I am going to close this thread for the moment for you to do some research. There are numerous engines Honda produces and most can be used in the ek chassis.

Some of the engines you might want to look into would include:
  • b16
  • b18
  • b20
  • h22
  • k24
Run some searches for those and then send me a PM for me to reopen the thread for you to ask more questions.

Another good source to look at would be honda-tech.com and you might also consider going to forced induction (turbo etc).