As of: 10 June 2002
Installing Fresh Air Vents in Dash
The 1972-1980 MGB's had face-level air vents centered in their dash. Some of those vents were hooked up to draw fresh air directly from the outside of the car to the driver's face. It always seemed to me that all MGB's should've also had them. Recently, I acquired a stripped body that was prepped for the vents though they had never been installed. Looking at the firewall, I realized that the installation was a rather straight-forward modification.
The photo below shows the firewall of that car after the dash was removed.
There are 2 each 2-1/2" holes through the inner firewall into the cavity below the fresh air intake grille. You may not be able to see it in the photo, but between and below the 2 holes, inside the air cavity, is a curved piece of metal that directs air more evenly to the vents. That's the only difference between the factory installed fresh air vent openings and my modification.
Okay, how to install the vents.
1. Remove your car's dash. Yes, I know that's hard, but you need the space to make your marks and drill your holes. I'm lucky in that my dash has not yet been installed and I can make all my modifications before actually installing it.
2. Identify the area where you want to drill your holes. I used a 2-1/2" hole saw with a small 3/8" pilot drill bit in its center. After marking the centers of where I wanted to drill both my holes, I drilled a 1/8" pilot hole.
3. Placing the hole saw's pilot drill bit on the small guide hole, I simply drilled out the 2-1/2" holes. My hole saw grabs the cut-out piece and removes it as it is brought back through the opening. If the piece of metal that you cut out falls into the air cavity, a 'magnet-on-a-stick' will easily retrieve it through the air grille opening in the cowl.
6. Tossing the Vent Estucheon in my extra parts bin, I kept the R/H and L/H face air vents themselves. Turning the vents sideways, the snap right into place in a '67 dash's radio opening.
7. All that remains is to connect the vent tubes to the back of the vents when the dash is installed and, VOILA, face-level fresh air vents in Jerri's '67 dash.