Im going to buy this milled head off some guy and i just needed some info. Its a D16A6 head, and I have a SOHC ZC. The guy said its milled .002 and i was just wondering how much compression I'd have if i put it on my SOHC ZC. Also, how much will it be if i put that head on, plus a Y8 head gasket? Milled .002, does that sound right? Shouldnt it be .020? This is the exact quote he wrote

"D16A6 Bare Head Milled to minimum specification height requirement...
Head is milled to minimun height requirement '.002in'' to increase compression, which will increase hp. valves are all seated for good compression. "

 

.002 2 thousandths off tha head isnt much i dont think you will see much of a raise in compression it will probly b around stock if not a little higher. i might b wrong ???

 

I see, I'll double check tomorrow. Even if its barely milled, im getting it dirt cheap, and i was looking for a spare head so i wouldnt really care. But yea, anyone else have any input? Possible compression numbers? anything?

 

well im not sure if the sohc zc is any different than the d16a6...

so for a d16a6: (CR is approx.)

stock - CR=9.109:1
milled 0.002 - CR=9.146:1
milled 0.002 w/Y8 3 layer HG - CR=9.358
milled 0.020 - CR=9.498
milled 0.020 w/Y8 3 layer HG - CR=9.728
milled 0.020 w/Y8 2 layer HG - CR=9.994

 

Actually I think putting an A6 head on a SOHC ZC raises the compression quite a bit on its own. I think it has something to do with the piston dome and also the chambers?? Talk to Superhatch he knows about SOHC ZC and the compression with the A6 head.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastcrxsi90 &raquo;</TD></TR><TR><TD CLASS="quote">well im not sure if the sohc zc is any different than the d16a6...

so for a d16a6: (CR is approx.)

stock - CR=9.109:1
milled 0.002 - CR=9.146:1
milled 0.002 w/Y8 3 layer HG - CR=9.358
milled 0.020 - CR=9.498
milled 0.020 w/Y8 3 layer HG - CR=9.728
milled 0.020 w/Y8 2 layer HG - CR=9.994

</TD></TR></TABLE>

I'm running 11:1 compression with head milling I wonder what my specs are?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fastcrxsi90 &raquo;</TD></TR><TR><TD CLASS="quote">well im not sure if the sohc zc is any different than the d16a6...

so for a d16a6: (CR is approx.)

stock - CR=9.109:1
milled 0.002 - CR=9.146:1
milled 0.002 w/Y8 3 layer HG - CR=9.358
milled 0.020 - CR=9.498
milled 0.020 w/Y8 3 layer HG - CR=9.728
milled 0.020 w/Y8 2 layer HG - CR=9.994

</TD></TR></TABLE>

Thanx for the info

Ok, another question, the SOHC ZC valvetrain and D16A6 valvetrain should be interchangable right? Like the rocker arms and everything should just swap over? I just bought the head and he varified that yes, its only milled .002 but im still happy. Where can i get the Y8 2 layer head gasket btw?

 

the SOHC ZC and the D16A6 are identical engines. the pistons are the same, the heads are the same, the blocks are the same.

the sohc zc is said to have a "hot cam", but noone can prove it.

 

Sorry...but they aren't the same engines. They have different specs in the heads. The valve trains are the same but the specs of the combustion chambers are different.

I just spent the last hour searching h-t and the internet looking for a threat that included a link to a chart that had a TON of d-series specs on it. I don't know if anyone else remembers it, but it had piston to deck clearance specs, combustion chamber specs, piston specs etc. for all the sohc engines known to us Honda lovers.

Using those specs I calculated the jump in compression when using a SOHC ZC head, and a d16a6 block. Im 90% sure that it was 11.1:1 or above w/o a mill, or a thiner gasket.


Here is proof that the pistons are the same. http://www.hondaswap.com/~mike/crx/sohc_zc_int/

Im going to be taking apart my sohc zc pretty soon, and im going to do a volumetric comparison between the two combustion chambers (sohc zc vs. d16a6)

Ill keep you guys posted.

-Jake

 

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

Using those specs I calculated the jump in compression when using a SOHC ZC head, and a d16a6 block. Im 90% sure that it was 11.1:1 or above w/o a mill, or a thiner gasket.
-Jake</TD></TR></TABLE>

Wait...so If i put a D16A6 head onto my SOHC ZC block, i'll actually lost compression?