Hello - I have a 1963 MGB which I'm currently restoring. I just wondered what the current thinking on cooling is? I used to run the car with a standard radiator and a Kenlowe fan, which worked pretty well. I notice you can now get larger aluminum radiators which provide better cooling - and perhaps don't require a Kenlowe? The car also has an oil cooler. Any advice would be much appreciated,
Paul
Essex
MGB Cooling
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Jose Fuste
- Posts: 1
- Joined: Sat Jul 11, 2026 1:57 pm
- Forename: Jose
- Surname: Fuste
Re: MGB Cooling
Good day and regards from Puerto Rico. I have a 1971 MGB and installed a Moss-supplied large-capacity aluminum radiator with a multi-blade yellow plastic fan and cowling. The car never overheats. Strongly recommend it. Another source for quality radiators is Basil Adams, 707 762 0974; [email protected]
Re: MGB Cooling
Paul, I know it's currently hot in Essex - it's quite warm on the west coast of Scotland. The MGB as designed should be able to cope with the sort of temperatures you are currently seeing. After all, it was built to be exported to the USA which can get very high temps in some areas. Have you found it over-heating, by which I mean the system losing coolant, not a slight rise on the gauge? Of course, after 60 years the cooling system might not be as effective as it once was - blockage of water galleries in the engine is not unknown.
Are you running the engine fan as well as the Kenlowe? They will have vastly different flow rates and might interfere with each other, making both less efficient. My opinion is that the oil cooler adds very little to the engine cooling. I put one of those thermostatic controls in the pipework. It wouldn't allow oil to go to the cooler until the oil was over 85 Celsius. Even on hot days I could get home, pop the bonnet and feel the cooler and it would usually be cold. Here's something to ponder, the RV8 with the 3.9 V8 engine in a revised MGB body generates massive amounts of heat. Did they fit an oil cooler - no they didn't. My own '69 BGT conversion has the same 3.9 engine without a cooler and has never overheated, even in southern France.
Yes you can fit a larger more effective radiator, but do you need it? The danger you could have is that on cooler days, like the majority of UK days, the car might be over-cooled which is detrimental to the engine.
Are you running the engine fan as well as the Kenlowe? They will have vastly different flow rates and might interfere with each other, making both less efficient. My opinion is that the oil cooler adds very little to the engine cooling. I put one of those thermostatic controls in the pipework. It wouldn't allow oil to go to the cooler until the oil was over 85 Celsius. Even on hot days I could get home, pop the bonnet and feel the cooler and it would usually be cold. Here's something to ponder, the RV8 with the 3.9 V8 engine in a revised MGB body generates massive amounts of heat. Did they fit an oil cooler - no they didn't. My own '69 BGT conversion has the same 3.9 engine without a cooler and has never overheated, even in southern France.
Yes you can fit a larger more effective radiator, but do you need it? The danger you could have is that on cooler days, like the majority of UK days, the car might be over-cooled which is detrimental to the engine.
Mike
1969 MGB GTV8 3.9 Conversion. Many classics have passed through my hands but the faithful BGT V8 is the last man standing.
1969 MGB GTV8 3.9 Conversion. Many classics have passed through my hands but the faithful BGT V8 is the last man standing.
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Not_Anumber
- Posts: 414
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- Forename: Chris
- Surname: S
- Location: UK
Re: MGB Cooling
I changed to an uprated aluminium rad in my RB but chiefly as mine in an engine swapped car and the original rad had a slow leak so it needed to be replaced with something.
Personally if yours is a standard B I would trust in the capacity of the standard cooling system. The standard radiator specified for the B is pretty good even by modern car standards and so long as it is free from blockages should be more than fine for the > 30 C weather we are experiencing currently in the South east. .
Was the Kenlowe fan added by yourself as a precaution or as a reaction to an episode of overheating ?
Personally if yours is a standard B I would trust in the capacity of the standard cooling system. The standard radiator specified for the B is pretty good even by modern car standards and so long as it is free from blockages should be more than fine for the > 30 C weather we are experiencing currently in the South east. .
Was the Kenlowe fan added by yourself as a precaution or as a reaction to an episode of overheating ?
1979 MGB GT
1999 Jaguar XKR
2003 MG TF
1999 Jaguar XKR
2003 MG TF
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MikeD
- Posts: 11
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- Forename: Mike
- Surname: Dixon
- MGCC Member: Yes
- Location: S Wiltshire
Re: MGB Cooling
I run a B with standard rad, cooling fan and coolant. Touch wood it has been fine - we did HERO London Lisbon in it in 30 deg+ over the Pyrenees, several times back and forth. It got a bit warm but did not overheat .
Re: MGB Cooling
Hi. My 72B has the original style radiator and a 7 blade plastic fan, no overheating issues. You may want to check your 10v voltage regulator , the one that feeds the fuel and temperature gauge. If it has gone faulty you may be getting high temperature readings.
Regards
Paul
Regards
Paul
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Not_Anumber
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- Joined: Tue Sep 22, 2020 9:33 am
- Forename: Chris
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- Location: UK
Re: MGB Cooling
Always worth checking the basics.
To make sure the water jacket in the engine isnt full of detritus flush it out with a garden hose. When you undo the drain valve on the side of the engine near the distributor does coolant flow out or is this blocked up with crud and needs rodding ?
To make sure the water jacket in the engine isnt full of detritus flush it out with a garden hose. When you undo the drain valve on the side of the engine near the distributor does coolant flow out or is this blocked up with crud and needs rodding ?
1979 MGB GT
1999 Jaguar XKR
2003 MG TF
1999 Jaguar XKR
2003 MG TF
Re: MGB Cooling
Hi I have a 1970 mgbgt with an 18v engine. It never ever overheats in any conditions.
1. You must make sure that all internal engine waterways are spotless, and must be kept that way, I use 100% G30 coolant, 100 % is not the most efficient
For cooling. But there is absolutely no corrosion, or sludge build up.
2. A good quality water pump.
3. Radiator, no good just flushing the old one, if possible stay away the Chinese ones. Try to get an old original one standard one and have it re-cored with a good quality core.
4. This is a must, dump the original tin fan, and fit a yellow 7 blade plastic fan.
Incidentally, I currently have an 88 C thermostat for winter use, but it’s actually been in all summer and it’s ok.
I do not have an electric fan, and don’t need one. Hope this helps. John
1. You must make sure that all internal engine waterways are spotless, and must be kept that way, I use 100% G30 coolant, 100 % is not the most efficient
For cooling. But there is absolutely no corrosion, or sludge build up.
2. A good quality water pump.
3. Radiator, no good just flushing the old one, if possible stay away the Chinese ones. Try to get an old original one standard one and have it re-cored with a good quality core.
4. This is a must, dump the original tin fan, and fit a yellow 7 blade plastic fan.
Incidentally, I currently have an 88 C thermostat for winter use, but it’s actually been in all summer and it’s ok.
I do not have an electric fan, and don’t need one. Hope this helps. John