I've got an 89 civic Si and a VJ14 turbo off my 323GTX. I may get some cores from a talon and tig weld them into an intercooler and use that. Unfortunately I have a leaky cylinder. 50PSI on #3 so it needs to be fixed before I add boost. I think the headgasket is leaking. During a leakdown I can't figure out where the air is coming from - sounds like it's coming up the oil journal for the head. I just rebuilt it 7000km ago. The head was really rough and I have a feeling it is warped. Re-using bolts prolly didn't help either.

So now that you know my life story... This leads me to want to replace the head. I have a line on a Z6 head with bent valves as well as a Y8 from a junkyard for $100. Any opinions on whether I should get another A6 or swap in a Z6 or Y? I can ghettodyne the ECU and hack it up to run a vtec solenoid. I'd rather not increase the CR any.

-Michael

 

in my opinion another A6 head should be the easiest choice for you.
With either VTEC heads you are increasing static compression, and as i have heard (no personal experiences with minime's) timing is always a problem, which is not a good idea on a boosted engine.
stan

 

I think the previous owner put in higher compression (A2???) pistons so upping the CR even more would be really bad. I'm considering swapping the pistons and getting some B series rods while I have the head off.

As for the head, it has to be changed anyway. The price difference is negligible. With the correct pistons in the motor does anyone know how much a Z6 head would increase the CR? I suppose the cheap solution to this is to get a thicker head gasket.

-Michael

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hackish &raquo;</TD></TR><TR><TD CLASS="quote">I think the previous owner put in higher compression (A2???) pistons so upping the CR even more would be really bad. I'm considering swapping the pistons and getting some B series rods while I have the head off.

As for the head, it has to be changed anyway. The price difference is negligible. With the correct pistons in the motor does anyone know how much a Z6 head would increase the CR? I suppose the cheap solution to this is to get a thicker head gasket.

-Michael</TD></TR></TABLE>
sounds like P29 from a D16A1, that's pretty high as is, with a Z6 or Y8 head you are looking at well over 13:1...
Keep in mind B18 rods will only work with aftermarket pistons, utilizing floating wrist pins.
Unless you REALLY want VTEC A6 head is plenty good for FI, with a cheap port you will be happy.
stan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hackish &raquo;</TD></TR><TR><TD CLASS="quote">I think the previous owner put in higher compression (A2???) pistons so upping the CR even more would be really bad. I'm considering swapping the pistons and getting some B series rods while I have the head off.

As for the head, it has to be changed anyway. The price difference is negligible. With the correct pistons in the motor does anyone know how much a Z6 head would increase the CR? I suppose the cheap solution to this is to get a thicker head gasket.

-Michael</TD></TR></TABLE>

This might help with your compression question
http://www.knology.net/~jediklc/D.htm

Let me know what you plan on doing with your setup, I'm trying to figure out a F/I setup for my 11:1 compression d16a6

 

Damn, that's one handy site. I can't remember what was stamped on the piston tops. Vaguely I remember they were PM7 and to quote the previous owner "yo that engine is fully built with JDM pistons" People who've driven it do say it's got a little more "zing" than normal. DSPO also claimed that the head came from a 1992 del sol but people who know hondas more than me say it's an A6 head. No idea how to verify this.

From what I can see it looks like a ZC head would be a good combination with the rest of the stuff being A6 dropping the CR to 8.25:1. My only concern is how well the cast pistons and weeny rods would hold up to the extra boost

About swapping in some B series rods, I didn't know that you had to get aftermarket pistons. The few people I've asked claim they're bolt on. I wonder if they're bolt on with B series pistons or if they are even compatable...

-Michael

 

Check this out, this might just be the ticket for you, read all the info carefully as the combo in this thread gives around 8:1 with stock block and head, depending on the head used.
Stan