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MG MGA - Oil cooler

Hi
I certainly didnt want to hijack the "wheres my oil gone" thread, but was hoping for some advice please, on oil coolers.
On hot days, my temperature rises quickly in traffic jams. Its fine, when moving.
So I have bought the seven blade plastic fan that Steve kindly posted about and brought to my attention (thanks Steve). While I'm about it, I have also bought a fan shroud, to help pull the air through. Everyone seems to say they help in slow traffic.
I have an aftermarket oil cooler mounted about 80mm in front of the rad, and it appears that the oil cooler (and its rubber pipe work) might restrict flow to just over a quarter of the face of the radiator.

So my plan was going to be, at the same time as fitting the fan and shroud, to move the oil cooler to underneath. I wasnt planning to cut a hole in the front vallance. I reckoned that for my light use, an oil cooler is probably not really necessary, so any air it gathers from turbulence down below will be a bonus.

My question please - Am I right in thinking that moving the oil cooler out of the way of the rad, will help? I have just read a safety-fast article that suggested an air cooler will reduce coolant temperature by 20 dF, but had previously though that wasnt the case at all.(http://www.mgcc.co.uk/mga-register/wp-content/uploads/sites/22/2013/09/Fitting-an-oil-cooler.pdf)

So oil cooler in fromt of rad or down below for a light use road car?

Many thanks, Graham

PS I know I ought to have an original cell type rad, but in my ignorance had mine recored with modern fins only last year. So will need to defer any changes to rad in meantime
Graham V

Overheating when the car is moving implies inadequate radiator capacity; for the sake of the argument you can include the oil cooler in this.

On the other hand overheating when stationary, if the car doesn't overheat at speed, implies inadequate air flow.

If your car runs cool but gets hot stationary fitting an oil cooler will not improve the overheating, especially if you fit the cooler underneath where there is no airflow when stationary. Moving it probably won't improve your stationary cooling as even if it does block some of the radiator it's still in the fan's air path and will cool the oil. It's all about heat dissipation and it doesn't matter, with your current setup, whether the heat comes out of the radiator or the oil cooler.

What you need to do is improve your air flow. A fan shroud will help, but fitting a modern high flow electric fan in front of the radiator to push air through will be a better solution.

The setup I have is standard fan, with an additional manual 10" electric fan in front of the radiator.

I have an oil cooler mounted underneath. This is for additional cooling with hard running. I have not needed to put holes in the valance as there seems to be plenty of air flow under there while moving. This system seems to work as the car won't overheat with hard driving even when it's very hot (100F) here.

At present I have the fan very simply wired. I used the yellow/red wire in the loom that is for the optional fog lights. At this stage I haven't used a relay and the fan I am using seems to have a low enough current draw for this wiring. I have a 10A fuse in line. If I run into strife I'll wire it directly from the power to the starter and use a realy setup, still using the yellow/red wire for switching.


A Bowie

Like yours, my car will overheat if stationary in traffic when the weather is hot.

With this setup, all I do is manually switch the fan on if I'm in traffic. Once I'm moving again I switch it off. In the future I may fit a thermostatic controller but at present my system seems to work well.
A Bowie

Graham
I fitted my oil cooler underneath the radiator duct but I did cut a vent into the front valance to provide airflow to it. I placed it there to both cool the oil and also to make sure that the heat it removed exhausted beneath the car instead of passing back into the engine through the radiator.
I also fitted a thermostatic valve which only allows the oil through the cooler when it reaches 185 degrees to prevent over cooling the oil.


It did reduce my cars running temperature by about 5 degrees.
I had a large plastic fan which worked really well but it was noisy at high revs and I have since removed the engine fan and use twin electric fans instead which seem to work really well even with my 1950cc engine.
let me know if you would like any more info on my set up.
cheers
Colyn
Colyn Firth

Graham

I don't want to divert the thread away from your title, however, I think the issue rests with your poor cooling radiator. You are now going down the sticking plaster route instead of going for the open heart surgery. In my opinion you should get the radiator correctly cored. Perhaps speak to Bob West about an exchange unit. You already have the greater flow fan. This will give you more than enough airflow for the oil cooler in its present position and no need for the sticking plaster shroud nor electric fan.

I said it in the other thread that my 1800 with an asymmetric fan and original core radiator is giving me 170 to 173 in winter, rising only a few degrees to a solid 175 in the recent 24 to 26 temps.

Steve
Steve Gyles

Graham,
looking at my reply to your post, I think I only gave half an answer to it.

I think Steve is probably right, my radiator has the original design core too and it already ran cool with an engine driven fan before I switched to twin electric fans.

I decided to try the twin electric fan set up in order to see if they would free up some of the bhp that the engine driven fan always uses up.

So, as Steve suggests, I would first look at swapping your radiators core and then see how things go.

Cheers

Colyn
Colyn Firth

Dear AB, Steve and Colyn

Thanks for your responses. To be honest, I was expecting the advise to change my rad, hence the "ps" in my original posting!
I did phone Bob today and although I did not speak to him, I had a chat with his helpful assistant. Unfortunately they can't do an exchange, but have a radiator shop they send it to, who put in a modern, more effective core designed by Bob (not a typical modern core of course). Cost about £200 when adding VAT and carriage back and forth.
But I don't really want the car out of operation at present, even though (and because) we are coming in to the warmer months. So having thought it through, I have a plan! I will fit the new fan and shroud just for now, and it will be interesting to see how I get on.
I will also leave the oil cooler in place in front of the rad for the time being.
The radiator change will be on my "to do" list and deferred until the winter, unless I find that I can't manage through the summer. Seems a sensible approach to me.

I am contemplating an extra item for my master plan. I have a cheap 10 inch electric fan (80w) that I bought on eBay a while ago. Until I get the new rad in the winter, I thought it might be another helpful "sticking plaster". Are the cheap fans a waste of space compared with the likes of Kenlowe and Revotec? I guess the answer is try it and see.
Graham
Graham V

Graham.
My 1600 MkII is sitting rock steady at 180F when driving but at stand still or slow stop and go traffic the gauge shoots rapidly to over 230F.
I found this very frustrating untill I measured the actual temperature on the thermostat housing with one of these laser devices, and found that the temperature was spot on 180F.
It seems that my temp. gauge is only acurate below 190F, and way out above this reading.
As long as the water does not boil, there shoul be nothing to worry about.
Lars
L. Christiansen

Graham

I fitted the Bob West radiator a couple of winters ago and it successfully reduced my temps from around 190 to 200, to around 180 to 190. On the other hand if stuck in traffic the temp will go up to say 210 although it never boils, and as Lars said it may be the gauge. I clearly didn't achieve Steve's amazingly constant temps but I am happy.

Paul
Paul Dean

Graham
I dont know what temp your gauge shows when you said that it quickly heats up in traffic.

If it is in the 195 to 205 region it is really no big deal, if your rad filler cap is sealing as it should, the coolant shouldnt actually boil until it goes above approx 230 degrees.

I think I am like most MGA owners in that I am not so comfortable if the gauge gets to the worrying 212 degree mark, but logically, if it isnt boiling, then it is still cooling your engine.

Dont let the "Cool Running Guys" magic 175 degree running temperature worry you too much, even they will probably tell you (maybe reluctantly) that their gauges actually climb above that in traffic etc.

My gauge normally shows around 175 on cooler days and 185 on warm summer days.

I have set my twin electric fans thermostat to switch on at 200 degrees and off again at 195. This means that the fans only switch on when the car is stationary and soon switch off again as soon as the car is on the move again.

On the subject of your electric fan, if you are not changing the rad core just yet, you may as well fit it in addition to the engine driven fan and see if it helps.
I know a lot of MGA owners who have this set up and are very happy with it.
Just rig up a simple manual switch to begin with and switch it on when needle on the gauge reaches a number that you are not happy with.

Colyn
Colyn Firth

Graham, did James quote you a turnround time for the radiator? - Just in case I need to go down that route in the future.

Colyn

Trouble is I can't find any worthwhile traffic queues around Fleet at the moment. The only time I see 190 is where it peaks after shutdown. The other Colin bore witness to that at his local meet recently. We were also able to put our hands on the top tank.

I sometimes wonder if the higher gearing (lower revs) on my car, plus the MGB expansion tank on the firewall shelf in the line of the fan draught are contributing factures.

Steve
Steve Gyles

Steve,
If you are looking for traffic queues around Fleet look no further than the M3. I spent 2 1/2 hours travelling the 7 miles from Bagshot J3 to J4A last week, keenly looking for anything happening in the two lanes closed for resurfacing. Not even a trowel in sight. I was pleased not to be in my A-without-a-Bob-West-spec-radiator. Several modern cars keeled over. Many drivers also climbed out to let off steam (or so it appeared...)
Shane
Shanerj

Thanks for the feedback.
Lars, I did check my gauge at 212d last summer, so unfortunately I don't think it's the gauge.
Paul thanks for confirmation, and I am resolved to make the rad change in due course.
Colyn. The gauge went up to just over 220. It was quite a warm day, and I was stuck in a long heavy traffic jam leading into Henley. As soon as I was able to start moving properly it quickly dropped. I know the cap seals well, as I drained it this afternoon, and hardly anything came out when I opened the tap, until I removed the cap. I also have silicate antifreeze/coolant that should also raise the boiling point.
You are absolutely right, I become very uncomfortable at such times, and completely obsessed with the gauge. And I'm not really wanting to be a super cool dude,
Steve:- He told me the turnaround was only a few days at their end but when I add carriage to and back, plus the Graham factor (anything that could go wrong with the delivery, will go wrong, etc) it will I am sure be a couple of weeks.
Many thanks, Graham
Graham V

I agree with Steve Gyle's initial assessment. At the risk of inciting groans, surely "the core of the problem" is the radiator. Other peripheral issues contribute marginally, and have often been listed. Those with original type cell core (V-cell) radiators, Bob West radiators and custom made aluminium radiators (me) don't seem to have problems.
I don't think moving the oil cooler will have much impact, but at the cost of potentially cutting your car about a bit. Additionally an oil cooler adds only a little to overall engine cooling despite what's claimed in that "Barron" article. An oil cooler's main benefit is in maintaining oil viscosity under arduous conditions. Some question their need at all with modern oils. The dominant engine heat transfer is through the coolant and its radiator. Water/coolant absorbs and dumps heat much faster than oil.
As for me, in hot Australia, with an aluminium radiator, factory 10 row oil cooler in front of the radiator, and a fan shroud, I've found no need for supplementary electric fans. Even in traffic jams in summer I don't believe I've seen over 195F on my gauge. Indeed with my new 18V engine transplant I exchanged the 165F hi-flow thermostat for a 185F thermostat, with still no problems.
T Aczel

This thread was discussed between 16/05/2016 and 17/05/2016

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