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MG MGB Technical - Overheating and Oil Coolers

Hi,

I have just removed an oil cooler from a '75 B (which didn't have a cooler originally, so it must have been added by a PO) because it was restricting air flow past the rad to the point that on hot temperature days (high 20's C) the car would border on overheating. The car has a recored rad, a plastic fan, and a new thermostat (180) and waterpump.
Is this a common problem with adding oil coolers to R/B cars?

JR
JR Ross

Should run a tad cooler with an oil cooler.

I'm not one to remember air flow on RB cars
glg

JR. The 75, and perhaps the 76, must have used the same position as previous CB cars. From at least 77 onwards the oil cooler is mounted below the valance and out of the primary air flow. I am not sure the exact point where this took place, but do know that my daughter's 77 and both of my 79s have the cooler mounted under the valance.

As to blocking the air flow. I did not notice any change in operating temperature on my 68 GT when I had to pull the oil cooler out because it cracked a fitting. Indicated temperature on the dash gauge was the same with and without the cooler in place.

I have been doing some experiments on the cooling system since I got an infared thermometer. When the temp gauge on my 68 is showing 3/4 of the way up the scale, the cylinder head is showing about 185 deg F. I am laid up right now and cannot do much driving or working. But, as summer progresses, I hope to be able to determine more about what the actual temperatures are within the cylinder head when the outside air temps are in the 110F deg. range. In the mean time, I would suggest you might want to determine exactly how hot the cylinder head is getting when you get the "overheating indications". Les
Les Bengtson

There is no advantage in cooling in removing the oil coller , it also carries away heat that otherwise has to be dumped into the water .
S Best

JR

If water is running hot then so will oil temp.

The oil however is front line and when working engine will run even hotter, so the oil cooler is used to contol high oil temps. There are temp strips that can show max oil temp.

At speed the water temp should be stable as its controlled by themostat, if its not the system must be at cooling capacity. Removing oil cooler will help airflow and water cooling but oil temp may be higher as a result when working engine. The decision is whether an oil cooler is needed and is there enough water cooling capacity for your ambient air temps.

Paul
Paul

Thanks for the info folks.
Since the removal of the oil cooler has solved the overheating condition, I must assume that there must be a restriction to the flow of air through the oil cooler itself, which, in turn, is restricting air flow past the rad.

JR
JR Ross

Or the cooling efficiency of your radiator is marginal enough that removing the cooler had an effect. Just another way to look at the info. Could be you need to clean out the rad and cooling jacket in the block.
Bob Muenchausen

This thread was discussed between 20/06/2004 and 21/06/2004

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