fkncivic

building an all motor z6 and am wanting to know what oem piston combination i can use to get a decent compression boost, wanting to go around 11.5 : 1.... was going to try b7 pistons but i am told that they wont work. also wondering about the d16a1 pistons from the 86-87 teg and if those will work fine and give a nice high compression.


Modified by fkncivic at 8:10 AM 9/18/2008

-=Zeqs=-

iTrader: (1)

I can't remember exactly what it yields, but some ppl use D16A6 pistons. I believe it's like...11:1 though?

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

SOHCinWA

Alot of people use the p29 pistons to bump compression.

0Bisimoto

SOHCinWA is correct. In addition, when you are ready, contact us for some cams, intake heat shielding gaskets, cam gears, and springs for your build...long live the D!

Aquafina

iTrader: (3)

B7's will work. Sit roughly .028" above deck, this will vary with each build so make sure to check it on yours.

fkncivic

if they sit above the deck wont that hit the head?

fkncivic

i think im gonna end up using the pg6 pistons, they give slightly lower compression than the p29 and should keep me below the race gas threshold.

dirtyharryhatch

how much will this make to the wheels like 130 or something?

Aquafina

iTrader: (3)

Thats why you need to check clearances. I'd rather have pistons above deck than below.

SOHCinWA

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Thats why you need to check clearances. I'd rather have pistons above deck than below.</TD></TR></TABLE>

x2

fkncivic

yea but if you have pistons sticking out of the deck and are revving high wont you smack valves?

SMSP

Not if you check clearances first.

Here's my build https://honda-tech.com/zerothread?id=1420377

and final dyno https://honda-tech.com/zerothread?id=1739065

BTW, that prototype header is for sale by a buddy of mine who purchased it before I sold the car.

I see this car every day and the engines still running in top form with around 35k on her.

d15Beta

ive run as much as .112" above deck LOL but with a .060" gasket..

so thats roughly .052" above deck (with gasket)


(dont do this , it was just an experiment by shade tree me LOL )

above deck is fine like aqua mentioned..

nothing beats proper clearance, attention to detail and care in the build..
lose one of those details
and even a stock rebuild will blow up..

i suggest reading dave/smsp's d16 build , has good info's and alot of details on what made power, and various changes..

go from there.. and then choices for aftermarket parts, nearly endless..

Bisimoto has most of the things u need

go a step higher with either Bisimoto or SMSP header

fkncivic

has anyone ever used to pg6 pistons? will they be a direct fit in the z6?

1.5Slowmatic

DO NOT USE THEM. you will have issues with those pistons. P29's are ok but they leave alot to be desired as far as overall performance. You get higher compression but thats it. The amount of quench you get with those pistons is ****, there are far better options out there. If you can find them cheap a great combo is LS rods with GX pistons. Other than that id use the PM6 pistons and mill the head. As for the b7 PM3's they are a great option also but you would have to have the valve reliefs altered because they are a non-vtec piston and you might have some clearence issues

fkncivic

what issues will i have with the pg6 pistons and please explain what you mean by "quench" with the p29 pistons .

fkncivic

Bump

fkncivic

need this info if possible, bump again!

1.5Slowmatic

the pg6's have terrible clearance even with stock cams let alone aftermarket ones. The p29's sit in the hole on a D16 block unless you zero deck them. Think of it this way,there is roughly .040 from the top of the pad on the piston to the top of the block, you have all of that extra lost compression and it creates a much higher risk of detonation even with 93 octane. A much better option is to used machined LS rods and GX pistons is going to be the best route for getting that compression and being extremley efficient

fkncivic

where do the clearance issues come from on the pg6's? they make lower compression than the p29's so is this a fitment issue on the wrist pin or what kind of clearance issue?

1.5Slowmatic

their valve relief design i believe is what causes them, lots of people have issues with them, stay away, there are far better options to get lower CR than P29's. the PM6 pistons with enlarged valve reliefs are a really good option as is the PM3 pistons but agian you need to enlarge the reliefs

fkncivic

ok but cant you just modify the valve relief on the pg6 to match the z6? not trying to beat the dead horse here just looking for options, i heard before that some people use the ef std pistons to boost compression, what is that part code?