learn your engine codes. d15y7 b16a2 b18b5
the way i cheat (i've not heard anyone endorse something else, but then I've not done much research):
a "b" at the start of the code means DOHC. a "d" is for SOHC. think of how the letter is drawn, and it sorta makes sense.
the pair of numbers is then decaliters (?)
d15y7 = SOHC 1.5L PFI (102hp)
b16a2 = DOHC 1.6L VTEC (160hp)
h22a1 = SOHC? 2.2L VTEC (190hp)
ok, so it's not a perfect system

( IMHO, D-series motors should be the DOHC ones. but, i guess then you'd need an S-series ;-) ) LOL