my 96 ex originally had the y8 engine in it and i blew that motor, well i get a new engine and this guy that claims he was a honda mechanic for 17 years says that he has the same exact motor that i have and wants to sell it to me for $400. So i buy it. well my dad goes down and gets it and brings it back home and i look it over and its a y7 engine. now, i have 3 questions. 1) can i put my y8 head on it in order for it to be relatively stock other than compression? 2) if i dont put the head on it, do i need a new wire harness to compensate? AND 3) (giving that i still dont put the y8 head on) i would also need a new ECU for the y7 correct? thank you for your time and help, Kyle


PS. kind of need to know soon as i will be leaving for 5 years for the army on the 18th of Nov.

 

they are relativly the same setup. the y8 is vtec and the y7 isn't. the y8 head will fit on the y7 block, just make sure you put the y8 intake manifold on to make it easier. if you were not to change the head, the y7 intake manifold has sensors in different locations so you may have to lenghing some connections to reach sensors, and yes the y8 ecu will power the y7, you just won't have vtec with the y7 setup without the y8 head. you best bet is to do a complete head swap to the y7, put the y8 head intake manifold and exhaust manifold onto the y7 and you will pretty much be the same as before hand. keep in mind that mostly all dseries motors, parts are interchangable, all b series motors, parts will interchange and so on...

 

If you run the Y7 head the car will bog at 5500RPM (when VTEC kicks in) because the head lacks VTEC. If you use the Y7 head you will need the Y7 ECU.

 

so you can run a y8 head on a y7 bottom with an y7 ecu and harness? I came across and issue today that I'm trying g to figure out..

 

You can. But, if you run the y 8 head, you'll need the y8 harness to power the VTEC valve. You can run the y8 intake manifold on the y7 long block (engine block and head), but will need the longer y8 throttle cable. The y7 wiring harness is designed for the y7 engine, and won't have the needed wiring for the y8 VTEC valve.
I only mention some of this, because my son's 98 Civic has a y7 engine, with a y8 intake manifold on it, and it runs pretty decent, but he's also running the y7 injectors. He did have to hunt down the y8 throttle body and longer throttle cable to be able to use the y8 intake manifold (the TB works backwards on the y8).
Just so you know, the y8 is basically the same engine as the y7 (bottom ends are the exact same), but without the VTEC system (mostly in the head).