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MG MGA - Radiator Survey

In an adjacent thread Dominic suggested that it may be a useful exercise to log our radiator details against running temps etc to see if there is a common denominator causing the many overheating issues suffered by owners worldwide.

So I will kick off with the details of my 'cool runner' in the temperate UK climate.

My radiator is close to the original MGA specification, supplied by Bob West. The core thickness is 2 inches and I run it with an MGB expansion tank. Standard 6-blade fan on an 1800V engine; no shroud, just the felt above the tank. The engine runs at 175 all day regardless of speed. It might creep up to 190 max in queuing traffic, otherwise a very static temp gauge (which I have calibrated as accurate).

Steve
Steve Gyles

Standard everything on a 1959 Twin Cam (engine driven fan, water pump, no shroud, felt strip bonnet/rad, normal header tank, 4Life coolant, conventional radiator from Bob West). Runs at 175 F all day, maybe 195 F queueing in hot weather.
Bruce.
Bruce Mayo

Bob West radiator (7 years old) with std header tank.
Water/antifreeze mix(40% AF).

1850cc 105bhp engine.

Twin 9" electric fans, thermostatically controlled fitted on the front of the radiator.

No engine driven fan.

No radiator shroud.

No felt pad above radiator.

Bonnet has 2 rows of louvres towards the rear.

Thermostatically controlled oil cooler fitted BENEATH the radiator duct panel with its own ventilation grille.

Runs between 175 and 185 when moving.

Temperature rises rapidly when stopped in traffic but the electric fans cut in and brings temperature down equally rapidly to 195.

In very high ambient temperatures over 100 degrees F or 40C, on long, high speed, uphill motorway sections, the temperature rises to around 195 degrees but the twin fans soon bring this down to 175 or less.
c firth

It would be nice to know what the various radiator designs are e.g. cell core, tube and fin and I think I've seen an early radiator or two with honeycomb cores. And, if the core is T & F, how many rows of tubes there are and whether they are staggered or in line.
I believe Bob West, at one time, supplied a 3 rows in line T & F core.
The trouble is that it is not too easy to see by inspecting the core face how many rows there are. It's possible to say whether the tubes are staggered or not by inserting a wire into the core and moving it left to right. If it only goes half way between visible tubes it is a staggered construction.
I've looked at my T & F core on the car and there are 36 tubes per row laterally and the rows are staggered but I can't say how many rows there are.
The s/h cell core radiator I've just bought has 33 'tubes' in line (or in one piece) and it seems to have just two rows .

But the cell core is incredibly open mesh, you can almost read a newspaper through it whereas the T & F core is virtually black... .......................Mike
m.j. moore

1800 3-main long block with MGA bits attached. Basically a stock engine. Stock radiator tanks with 2-row MX (dual pass) core. The car can't handle high temperatures while climbing long steep grades or sitting in heavy traffic. High temperatures to me are 100+F. On flat ground at moderate speeds it runs cool, and in normal temperatures it runs cool.
Steve Simmons

Hi
I have a standard 1622 cc engine. I had my rad recored earlier this year with a "standard modern" recore (probably not the best choice with hindsight). On warm days it runs at 195 but creeps up to 200 on motorway.
I replaced the Mk 2 grill with a mesh grill which made a significant improvement to cooling. I have read rumours that the after market grills are not as effective as the original were. The felt's in place, plus new pump and thermostat.

Two points confuse me. First, are we comparing like with like? What I'm saying is when I eventually convert to a 5 speed gearbox, the cruising rpm will drop significantly, so I'm thinking the increased temperature at higher speed might clear itself - i.e. so do 5 speed cars cruise cooler than 4 speed?

Second, what should the optimum temperature actually be? Engines need to be hot and my standard thermostat opens at 180 degrees, so I assume the design was for the car to run above that i.e. is 175df - 180dF actually too cool? And what's the problem with say 200df? The system is under pressure and with anti-freeze, the boiling temperature is well above 212dF

What do you think?
Graham V

Hi Steve. I turned on cable tv the other day and came across a segment on restoring a TC. Then they swapped to LA, and who should I see discussing his red TC and extolling their virtues but Steve S himself!

As for cooling, as is likely fairly well known by many now following the recent series of posts, I have NIL hot running issues no matter the traffic, gradient, speed or temperature. Generally sit on the thermostat set temperature. In traffic jams on hot days I'll see 195F on the (checked for accuracy) gauge.
For me the recipe is:
(Australian) "PWR" aluminium single row, single pass radiator incorporating a few clever internal design tricks.
Standard engine driven fan + shroud
Felt block on bonnet above radiator.
Blanking sleeve.
Standard factory fitted 10 row oil cooler on duct panel, and therefore in front of radiator.
Cool air duct to carburettors in place.
Expansion tank.
👍 😀
T Aczel

Graeme

You make very valid comments about comparing like for like when so many of us have modified our cars with the 1800 engine and 5-speed box etc. But I guess that is what analysis is all about. The samples so far received are too small in number to make any real conclusions, especially as 3 of the 4 UK contributions are from 'cool' runners. Interesting though that those 3 are essentially similar to original spec. Yours is the only 'hot' one to date and its radiator history is unknown. It is the hot runners we really want to see posting here with as much detail as possible about their radiator history - local radiator shop with modern core; Moss; other suppliers etc etc.

May be we will find that the cool running owners know the precise history of their rads, whereas the majority of hot runners don't - and that could tell its own story.

So, come on hot runners, post your details.

Steve
Steve Gyles

Mine overheats badly in stationary/stopped traffic on hot days. Moving it is fine.

I have:

1500 engine rebored to 1600 with 5 speed gearbox.

Engine driven fan, no shroud

No felt pad.

Repro grille.

I am pretty certain that the radiator is the one it left the factory with so probably past its best. The airways look OK but I have no idea of the state of the water passages. I have flushed it with some sort of commercial product, can't remember what, with no benefit whatsoever.

I am also on a replacement engine the first one having broken a con rod with all sorts of damage resulting. Both engines have reacted virtually identically to weather/traffic so I don't think the overheating is an engine problem. The waterways were as clear as I could get them on the "new" engine. I am considering getting the radiator rebuilt this winter.
Malcolm Asquith

I have a 1500 Coupe the 1500 engine rebored to 1600 about ten years ago

No felt strip over radiator
2 rows of vents 20 per row 4inches wide in the bonnet

The vents have reduced the running temp.by a estimated 10 degrees.....Used to run at 185-195 now runs at 175-185 depending on weather and traffic....Rex
Rex Thompson

High temps in Aus. as we go into summer.

My set-up: Removed the original radiator and replaced with new (not V-cell) Still over-heats (212 +) in slow traffic or standing in line. Can boil over when ignition turned off.
Original engine fan and Craig -Davies thermostatically operated electric fan mounted forward of radiator.
5 bearing 1800 motor bored o/size.
Felt above radiator in correct position.
No blanking sleeve or shroud.
13 row oil cooler mounted below gravel tray.
Brass Morris 1800 type expansion tank.

Previous motor was a 1620 and heating problem has not changed. Barry
Barry Gannon

Adding to my earlier post - I have extensively modified the front, as you will see from the photo, but the cooling, if anything, should be better as I have provided an air scoop (on the lower edge) and large air holes to get extra cooling to the oil cooler without inhibiting the normal flow of air to the radiator.

Barry.


Barry Gannon

Mine is a Mk 2 Coupe with original 1622 fast road engine mated to a 5 speed box -radiator original MGA type with standard fan and additional Kenlowe in front of radiator No shroud no modifications to body
Car runs all day at around 165-170 rises to 195 in stationary traffic hardly ever use the kenlowe only ocasionally in traffic jams (I have removed the Kenlowe Thermostatic control and just have a manual override switch.) In very hot weather 30-35 degrees will run a bit hotter and may rise to 195 when idling in traffic
Will cruise all day at 70 mph and temp may hit 185
Did have some cooling problems when the timing was incorrect but corrected timing and carb tuning and have not had any cooling problems since
Paul
P D Camp

Paul's post reminds me of my earlier point, and would be interested to hear opinions.
As I said, we all know engines need to be hot, but how hot? The standard thermostat must be a good indication of what the designers intended and that opens at 180 degrees, so presumably 180dF should be the absolute minimum temperature?
Do people in the UK who run at lower temperatures have thermostats that hardly ever open or do they use the hot climate thermostat even though the UK can hardly claim to be that.

Whilst none of us want to over-heat, what is the utopia. I am just wondering if the cars should be running at slightly higher temperatures, as after all, if 195 - 200dF is too hot, why do we have pressuriesed radiator caps, to allow the temperature to rise over 212dF without boiling?

Or is it that on some cars, that are running well at 165 - 170dF like Paul's (which I know is a nice car) actually do have their thermostats operating as they should to keep the temperature up, but the temperature guages are perhaps inaccurate?

Guess I might be upsetting some cool dudes, but am interested at what we should be trying to aim at as I suspect 165df is to cool

Graham
Graham V

Very similar temp profile to Steve but 5 dog higher,I.e. base temp is 180. Engine is 3 bearing MGB. Radiator recorded by Bob West last winter which brought temps down by 5 to 10 deg. Otherwise std setup.

Paul
Paul Dean

Supercharged 1622 engine with Peter Burgess supercharger head, lightened flywheel and fast road cam, five speed gearbox. Bodywork is completely standard apart from a mesh grille. Standard locally recored original spec radiator with 180F thermostat, engine fan and oil cooler. Running temp regardless of speed and traffic is stable around 75-80C, which is 165-175F. Going hard up a mountain pass will cause temp to rise 10-15C, going back down temperature drops to 65-70C.

Once I had to tow someone over a pass, and when the temp reached 100C, I just stopped, unhooked the other car and drove 500m down the mountain and back up again and that was enough to drop temperature to 75C again. When using the original Holley carb with the supercharger, carb icing was a problem, even though the carb is directly above the exhaust manifold.

In cold weather the car needs its radiator blind closed to allow running temperature to be reached, otherwise only 50C is achieved. Thermostat opening is visible when the needle on the gauge drops, at which point the blind can be lowered a bit.

Gauge has been checked against a digital thermometer and in boiling water and is proved to be accurate.
dominic clancy

Hmmm

I think for this thread to make sense you may need some extra details filled in that are not present like:

Camshaft Spec.

Timing.Settings

Carb settings plus carb used.

Exhaust. Type of finish

Radiator type

Head...and any work done.

Valve settings

Oil cooler or not

thermostat

coil type

plug type and number

Type of gas you run. high test or cheap stuff.

Compression ratio or poundage

Milage. I noticed when my engines were new they ran hotter. After 3500 miles they cooled right down.

I think with out all the data we are kinda chasing our tails.

Im sure theres more Im missing

Wouldnt it be great to have all this stuff!
Steven Devine

Interesting mix. I am going to offer my car as a baseline or control: 1958 MGA, stock 1500, SU's, original manifolds, heat shield, original radiator, 180 degree thermostat w/ blanking sleeve, 50/50 antifreeze/water mix, original grill, correct felt pad, etc. around the radiator. The car does not overheat. The temperature will rise to 200 or so on long runs like going over the Blue Ridge Mountains or while stuck at a light on hot summer days but falls immediately when the grade decreases or the car gets underway. I have had the car 20 years and overheating has never been an issue.
Bill Haglan

Could I suggest a possible experiment for the radiator club!?

This could be done in both the UK and here in the US (and other areas as well)

Have those with heating issues simply swap out their current radiator with a known original in working condition. I have an original radiator and am happy to send it to anyone here in the US who is having overheating issues. We simply swap out the radiator (six bolts and two hose clamps), The owner could then have an almost immediate comparison in radiator function.

The variations in engine size, gearbox and modifications would not matter in this test.

Any thoughts? I will take my original in and have it cleaned out - not rodded out of course - and pressure tested up to 4 or 7 pounds.

It is then available for testing purposes.

I will watch this space!

Best regards
DLD

Thats a good Idea! Thanks to good mine dont overheat. I still think youve got a good Idea though!
Steven Devine

Re Grahams point re Thermostat opening
I suspect mine is a 160 thermostat as this is when the temp guage drops after 5-10 minutes from cold when obviously the thermostat has opened- and then rises to 160-170 when fully warm
Either that or my guage is reading 20 under ?
Paul
P D Camp

just a thought on "wheeler Dealers" recently Ed China used some waterless coolent in a TR6 they were doing saying that it would eliminate all cooling issues?

cheers Gordon
G C Pugh

Paul
Its easy enough of course to pull out the sender and test the temperature gauge in some boiling water.
But my point was more about whether figures such as 165dF might actually be too low? - hence the reference to standard thermostats and radiator caps
Graham V

The one thing I did not see is what is the outside ambient temperature when these test are being done. I live in Southern California and our temp is about 70 degrees and in the summer it is 90-105 degrees on really hot days. My car runs hot even on a slow drive in normal temperatures. I am interested in he "waterless" coolant.
JEFF BECKER

Gordon and Jeff
Peter Burgess on his website warns against using waterless coolant.
I seem to recall him saying tthat water is a better cooling agent and you risk cracking your cyl head with waterless.
Colyn
c firth

I happened to find a close up of my PWR aluminium core.
I had no idea I had this on my computer till just now. It's a single row, single pass design.
As I'd mentioned, the radiator works superbly well in our arduous Australian conditions, without need for supplementary electric fans. It's a single row, single pass design.
Close inspection shows a surprisingly similar appearance to an original style v cell core I thought, with large spaces for the air to pass through.
I hope the photo has enough resolution to show the matrix well. I'll give it a go.


T Aczel

See http://www.oilem.com/category/waterless-engine-coolant/ on the subject of waterless coolants generally, and Peter'ssite for a very informed piece relating to MGB engines.

On the physics:
Water has a specific heat capacity of 4.18, which means it is excellent at transferring heat. Water freezes at around 0C depending on impurities and altitude. Pure water / distilled water in cooling systems also cause corrosion, which degrades cooling system performance. For these two reasons we add coolant additives / antifreeze (according to climate - antifreeze also has corrosion inhibitors) which have a small effect on specific heat capacities. Waterless coolants have a much lower specific heat capacity, which means they absorb and move heat to your radiator a much lower rate than water. So for the same radiator area, your system will run hotter.

Water is also cheap and unmatched in its qualities for heat transfer. That is why it is so widely used...
dominic clancy

Had a lot of trouble with my 1600 with Xflow head and 5 speed gearbox and read a lot of previous comments. Opened up the grille slats by twisting them carefully. Thoroughly cleaned the rad with proprietry cleaner and flushed through engine and rad. Refitted felt pad. Filled with Evans waterless coolant. Pricey but does not evaporate. Now runs at 80C in English summer and only 90C in traffic jam. Mind you have not been to Italy in summer lately!
H L Davy

See my post "overheating solved"in this forum.
David Holmes

This thread was discussed between 25/11/2015 and 21/12/2015

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