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MG MGB Technical - B/L dealer installed A/C

I am restoring a 1980 MGB that came with a dealer installed A/C unit.

I run a Nostalgic A/C unit in my 1970 B and it performs satisfactorily up to about 40°C in the desert heat of New Mexico and Texas. I have made many adjustments and adaptations over the years to increase reliability and improve drivability. Belt alignment is a particular challenge and achieving this is an absolute requirement for reliability on long journeys.

It appears that the condenser unit is very small on the 1980 B and I am wondering if these systems performed adequately when the cars were delivered. They did run R12 refrigerant which was less demanding than R134. I have converted a couple of Volvo R12 systems to R134 and performance is satisfactory. The MG "factory air" also runs the Lucas alternator which would seem undersized for the additional electrical load requirement (compressor clutch and interior fan as well as OEM "pusher"cooling fans).

Any comments regarding the Leyland MGB A/C performance would be appreciated. An installation manual for the dealers would be an asset and by now, a collector's item for the library.
Glenn Mallory

Hey Glenn--I've never seen a factory AC on a B here but with other cars, i've done quite a few retrofits from R12 to 134a gas and the secret for good cooling is to have the gas charge a bit on the low side--You need the low side pressure to be getting right down when it's working hard, if it's too high the cooling ability will be less. Don't gas it using the sight glass method 'untill there's no bubbles'--R134a will always have a few bubbles.
Are you using a TX valve or a set orifice system.
I'm thinking RV8's had air so maybe Moss might have the condenser size listed for them---just to compare.

willy
William Revit

Apparently MGRV8's had a pair of condensers, each mounted underneath/inboard from the headlights with a fan on each one. Sounds a bit weird but out of the airflow to the engine radiator i guess.
William Revit

This thread was discussed on 27/06/2024

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