Okay i've been told by so many people that you need to replace your pistons when doing an ls vtec because of the valve relief, which would make sense, but if that were true then you wouldn't be able to turbo an lsvtec bc the low compression pistons aren't domed and would hit your valves. This is just what i've been told. But my friend is doing an ls vtec with b18b block and b16a2 head. I did search but didn't find what i needed.

 

LS Pistons are flat! However if you are going to spend all that time to build an LS Vtec then put new Pistons in it!

 

You should be fine without changing the pistons, but you'll regret it if you don't, I hear. If you switch the B16 cams out for something bigger, the valve reliefs may become an issue. Clay your motor to be absolutely sure with the bigger cams.

You'll want to switch out your pistons anyway for something higher compression (N/A) or forged (forced). But no problem in leaving them stock, either, you just won't see all the power gains you could.

 

It's not mandatory, but if you plan to remain N/A than it would be a good idea... LS pistons yield a 9.2:1 compression ratio with an LS head so with a GSR head you're looking at about 9.5:1 maybe a little higher and with a B16 head about 9.3:1, give or take a couple of points...

 

Get some PCT (CTR) Pistons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LSVTEC 91 Civic &raquo;</TD></TR><TR><TD CLASS="quote">Get some PCT (CTR) Pistons. </TD></TR></TABLE>

maybe not that crazy but some ITR would be nice

depending where u live and the gas u can get as for us in california 91 octane doesn't let us go passed 12:1 compression ratio

but if u can get the p30 or 99-01 si pistons which will bring up to 13:5:1

nice

 

12:1 is doable with hondata, NOT a VAFC. you will ping, i guaruntee it.

 

i have b18a block, oem gasket, gsr head with no clearence issues

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">12:1 is doable with hondata, NOT a VAFC. you will ping, i guaruntee it.</TD></TR></TABLE>

http://www.c-speedracing.com/h...c.php
12.40106276444111 c/r ratio
no ping
only 91 octane available here in the ca....sad...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">12:1 is doable with hondata, NOT a VAFC. you will ping, i guaruntee it.</TD></TR></TABLE>

thats crap


12.3:1 on ca gas, stock 2000 GSR ecu... NO ping


over 20k miles on the motor, runs fine to this day... 310cc injectors, FPR and FPG


i hate internet rumors.

 

no ping that you can hear. i guaruntee you it is though.

 

12:1 on 91.. tuned w/ hondata.. Dialy driven in Socal

 

12.5:1, will be daily driven, running 310 cc's, FPR and a V-afc for break-in, but eventually will get hondata.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">no ping that you can hear. i guaruntee you it is though.</TD></TR></TABLE>


no ping you can hear, no ping aem ems can pick up... but it is there...

*shrug*

to each his own, it comes down to tuning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">
to each his own, it comes down to tuning.
</TD></TR></TABLE>

 

you dont have to change them but you should if you want the motor to last

 

Have you guys checked out the latest issue of import tuner to see what some of the top engine builders in the industry say about what compression ratio is streetable on 91 octane? Read it and tell me what you think then.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">no ping you can hear, no ping aem ems can pick up... but it is there...

*shrug*

to each his own, it comes down to tuning.</TD></TR></TABLE>

You do know that engine ping is only metered by sonic frequencies right? If the EMS doesnt pick up the frequencies, it doesnt mean its not pinging, it means the EMS isnt picking them up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by krazie1 &raquo;</TD></TR><TR><TD CLASS="quote">

maybe not that crazy but some ITR would be nice

depending where u live and the gas u can get as for us in california 91 octane doesn't let us go passed 12:1 compression ratio

but if u can get the p30 or 99-01 si pistons which will bring up to 13:5:1

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

whoa wherd u get those numbers from??

 

I dont like the ITR Pistons! CTR's are nice but you will have a really high compression and will need to really tune or you will ping! Honestly get the P30 Pistons you cant go wrong!