im doing a mini-me for a friend and was wondering what is the comp.. w/the z6 head on the a6 block w/1st gen d16a1 pistons?

 

it's a tad high running but use Zeal's comp calc


unless i put it in wrong looks around 9.7:1
http://www.zealautowerks.com/dseries.html

 

i think you calculated something wrong...using a z6 head gasket, im comin up with 15.39:1..i knew it was gonna be really high...but thats not gonna run on anything under rocket fuel

 

woops, scratch that, i did something wrong...i didn't see he was using an A6 block...he said mini-me so i assumed he was using the d15 block and crank, as that is the typical setup

 

12.03 : 1.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tippyman &raquo;</TD></TR><TR><TD CLASS="quote">12.03 : 1.</TD></TR></TABLE>
that is what i get with 88-89 D16A1 pistons, D16Z6 head and D16Z6 gasket - 86-87 D16A1 pistons will be lower or about 11.7:1

 

is that to high of a comp... to drive on the street.

 

as long as u have a sunoco around with 94 octane, u should be okay..thats gettin close tho, but you could always throw an A6 gasket on there to lower it a little bit

 

Tuning will be key.

 

where i live we have a gas station and it sells 93

 

Ask in the all-motor forum. They would be more familiar with the limits of pump gas on high comp motors.

 

yeah i mite go wit da a6 head gasket then if it lowers da copm... a lil bit. jus 2 b safe. n should i use the a1 rods as well?

 

every d series rod is exactly the same length. 5.394 i believe...but thats your choice, im not sure what the strongest rod is, ive heard dohc zc rods are one of the best...but rod choice won't make any sort of compression difference

 

right, all the d16 rods are the same length, I'd just find some used 88-89 integra pistons that had rods already attatched, save the time and $ of getting them pressed on to something else.

On a side note, kick ***, my quote is in somebody's signature! haha, I said antichrist

 

how can all the dseries rods be the same where do u get the 1.5 the pistons are the same in diameter but the stroke is what make the 1.5 and 1.6.

 

Rod length doesn't determine stroke, the crank does.

The Integra rods are not necessarily stronger, I've had a couple sets of PM7s from integras and ZCs, and they aren't much different. AFAIK, the rumour is that the teg rods are beefier, but the material isn't as good. Doesn't matter anyway, just use ARP rod bolts and maybe shot peen the rods and you're ready to go.

The compression is fine to run on pump gas and on the street IF YOU TUNE IT. You should be looking at low 12s, as said above. I've run, and I'm running again, 12.6:1 on pump gas in an A6/Y8 mini-me, it's fine. If you try to run it on a stock ECU or map, you're gonna break ring lands at the very least. Don't just throw it in and try to run it on a stock P28, I won't even mention not converting to OBD1 and what that comes with.

Make sure when you get the pistons, if you get them from an integra, that they are PM7s (or P29 if it's been rebuilt, unlikely). The 86-87 D16A1 used different pistons (pg6 or something) which aren't going to work. They do give the same compression, but the dome is different and you will run into valve clearance problems unless you have them fly-cut.

PM7 FTW:

 

like said above me, compression ratios have nothing to do with rod lenght... compression ratio is a ratio of bottom dead center cylinder volume (the first number) compared to the top dead center cylinder volume (the second number of the :1)...this is all determined by the crankshaft...im not hear to teach a physics lesson, haha, just thought id throw some info out there for the misinformed

 

ok corrrect me if im wrong a a6 block with z6 head and z6 gasket lands at 9.9 comp but with a a6 gasket it will land at like 9.7, right now im running a zc/y8&lt;&lt;&lt;pm7 pistons and my comp is like 11.5 on pump gas 91 octane and i'm smoking b series

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ALL-MoToR559 &raquo;</TD></TR><TR><TD CLASS="quote">ok corrrect me if im wrong a a6 block with z6 head and z6 gasket lands at 9.9 comp but with a a6 gasket it will land at like 9.7, right now im running a zc/y8&lt;&lt;&lt;pm7 pistons and my comp is like 11.5 on pump gas 91 octane and i'm smoking b series</TD></TR></TABLE>

You're wrong.


You're saying you have a ZC block, I'll assume SOHC non-VTEC ZC, and Y8 head with PM7s. That's the same as I have basically, you're running 12.6:1 compression. Keep running around on 91 and you won't be smoking anything (your ringlands are probably already gone), where do you get that number (CR) from?

 

a mechanic told me..but i'm not sure what head-gasket im using...i live in fresno and all i see around is 91 octane..but how fast are you running

 

as far as i know, there is not head gasket out there thick enough to bump you a whole factor of 1 on your compression ratio...that would be like 5 mills thick lol...i think your mechanic is an idiot

 

Yeah I can't come up with a feasible (nevermind likely) combo of parts to get that CR... there's BS somewhere.

 

for your information my mechanic is like one of the best but i was just adding myself because the y8 headgasket is much thicker than the zc, I was just saying but thanks anyways for your output so DOWNEST how fast are you running?

 

i could be wrong, but is a zc headgasket not the same as an a6 which is on of the thickest d series gaskets?

 

i believe the thickest is a d16y8