from that central core. If the tube has too much cross sectional area or a poor shape (circular instead of a flat thin tube), then this situation is worse. So the more and thinner the tubes are the more efficiently it will dissipate heat. I've found attention to this detail can have a big impact on the cooling system and how well it works. My own Moke, I've driven (cruised) at a steady 100 kph in 53⁰ C ambient temps yet the coolant only got to around 93 - 95⁰ C. There is more to it than just this bit of detail, this is just one aspect.

 

If you look at the current new radiators, in the filler neck, you'll see the tubes are arranges such;-

 

 

Thinking about how the air flows through these, the way I see it, the tube right in front of the fan gets most of the air, with very little going around the other tubes. This seems why there's a perception that the '2 core' Radiators cool best. Not so.

 

The original 3 and 4 Tube types fitted to these cars from the factory, had staggered tubing arrangement;-

 

 

This alone makes a huge difference in how the radiator performs. The experience I referred to above (driving in 53 C temps), one of the other Mokes was fitted with a new 2 tube radiator. His ran much hotter to the point we had to slow down to let him Moke cool off.

 

I My last Radiator guy closed up shop a number of years ago and I've only just recent found a new guy who will do what I ask, not what he wants to sell. Iactually make some Radiator parts for him when he gets custom work in, but that's for another day.

Coming back to the question here (kind of), I haven't actually measured the ADO16 Radiator. It's a 3 Tube type (the originals being staggered), same height as a Mini one, but is about 2" wider (toward the front of the car), so fitting one is fairly easy. I believe these work so well due to the increase in tube surface area, while keeping the radiator 'thin'. With a 4 Tube type (of staggered tube arrangement), while definitely better than all other Mini Radiators, I believe that while it too has a big tube surface area, the down side of it is it is thicker than the 3 tube types, so as the air passes through it, it picks up more heat on it's way through and so the air passing over that last row, isn't as cool as it would be in a 3 tube type.

 

When hunting around for Cores of the staggered type, I found that while they are a standard product, no one stocked them, so I have them made to order (only takes a few days), however the in line tubes types are available off the shelf, I'm guessing here that these must be cheaper to make.

[Aria Aradhea]

Based on my own experience, I'd say the ADO16 (which is a 3 tube) Radiator would be slightly better than a Mini (ADO15 !) Sized 4 tube. I did actually forget to mention in my post ^ - there are 4 tube types and there's 4 tube types ! The last time I looked at the current ones, they are no better than a single tube type. The early types that were fitted in the 70's and 80's (and 90's ?) were proper 4 tube types that did make a big difference to how well they worked.

I did actually forget to mention in my post ^ - there are 4 tube types and there's 4 tube types ! The last time I looked at the current ones, they are no better than a single tube type. The early types that were fitted in the 70's and 80's (and 90's ?) were proper 4 tube types that did make a big difference to how well they worked.

The coolant will be better placed to dissipate heat by having the most possible surface area of the coolant in contact with the tubes in the radiator. If you really think about it, as the heat is removed from the coolant in the tubes, it's that thin part of the coolant which is in contact with the tube that the heat will be removed from with the central core of that but of coolant still retaining heat. Of course, as the outer 'layer' looses heat, it will draw heat from that central core. If the tube has too much cross sectional area or a poor shape (circular instead of a flat thin tube), then this situation is worse. So the more and thinner the tubes are the more efficiently it will dissipate heat. I've found attention to this detail can have a big impact on the cooling system and how well it works. My own Moke, I've driven (cruised) at a steady 100 kph in 53⁰ C ambient temps yet the coolant only got to around 93 - 95⁰ C. There is more to it than just this bit of detail, this is just one aspect.

If you look at the current new radiators, in the filler neck, you'll see the tubes are arranges such;-



Thinking about how the air flows through these, the way I see it, the tube right in front of the fan gets most of the air, with very little going around the other tubes. This seems why there's a perception that the '2 core' Radiators cool best. Not so.

The original 3 and 4 Tube types fitted to these cars from the factory, had staggered tubing arrangement;-



This alone makes a huge difference in how the radiator performs. The experience I referred to above (driving in 53 C temps), one of the other Mokes was fitted with a new 2 tube radiator. His ran much hotter to the point we had to slow down to let him Moke cool off.

I My last Radiator guy closed up shop a number of years ago and I've only just recent found a new guy who will do what I ask, not what he wants to sell. Iactually make some Radiator parts for him when he gets custom work in, but that's for another day.

Coming back to the question here (kind of), I haven't actually measured the ADO16 Radiator. It's a 3 Tube type (the originals being staggered), same height as a Mini one, but is about 2" wider (toward the front of the car), so fitting one is fairly easy. I believe these work so well due to the increase in tube surface area, while keeping the radiator 'thin'. With a 4 Tube type (of staggered tube arrangement), while definitely better than all other Mini Radiators, I believe that while it too has a big tube surface area, the down side of it is it is thicker than the 3 tube types, so as the air passes through it, it picks up more heat on it's way through and so the air passing over that last row, isn't as cool as it would be in a 3 tube type.

When hunting around for Cores of the staggered type, I found that while they are a standard product, no one stocked them, so I have them made to order (only takes a few days), however the in line tubes types are available off the shelf, I'm guessing here that these must be cheaper to make.

I see... Thank you for the explanation.

I agree with you that the parallel tube arrangements is not really good. My Mini was fitted with those type (and it's a standard 3 core) and I encounter overheating issues when I drive with the aircon on. Replacing them with a second-hand, original staggered type tube improved the condition massively. No more overheating issues.

Wish the Mini spares suppliers could provide information on the type of inner tubes of their products

[croc7]

Thanks all for the input. After digesting the information, I’m not so sure I actually had a cooling issue. What I had was a combination of high ambient temperatures and long climbs over mountain passes that made the car run hotter than usual. The helicopter pilot in me tends to worry over anything that isn’t normal.🤔

So the search for a mini radiator with three offset tubes begins. If for no other reason to see if any still exist.

[imack]

ADO16 rad is not only around 2" wider than a mini rad it's also around 2" deeper, I ran one in my mini from the late 80's until recently when it started leaking and I couldn't find anyone fairly locally to repair it. I'd had my ADO16 rad re-cored in the 80's by a local rad specialist who fitted a supposedly more efficient 'modern 3 core replacement, it was excellent, never had any cooling issues.
Had to replace it a couple of years ago with a radtech alloy rad, it seems more marginal than the old ADO16 unit.
Somewhere I have a pic of mini and ADO16 rads together, I'll try and find it.

OK, found the ADO16 vs alloy Radtech mini rad for size comparison, the core clearly isn't 2" taller as I remembered

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Edited by imack, 27 June 2021 - 09:09 AM.