91civicEX

i am going to be doing a mini me swap and i am having a hard time deciding which head to use. the z6 head will be cheaper and easier to find. but the Y8 head will yeild better compresion and better flow. i will try to run a z6 cam too on whichever head i get so the vtec crossover will be calibrated correctly. i will convert to obd1 so the z6 dist will prolly not fit on the Y8 head. this is all going on a 1.5 block. has anyone experienced both or knows which one is better? im looking for more power.

Broken Gearbox

i think the Z6 head flows better but the y8 has a better camshaft...if you could find a z6 for cheap i would grab that

91civicEX

the main thing i am concerned about is how much power will i be loosing by going with the lower compression z6.

uszcrx

go for the y8 and use the y8 Intake manifold and they are newer :-) better flow through that manifold and i think better compression

Broken Gearbox

will if u do get the z6 just get the EX headgasket that should bump up the CR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by uszcrx &raquo;</TD></TR><TR><TD CLASS="quote">go for the y8 and use the y8 Intake manifold and they are newer :-) better flow through that manifold and i think better compression</TD></TR></TABLE>

yea definately get the Y8 intake manifold...

STIBungy

So what are the hp/torque yields on a minime?

fastcrxsi90

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91civicLX &raquo;</TD></TR><TR><TD CLASS="quote">i will convert to obd1 so the z6 dist will prolly not fit on the Y8 head. this is all going on a 1.5 block. has anyone experienced both or knows which one is better? im looking for more power.</TD></TR></TABLE>

i believe that you can use the Y8 dist. for obd1. so if you get the Y8 head use the Y8 dist. and p28 ecu.

the z6 has the ability to flow more on the intake side because the y8 has "staggered" (for the lack of a better word) intake ports...one port is longer than the other. if you look in the port the divider is angled instead of straight out. i believe this is supposed to help low lift swirl and emissions. and if your that worried about a half a point of compression...mill the Y8 head.

EG8R

No you can't use the Y8 dizzy. It has to be OBD0 or whatever system you are running. Well thats what I heard a few times.

RuthlessEF-9

IMO y8 head is better and z6 bottom is better
y8 bearings switch to aluminum which is not good
blew three motors (y8-y7) in less than 6months last year
i've had my z6 for almost a year now and still no problems

CRX-RX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by James. &raquo;</TD></TR><TR><TD CLASS="quote">will if u do get the z6 just get the EX headgasket that should bump up the CR</TD></TR></TABLE>
Same part # from honda for both app's. The new gasket replaced the need for the older one.

It's really all the same, you won't lose any power with the negligible compression ratio change. The main point's to be concerned with are that you use a Y8 intake manifold, and if possible the cam and ecu, or tune for the cam. The Y8's cam is more agressive, thus the higher VTEC crossover point in the Y8's.

91civicEX

i already got a z6 head. will it really choke the engine if i use my old A6 manifold on the z6 head? i want the Y8 manifold but they are hard to find. also should i get a valve job on the new head while it is off? or just slap it on and roll with it.

CRX-RX

Your best bet IMO would be to get a Y8 intake mani. The A6 doesn't have as much potential in the upper RPM. It won't "choke" out, but it won't be able to supply as much air as freely as the Y8. You will also need to get the IAC if you do use a newer mani, as well as the throttle body. Another benefit of the Y8 mani is that the throttle body is upgradeable to the B series units, where the A6 has a different bolt pattern and would require an aftermarket throttle body to increase it's size.

91civicEX

another thing. a couple months ago i replaced my intake manifold gasket. my exhaust manifold gasket has been on my car for 76k miles. i ordered new gaskets from honda but they are lagging and my bank account is having problems. what i want to know is if i am planning on replacing my intake and exhaust manifolds in the near future would it be alright to reuse my old gaskets? or should i just wait on honda and get new gaskets. ive got a new head gasket also

jung4g

ok here's what I know... with your d15 block, you should push 10.6:1 compression with the z6 head and 11.0:1 with the Y8 head. Not a big difference. Just get the cheaper one, clean it up, and then slap her on. Don't spend all the extra money on the Y8 for not a huge increase, and the a6 manifold is fine, with the kind of power we're running, the extra money for a couple hp isn't worth it.

Jung

4drEF

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by James. &raquo;</TD></TR><TR><TD CLASS="quote">will if u do get the z6 just get the EX headgasket that should bump up the CR
</TD></TR></TABLE>


For more CR use the Y8 head gasket. It is the thinest one for the SOHC's.

If you are going to stay OBD-0 the Y8 is your best choice as far as the dizzy goes. The A6 dizzy will bolt right on with no mods.

If you go with an OBD-1 conversion either head will work fine with the P28 ECU. For the Z6 head just use the Z6 dizzy and for the Y8 use the OBD-1 NON-Z6 dizzy. I also here that the OBD-2 Y8 dizzy will work, but you need the OBD-2 dizzy plug (no big deal).

The combustion chamber flows better on the Y8 head. Compare it to the ITR head... basically the same square design.


Y8 intake manifold

Broken Gearbox

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4drEF &raquo;</TD></TR><TR><TD CLASS="quote">


For more CR use the Y8 head gasket. It is the thinest one for the SOHC's.

If you are going to stay OBD-0 the Y8 is your best choice as far as the dizzy goes. The A6 dizzy will bolt right on with no mods.

If you go with an OBD-1 conversion either head will work fine with the P28 ECU. For the Z6 head just use the Z6 dizzy and for the Y8 use the OBD-1 NON-Z6 dizzy. I also here that the OBD-2 Y8 dizzy will work, but you need the OBD-2 dizzy plug (no big deal).

The combustion chamber flows better on the Y8 head. Compare it to the ITR head... basically the same square design.


Y8 intake manifold </TD></TR></TABLE>

umm the 96-00 EX models come with a D16Y8.

4drEF

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by James. &raquo;</TD></TR><TR><TD CLASS="quote">
umm the 96-00 EX models come with a D16Y8. </TD></TR></TABLE>

So what is your point? 88~91 EX's came with a D16A6. Maybe we should use a gasket from one of those. It fits your "just get the EX headgasket " idea. It's not my fault you didn't state what year you were talking about in your original post.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by James. &raquo;</TD></TR><TR><TD CLASS="quote">
will if u do get the z6 just get the EX headgasket that should bump up the CR </TD></TR></TABLE>


You talk about a Z6 and most people will relate that to the EG (92~95). Then you talk about an EX. Well damn... must be talking about EG's still.

91civicEX

looks like for now ill have my A6 manifold, my old header a z6 head and an obd1 EF. do i have to wait for my new intake manifold and exhaust manifold gaskets to come from honda? i have the head gasket and im tired of waitin on honda to ship em.

euclidEH3

how bad off are the old gaskets?
If you are going to replace the intake manifold soon with a Y8 or Z6, If the old gasket isnt torn, just wipe it off really well, clean off the mating surface on the head, and coat the entire intake gsket with a layer of honda bond. It might not last as long, but will hold till you get your new intake mani.
Ive re-used the metal exhast manifold gaskets before, Its not really the right way to do it, but in a pinch it can be done. As long as you know there might be issues with leaking and are willing to take the chance, go for it.