superhatchbackbros

as the title says lookin to do a mini swap in my 89 boosted ef hatch. i currently boosted on a d16y7 and im looking to do a mini swap.. im asking what head is better to use all around d16z6 or a d16y8? and also the ups and downs of each head.. thanks in advanced people..

streetjdmrex

y8, combustion chamber is bigger than the z6

1991hb

Also, you will probably find a y8 with less miles

superhatchbackbros

ok thanks you.. anyone else with any more info?

loudandlow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by streetjdmrex &raquo;</TD></TR><TR><TD CLASS="quote">y8, combustion chamber is bigger than the z6</TD></TR></TABLE>

i thought the y8 on the mini me raised the compression more then the z6 head???

can anyone back me up or shoot me down on this???

loudandlow

"So compression...an a6 block and pistons with a z6 head nets a low to mid 10:1 compression ratio (CR). The y8 head mated to the same block/pistons comes out to be high 10, low 11:1 CR. The stock CR on a d16a6 is 9.1:1 so as you can see, it's a significant increase, as far as CR goes."

guess where i got that info.... THE FAQ

njn63

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by streetjdmrex &raquo;</TD></TR><TR><TD CLASS="quote">y8, combustion chamber is bigger than the z6</TD></TR></TABLE>

Other way around. y8 is smaller combustion chamber (but better designed IMO).

If you have a turbo car though, the money is better spent on a set of rods/pistons. The head doesn't breathe much better and is just a cheap way to get higher compression.

superhatchbackbros

guys im working with a d16y7 block with 40xxx on it and wanted to know what head made less compression and which was better.

njn63

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by superhatchbackbros &raquo;</TD></TR><TR><TD CLASS="quote">guys im working with a d16y7 block with 40xxx on it and wanted to know what head made less compression and which was better. </TD></TR></TABLE>

z6 is lower compression.

As far as which one is 'better', they're about equal. The ports are "better" on the z6 but the combustion chamber is better on the y8.

Either way, as I said in my last post, the money can be better put in other areas on a boosted motor. The y7 head is not hurting you in any way really and rods/pistons could allow you to make some nice numbers.

superhatchbackbros

ok so a z6 head on the y7 block is lower comperssion but the y8 has a better combustion chamber? what would u go with? personaly

gator88

incase you do want a y8 head though, i am in PA, check my sig out.

Now i have heard that the z6 is better for NA but the y8 is better for FI because of port design, that the y8 has tumble ports or something. I AM NOT stating this as info because i dont want to misinform, i am merely asking those who truly know the difference in the flow characteristics. I am just asking this question to help me and the OP. Thanks

1991civicsi

Y8 OBD2
Z6 OBD1

njn63

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1991civicsi &raquo;</TD></TR><TR><TD CLASS="quote">Y8 OBD2
Z6 OBD1</TD></TR></TABLE>

Doesn't matter, sensors are all the same. Only difference is distributor bolt pattern (z6 is unique, y8 is same as all OBD1 non-vtec motors)

superhatchbackbros

i know y8 obd2 z6 obd1 im saying whats going to make me have lower compression.. and what head is beter. im tkaing the y8 is best to go with??

89efDUSTY

iTrader: (4)

If you are worried about the compression difference in regards to your boosting, its not "that" big of a difference. I personally like the y8, I love the IM plenums compared to the z6. P.S. if you go y8 head, I have a y8 dizzy with the a6 plugs spliced FS.

superhatchbackbros

a i have a z6 IM imma put on the y8 i kinda like it better. but far as the dizzy i already have one and i have the real obd0-0bd1 conversion harness and i know the y8 is obd2 bu tim just going to depin and repin thanks neways.