On 7/18/2010, Bill Pederson wrote:
>"I've considered covering the underside of the bonnet with an insulating pad. I wonder if you've heard of that, tried it yourself, or could express some opinion on it".

This was never standard issue on any MGA. These cars were built to be light weight sports cars. Adding the weight of insulation pad in the bonnet would likely offset the weight advantage of the aluminum skin. However, I can understand the desire to "modernize" the old car for better creature comfort during casual touring, at some expense to ultimate performance.

If you do this, be sure to use high temperature adhesive, as the bonnet is not far from the exhaust manifold. Glue on the top side of an insulation pad should be better protected form engine heat, but ordinary weather strip adhesive (rubber cement) might not cut it.

In my car I have added some carpet padding on the floor and in the rear tunnel area. I have also installed the under dash insulation pad originally intended for use only in the Coupe. I can HIGHLY recommend the under dash pad for both sound deadening and thermal insulation, phenomenally effective on both counts. After last body off repaint in 2008, having confirmed the good effects of the under dash pad, I bought an under bonnet pad, thinking it might cut down a bit on tappet noise. It must not be very high priority in my life, because I never got around to installing it. I recon the under dash pad is much more effective at over all noise reduction.

Also note that carpeting the battery cover helps some with road noise and exhaust noise suppression and thermal insulation (especially in cold weather). Carpeting the boot can also suppress road noise a little, but is MUCH more effective at deadening noise from the boot if you leave anything sitting loose in there, like my scissors jack and traveling tool box for instance. Loud thumping noises from the loose tool box virtually disappear when it is sitting on carpet.