Civic head swap
 

I have a '96 civic lx with the stock d16y7. What would be the most benificial head swap strictly for FE? I'm leaning towards the 8-valve CX head if it would work, any ideas?

It's hard to say which will be best between the HX and the 92-95 CX, but one of those.

What about the VX head? That gets way better FE than the CX, and better than the HX. I personally would go with the HX; If I can afford it I will do that swap soon. It doesnt make much sense to buy a CX head, when you can get atleast the same FE, probably better, and an extra 45 hp with the HX head.

The VX swap will give nasty compression for just a head swap, the combustion chambers are much smaller than in other heads.

And he might have the same problem with the HX head. The HX motor is just a 1.6L version of the VX.

Well, the hx head is the same cast as the y8 head, so he won't be having that issue.

W00t w00t.

swaping to a V-tec head, without the rest of the V-tec hookup is sort of... pointless?
The HX and VX heads work as 12 valve heads at low RPM and 16 valve heads at higher rpm, but they are only one piece of hard ware, there are oil lines, and solinods, and wiring, sensors and a whole branch of the cars computer that controles those extra 4 valves in the head being opened at higher engine speeds, if you don't have those other parts in the car hooked up, then it will simply work as a 12 valve head, the engine will be high tourqe at low RPM, and it's power output will peek at around 2,500 RPM, and then drop off a bit at higher engine speeds, so if you don't have a high geared tranny that is matched to the lower ideal engine speeds, it would be even more pointless to do a head swap.

Don't mean to hijack this thread but how would an HX head work on a d15b7?

Thanks!

-- Scott

That's why I'm leaning towards a CX head swap. No hardware to worry about(adding Vtec is a PITA). Is there an issue with the valve reliefs on the piston? In other words, the Y7 has 4 valves/cylinder and the CX head only has two. Would everything else just bolt up?

Well, the cx will need the ecu swapped as well, not to mention the IM and injectors and lots of that as well. I don't think anyone means just the head when they say headswap, they mean the head and the things needed to make the car run properly.

There should not be an issue with the piston relief, the 92-95 cx had 4 valve relief pistons anyway (saved money on production I guess).

What about the CX/VX tranny (3.25 FD)? Is that "swappable" to a 96-00? That should get me some decent gains by itself.

The CX/VX transmission will fit and work and all that good stuff, the gearing is very nice, so yeah, go for it. Where do you live? If you're not in a hurry I have a CX tranny kicking around in my basement I could send out to you when I go home for winter break.

I would guess the HX/VX would show similar improvement. With the HX you would stay OBDII though, and wouldn't need to worry about passing emissions (In my county they get pissy about that). The CX would be a good option if you just want a straight swap, but I wouldn't expect a large improvement.

The tranny would probably be your biggest improvement. And maybe a set of HX wheels (won't do too much, but I like pushing HX/VX wheels).