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MG MGB Technical - Heater or lack of it!

When a heater isnt fitted to an MGB, what actually is fitted in the way of air pipes, controls etc?

Thanks

colin
Colin Parkinson

Everything is blanked off with plugs. RAY
rjm RAY

Ray, so no airflow at all?

Car will be in a warm climate, so I was just wondering what the options were. Maybe Aircon???

Colin
Colin Parkinson

Was there not a 'fresh air' option, as with the Spridget?
Dave O'Neill2

Clausager he say: A fresh-air unit was an option for warmer climates, simply the heater without the matrix, coolant pipes or water valve, and consequently only had the air direction control on the dash. Common for Australia until April 69 when it was dropped, and shortly after that dropped altogether.
PaulH Solihull

Thanks Paul. Makes sense!

Colin
Colin Parkinson

What Ray says is correct for early Australian cars but the big fresh air flap was always there.
Ian Buckley

"A fresh-air unit was an option for warmer climates, simply the heater without the matrix, coolant pipes or water valve, and consequently only had the air direction control on the dash. Common for Australia until April 69 when it was dropped, and shortly after that dropped altogether"

Heaters used to be an optional extra for Australian assembled MGA and MGB cars. It was rarely fitted to the MGA and even earlier MGB cars (such as my 1965 build MGB). From January 1969 the "ADR" (Australian Design Rules) came into force. These mandated amongst other things, that all Australian built cars had to be fitted with demisters. Never a company to waste money, BMC (Australia) clearly thought, for a time anyway, that it was more economical to save the massive expensive of the heater core and associated water valve, heater control, cable and coolant pipes that a heater entailed, preferring instead to stock both heaters and "fresh air/demister" units, and to fit the heater only where the purchaser coughed up the extra dollars for a complete heater with their order. The increased complications in stores and on the production line for the saving of a few dollars must have quickly become obvious, and all cars were ultimately fitted with heaters.

For MGBs without a heater, such as mine originally was, a metal blanking plate is fitted to the heater shelf where the heater otherwise resides, and the two holes for the heater control and air distribution knob on the dashboard had blanking plugs. The central fresh air flap behind the speaker under the dashboard was still fitted, carrying air introduced from the grille on the scuttle in front of the windscreen. The two metal flaps introducing air from the plenum chamber to the two footwells was also fitted, whether cars had a heater or not.
T Aczel

Mr Aczel, perfect, just what I wanted, except you omitted to say what went in the hole on the dash where the square plastic fresh air vents are.

Colin
Colin Parkinson

Colin, the MGB was assembled in Australia from April 1963 to November 1972, inclusive.
For the cars with or without a heater, the "hole in the dash where the square plastic fresh air vents are" was occupied by the radio if fitted, or by a blanking plate (in black crackle finish like the dashboard with the MG octagon) if there was no radio fitted up to and including 1971. The centre panel linking the base of the dashboard to the top of the transmission tunnel was occupied in these cars by the radio speaker, in an octagonal surround, rather than an interior light, radio and switches (or blanking plugs) as on the 1972 or later cars.
The dashboard fresh air vents you refer to were only introduced in Australia during the course of 1972, the last year of Australian assembly, by when all cars had a heater fitted anyway.
I trust this helps you (rather than confuses).
T Aczel

"The two metal flaps introducing air from the plenum chamber to the two footwells was also fitted, whether cars had a heater or not."

Presumably they did nothing if there was a metal plate over the hole in the heater shelf.
PaulH Solihull

"The two metal flaps introducing air from the plenum chamber to the two footwells was also fitted, whether cars had a heater or not."

Presumably they did nothing if there was a metal plate over the hole in the heater shelf
Paul that is correct, as I recall. (I fitted a heater to my MGB about 30 years ago, so I no longer remember for sure).

The non-heater MGBs also had the demister outlets and the underdash "funnels" fitted, but the MGA was lacking the "funnels" and just had the "slots" on top.

Colin, I'd imagine there's not a huge demand for them, but I have two spare heater shelf blanking panels in my shed if you need one. (I was very surprised to see some spirited bidding for one offered on Australian eBay a couple of years back). They resemble a smaller version of the panel over the battery trays. It would be easy to fabricate one too; probably easier than posting one from Australia! You'll also need a round blanking plate for the air intake on the firewall face behind the heater. I doubt if I still have one of those.
T Aczel

Thanks for that Mr Aczel. I have already made blanking plates as the car was going to be a race car. Change of plans means that it will remain a road car and will go with me to Barbados as a project in my retirement!

But I do like to get the detail correct if possible.

Thanks everyone for your help.

Colin
Colin Parkinson

This thread was discussed between 01/03/2013 and 04/03/2013

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