|The MGA With An Attitude
HEATER AIR HOSE Bending And Stretching - HR-109
The MGA heater setup includes two small air hoses to direct air to the demister vents, and some larger 4-inch diameter hoses for air intake up front. If you order replacement hoses, they come compressed on length and need to be stretched out longer in the process of bending to fit. The material is thin aluminum with black paper inside and outside, and convoluted so it can be stretched and bent.
The smaller hoses are easily formed and stretched by hand. Essentially, just pull on the hose when you bend it and it will stretch. You need to be careful not to smash the ends of the duct out of round. For this you can put something inside the ends to prevent it from collapsing. The original car setup has a metal end connector on the heater box, and a thick rubber bushing on the demister duct that may be used for this purpose.
There is a 4-inch air duct running from the heater box forward to the radiator mount pipe connector. And another 4-inch duct forward from there to just inside the grille, along with a mirror image duct on the other side to bring cool air to the carburetors. Being larger, these are bit more difficult to stretch and bend but the same principal applies, pull while bending to get it to stretch. I like to lay it across my chest and pullback on both sides. Rotate the pipe and repeat as needed for more stretching.
For the larger hoses, Jim Cheatham in Amelia, VA, USA suggests using a 3-inch PVC female adapter to put into the end to allow bending the hose without distorting it.