Hemi Question.....

[MistyEyes]

I know a Hemi is Hemispherical.....but please can someone tell me the benifits of having it that way....I understand at least part of it is power....but I would really love to know, it's a beautiful engine.....also, is there a way to detail it without doing it all by hand, I have been doing it by hand all along because I was told it would get water in the deep well ports for the spark plugs if I pressure wash it....could I use plastic and duct tape to tape it off so it could be sprayed. around them....?? Thanks for your expert advise ahead of time......Misty......