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MG MGB GT V8 Factory Originals Technical - Heater Removal Yes/No?

Just me again,

This time I'm going to open a can of worms but here goes...

Has anybody given thought to the permanent removal of the heater? I live in a reasonable climate and would like to reduce car weight as much as possible. With the standard B engine I found it was warm enough without the heater, and I suspect the V8 will be similar.

My other plan is if the heater was removed I can reroute the air straight from the engine bay, through the heater hole and pipe it to the vent in front of the windscreen. Sounds a bit bizarre I know but it would help out with that age old problem of hot air removal from the engine bay.

Tell me what you think,



I removed my heater to move the engine(turbo 4) further back to clear the steering rack. I plan on relocating the heater behind the seats and running the plumbing up to where it origionally was. As far as just pulling the hot air from the engine bay, I imagine there would be too many fumes to mess with.

G.P. Copes

If removal of every gramme of excess weight is the prime aim then ousting the heater will help there.

One point though is the heater matrix does add to the cooling of the engine albeit not intentionally.

If I read your post the right way you are planning to duct the engine air out via the intake vent just ahead of the screen.
Is this right?

You may find this is a high pressure are which is why the intake vent is there so the flow may be stalled by the build up of high pressure air at that point.

Adding extra exits to the wheel arch inner panels may be a better alternative since these are already low pressure areas and the air under the bonnet is in a region of somewhat higher pressure.
The extarnal look would be the same and you can duct cold air into the cabin via the intake vent ahead of the screen if you want to.

Some thoughts.
Cheers, Pete.
Peter Thomas

Stainz,I have hear of this being done before, so yes it is possible. Also rememerber that that air openeing draws air IN not out.. Many people think it acts like a cowled hood, but it does not. with a cowled hood like you see on allot of camaro's the hood raises up then suddenly stops, this makes a low pressure spot behind the rise which draws the air out. The place were the heater inlet is, is in a region of higher pressure created by air hitting the windscreena and having to find a place to go.. This also feeds the ducting in your dash for fresh air..

Use it as a cold air intake, and you should se a better performing motor!! Or use it for a fresh cool air entry poin for your engine bay. I am not sure what fan/rad set-up you are using, but if you have a big electric fan ducted to the rad this may provide more pos pressure to the engine bay to force the hot air out, but I would be concerned about it limiting airflow through the radiator as well..?? just a random though there..
Larry Embrey

Thanks guys,

Looks like back to the drawing board....I didn't think enough about the airflow direction at the vent in front of the windscreen. I was keen to chuck the heater if there was going to be a bunch of benefits, but just to save 5 pounds is probably not worth it. I'm also using RV8 manifolds which should help cooling anyway.



The original cowl hoods on 1st generation Camaros was called cowl induction or cold air hood because the air cleaner was sealed to the hood and the carb drew fresh, cooler air in from the back of the cowl.

Wasn't it here just a few weeks ago that people were raving about how much better their engine cooling was with just the sealing strip on the bonnet rear edge removed???? I've seen the heater mod done on a Cosworth conversion. Even if it is a high-pressure zone then air will pump down it and still aid engine bay cooling, but with air being rammed in the front I would have throught that pressure in the engine bay would be higher. The worst it will do is nothing at all like the standard setup. And while stationary in traffic it will be a great benefit. If you are removing the heater then you have nothing to lose ... except internal ventilation, of course.
Paul Hunt


I omitted the heater on my conversion, and used the cool, high pressure air at the cowl for the engine intake. Here's a photograph that shows exactly what the bulkhead modifications and the air filter look like (scroll down to my name...)

If you decide to go that way, I could e-mail you photos of the "other half" of the air filter housing, etc. It's worked great for ten years...


This thread was discussed between 14/09/2002 and 16/09/2002

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