sub2010ss, not so sure that would be a great idea, and here is my reasoning. When speakers are mounted, not only does the front disperse sound, but also the back of the speaker. And anything that would upset that rear dispersion will change the sound as well. Some speaker designs even use that back firing sound to assist with the output of the front to boost bass and such. Ported speakers are that way. So with an engine offering contrasting noise when running would make the sound suspect in my opinion. Then there is both the heat and obvious vibrations to deal with. I think I would look for a more subtle area to mount your speakers. But that is just my opinion. And yes I have built many speaker cabinets myself... :noidea: