huntarrr

searched but didn't find any info regarding my specific set-up.

what kind of compression will these pistons yield in a y7/y8 mini-me?

could I use the y7 rods or should i swap in the a6 (or y8 or any other) rods?

anyone ever do this? and if so, what kind of numbers are you pushing?

B18C5-EH2

Those pistons are not ones I recommend with a Y8 head because the CR will be crazy high (over 12:1) for cast pistons. the Y8 head has small combustion chambers which make the CR higher than any other D series engine.

I'd probably at most go with the 86-87 Integra baby dome pistons.

I can try and punch the numbers into a CR calculator to see what the supposed Cr would be.

Also Y7 bottom ends are pretty notorious for being weak all around. I'd be looking for a D16Z6, D16Y8, or D16A6 bottom end (or complete VTEC engine to begin with) to do any builds on, especially with revs.

huntarrr

^thanks for the info

I started with a stock y8 in my 98 ex, but it got hydrolocked about a month ago and my finances opted for the most cost effective way to get my car running, so i had to go with the y7/y8 mini me...

is there any difference between the y7 and y8 blocks besides the pistons? i thought the rod lengths were the same.. is the crank weaker in the y7?

i just want a mildly higher compression to boost the power.. over 12:1 would be too much.. maybe around 11 or so...

huntarrr

anyone else? what pistons are good for around 11:1 CR?

Blind-Fashion

lol... that guy new absolutly nothing. the a6 pistons will put you a little over 10.4:1 compresion. and the d16y7 bottom end is just as strong as any other d16 bottom end, its the d15(b2, b7 , b8) bottem ends that are shitty as ****. dont listen to him.

if you have any more quesitons feel free to pm me.

-Josh


http://www.knology.net/~jediklc/D.htm

Blind-Fashion

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">Those pistons are not ones I recommend with a Y8 head because the CR will be crazy high (over 12:1) for cast pistons. the Y8 head has small combustion chambers which make the CR higher than any other D series engine.

I'd probably at most go with the 86-87 Integra baby dome pistons.

I can try and punch the numbers into a CR calculator to see what the supposed Cr would be.

Also Y7 bottom ends are pretty notorious for being weak all around. I'd be looking for a D16Z6, D16Y8, or D16A6 bottom end (or complete VTEC engine to begin with) to do any builds on, especially with revs.</TD></TR></TABLE>


and with these "baby dome pistons" he is talking about, it yeilds more then 12-1

jerbear!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blind Fashion &raquo;</TD></TR><TR><TD CLASS="quote">lol... that guy new absolutly nothing. the a6 pistons will put you a little over 10.4:1 compresion. and the d16y7 bottom end is just as strong as any other d16 bottom end, its the d15(b2, b7 , b8) bottem ends that are shitty as ****. dont listen to him.

if you have any more quesitons feel free to pm me.

-Josh


http://www.knology.net/~jediklc/D.htm

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

did this guy just say Tom was wrong???

Blind-Fashion

sorry to bring the bad news, but yeah, i have built a few all motor d series.. and used 88-89 zc pistons and 86-87's and also had an a6 mini me. and currently have a y7 block and its COMPLETLY IDENTICAL to a y8 block (internaly except pistons)....


He may know his ****, but its not about d series. maybe he just heard wrong or something. but thats not my problem, i'm helping out with legit FIRST HAND experience.


-Josh

Blind-Fashion

12.6 would be the compresion with a y8 head gasket and the "baby dome" pistons.

not putting this guy down, just posting what i have used.

and you can use any of the 1.6 rods. just make sure you read the rod number and get the proper bearing, and of course, plastigauge it out.

-Josh

civic-4-ges

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">Also Y7 bottom ends are pretty notorious for being weak all around. </TD></TR></TABLE>

I would love you to point out any difference between the two bottom ends(Y7 and Y8), other than the pistons themselves!

civic-4-ges

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by soccaian &raquo;</TD></TR><TR><TD CLASS="quote">teehee... this is funny

peep the sig thread starter..</TD></TR></TABLE>

Im going back to the d-series site....

B18C5-EH2

When I said the Y7 bottom ends are junk it's only because I've known like 3 different people here in GA who had theirs blow up shortly after they did their VTEC head swaps. Perhaps it's some coincidence, so I apologize if I was giving misinfo.

I'm not one to randomly blurt **** out, so I do take offense to someone saying I don't know **** about the D-Series.

I'm busy at work during the day, or else I'd have double checked the CR ratios for various pistons. I didn't see anyone else jumping to even try to help the guy, so cut me some ******* slack bro.

As far as me not knowing **** about the D-Series, I've built my own 11:1CR D16A6 that runs flawlessly and burns no oil, doesn't smoke, etc:







So take it for what it's worth. Also if you'd re-read my original post I stated:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by me &raquo;</TD></TR><TR><TD CLASS="quote">I'd probably at MOST go with the baby dome 86-87 Integra pistons...</TD></TR></TABLE>

Yeah so why the hell are you ripping into me so hard then?

Again it was a simple matter of me not looking up CR specs, so if you want to crucify me then so be it.

B18C5-EH2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Blind Fashion &raquo;</TD></TR><TR><TD CLASS="quote">
and with these "baby dome pistons" he is talking about, it yeilds more then 12-1</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinf Fashion &raquo;</TD></TR><TR><TD CLASS="quote">12.6 would be the compresion with a y8 head gasket and the "baby dome" pistons.</TD></TR></TABLE>

According to your CR chart you linked, the CR for the 86-87 Integra pistons in an otherwise stock D16Y8 should be closer to 12.2:1, which I agree is a bit much. again remember I stated at MOST, not "yeah definately get those and only those..."

Here's the values I used:

Bore: 75mm
Stroke: 90mm
Combustion chamber volume: 32.8 (D16Y8)
Piston dome displacement: +1.5 (86-87 Teggy)
Head gasket - .037 (Stock metal 92-00 VTEc gasket)
Piston-to-deck - 0 (86-87 Integra)

Did I punch something in wrong?

stevel

anyone ever use an A6 bottom end or a A6 pistons in a bottom end with a Z6 or Y8 head? I'm gonna be doing this and am just concerned about the valve reliefs not lining up well and not being deep enough. The head will be shaved .025" and a bigger cam (not that big, 11.4mm lift) so I'm worred about valve to piston contact. I will clay most likely but no one I've found has even done this. Just looking for someone that has experience with this setup.

s

civic-4-ges

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah so why the hell are you ripping into me so hard then?


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

Dude..I was not ripping into you, just wanted to know why someone would make a distinction between y7 and y8 blocks, thats all

Now to go and make a distinction between obd1 and obd2 D16 blocks, thats another story!

Redline96LX

Seriously, watch your **** with the y7 block. I have a d16y7 engine, if you get pictures of its connecting rods, they are teeny, and "pencil thin." They are really not meant for high compression or turbo, although this block will take 7lbs of boost no problem, i can't comment on what 12:1 comp will do.

civic-4-ges

11.5:1 c/r works fine so far

B18C5-EH2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline96LX &raquo;</TD></TR><TR><TD CLASS="quote">Seriously, watch your **** with the y7 block. I have a d16y7 engine, if you get pictures of its connecting rods, they are teeny, and "pencil thin." They are really not meant for high compression or turbo, although this block will take 7lbs of boost no problem, i can't comment on what 12:1 comp will do.</TD></TR></TABLE>

So are the rods in fact different for certain on the Y6 and Y7?

I'd like some clarity on this issue since like 3 of the Y7 VTECs I've known blew up due to bottom end issues like rod bolts, etc.

Blind-Fashion

nope, they are the same. i have a set sitting in my garage, they are the same as Z6's... and sorry for trying to rape you, just wasnt in to good of a mood yesterday.. and when i did the compression calc with the baby dome's, i used the 2 layer y8 gasket, thats why it showed a little higher.

-Sorry again
Josh

huntarrr

according to http://www.knology.net/~jediklc/D.htm the rods for the y7 and y8 have the same stroke, rod length, rod:stroke ratio, and deck height. in what aspects are the y7 and y8 rods different?


D16A1,A6,Z6,Y5,Y7,Y8 90mm 137mm 1.52 212mm

B18C5-EH2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vsm98civic &raquo;</TD></TR><TR><TD CLASS="quote">according to http://www.knology.net/~jediklc/D.htm the rods for the y7 and y8 have the same stroke, rod length, rod:stroke ratio, and deck height. in what aspects are the y7 and y8 rods different?


D16A1,A6,Z6,Y5,Y7,Y8 90mm 137mm 1.52 212mm </TD></TR></TABLE>

Rod length and all are the same, but the thicknesses can vary as can the quality of the studs/bolts for the rods.

Example?

D16A1 rods are beefier than other D series rods. They are thicker.

But then again, I don't know **** about SOHC engines...

civic-4-ges

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">D16A1 rods are beefier than other D series rods. They are thicker.

But then again, I don't know **** about SOHC engines...

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


Thicker rods...but weaker material

capbyrd

the problems with the rod bolts and stuff breaking might not necessarily be because of the weakness of the bottom end but because of some one over revving their engine. y7's just arent meant to rev regularly into vtec range. i have one and i do it all the time but when i do my mini-me, ill be goin with a6 pistons, aftermarket rods (if i get them cheap enough) and arp bolts. just dont take chances

d15Beta

not to jack the thread.. but i too nid sum help

my engine is a d16a6 non vtec im planning to install sum dome pistons on it.. but i dont have a clue wat cr it would yield... the pistons will be coming from a 1200cc carbed engine.. they are the same bore as the d16a6 but only the stroke is diff. my prob is that i canot find any details and or specs on the said 1200cc engine online.. is there a way i can measure it or sumthing?

though sum1 told me it would prolly yield about 12.5:1 to 13:1 cr
i dont know if this will have any downside on the reliability although i get 96octane on pump gas

tnx anyways

creechrr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevel &raquo;</TD></TR><TR><TD CLASS="quote">anyone ever use an A6 bottom end or a A6 pistons in a bottom end with a Z6 or Y8 head? I'm gonna be doing this and am just concerned about the valve reliefs not lining up well and not being deep enough. The head will be shaved .025" and a bigger cam (not that big, 11.4mm lift) so I'm worred about valve to piston contact. I will clay most likely but no one I've found has even done this. Just looking for someone that has experience with this setup.

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

Z6 head/block with A6 piston right here. I'm also running a Zex cam. No problem with valve reliefs.