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MG MGB Technical - Vents in inner wings

I've read that holes cut into the inner wings are good for cooling the engine bay as there is a low pressure area in the wheel-well that sucks air from the underbonnet area.

RV8s have holes through which pass the exhausts.

Has anyone done this? What does anyone think about strength considerations... the 'chassis' rail is massive and hence I'm not sure that the inner wing does much other than hold the outer wing on!

Thanks,

N
Neil22

On the RV8 they welded a reinforcing ring around the exhaust hole, so when I cut my inner wings for the V8 exhausts I did the same. Whether it adds any strength, I have no idea.

But really, an 1800 MGB should not need them. The cooling system should be more than capable of keeping the engine at a good working temperature in any sort of British weather. There are people using them in Texas without trouble!
Mike Howlett

Yes - but only with the V8 fitted still with blockhuggers. I totally agree with Mike about the 1800.
R Walker

Certainly a hole cut in the inner wing would not affect the structure in any way but quite frankly there is no need to do this as the temperature under the 1800 bonnet never rises to and great degree. Don't worry about it.
Iain MacKintosh

It's the structure I'm asking about; whether the inner wing really does anything structurally given that the cross member is bolted to a massive longitudinal member.

N
Neil22

The MGB is a bit undercooled, mine is fine with the Moss Shroud, but if it didnt have an aluminium bonnet I would use an idea shared on this board in the past and have louvres punched in it near to the trailing edge. Its true that this is a high pressure area when the car is moving, but there isnt a problem then, its only when you are stuck at a standstill, and then natural convection lets the warm air out through them.
I cant imagine that a small hole in the inner wing is a structural issue. I would be concerned with road dirt getting in though if the pressure is in the wrong direction sometimes.
Stan Best

Whether it is structurally required in the case of the MGB I don't know. But,it is considered as good engineering practise to install a strengthening piece around any sizable hole cut in sheet metal.Our local motor registry has a directive aimed at hot rodders & custom car builders, that if they have to cut a hole for a floor gear shifter, the hole has to be reinforced.Just like the one on an MGB. I think it also gives a better & more professional appearance to the engine bay. Barrie E
B Egerton

This thread was discussed between 22/02/2012 and 25/02/2012

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