hello everyone. I am going to be running a stock b20z block with an oem headgasket and a gsr head. (not milled). i am also gonna be running s2s2 cams. my question is will i need to cut the valve reliefs? some people say you do and some say you dont. i have searched and some people said you only have to cut if its a b20b block. Can somebody enlighten me? anyone done this setup?

 

i've tuned a stock bottom end B20Z with a B16 head run n S2S2 cams with no problems. the valve reliefs in the pistons were not cut. the motor was only revved to 8K. car made 186whp on the stock bottom end

 

thats sounds good. but will i need to cut them for my gsr head?

 

I have to suggest investing in new pistons instead of cutting the stock ones. From what I've experienced with CRVTEC setups you will have clearance issues.

 

thanks for the advice anybody else?

 

Agree with Kendall.

 

bump

 

the only way to know if youl have clearance problems is to clay your motor even if someone with an identical setup isnt having problems that doesnt mean that you wont id agree with the guys that said invest in better pistons but if you clay your motor you will be fine

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">I have to suggest investing in new pistons instead of cutting the stock ones. From what I've experienced with CRVTEC setups you will have clearance issues.</TD></TR></TABLE>

We'll see what omniman has to say about this ...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LG_R32 &raquo;</TD></TR><TR><TD CLASS="quote">the only way to know if youl have clearance problems is to clay your motor even if someone with an identical setup isnt having problems that doesnt mean that you wont id agree with the guys that said invest in better pistons but if you clay your motor you will be fine </TD></TR></TABLE>this is the right way of doing things, if you have the available resources!
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">i've tuned a stock bottom end B20Z with a B16 head run n S2S2 cams with no problems. the valve reliefs in the pistons were not cut. the motor was only revved to 8K. car made 186whp on the stock bottom end</TD></TR></TABLE>you won't have anyproblems with the b16, but the man is running a gsr head!
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AllM0tadc2 &raquo;</TD></TR><TR><TD CLASS="quote">hello everyone. I am going to be running a stock b20z block with an oem headgasket and a gsr head. (not milled). i am also gonna be running s2s2 cams. my question is will i need to cut the valve reliefs? some people say you do and some say you dont. i have searched and some people said you only have to cut if its a b20b block. Can somebody enlighten me? anyone done this setup?</TD></TR></TABLE>the b20b block is the one, that will give you the most room to play with when it comes to choosing head and cams combo. the reason for this is because of it's lower C/R, compared to the b20z is close to a point in compression difference! so you will have to cut the reliefs on your b20z bottomend, without this you could do severe damage to the engine!
i have a totally stock b20z bottomend, with a itr head and BC4 cams! i didn't have the time to clay the motor, so i took a vtec valve and measure the difference on the piston. i cut open the piston so that i would accomodate the larger valve, as well a digging out some material off the piston to reduce the chance of the valve hitting the piston! with vtec locked in on the #1 cyl, a single spring set up on the exhaust and intake side. i recorded no valvetrain interferience, up to 6+&- on the cam gears with the bc4 cams! not the best way to do it, but it gives you an idea! good luck

 

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

We'll see what omniman has to say about this ... </TD></TR></TABLE>

i don't know him personally, but, i can bet that he'd say there will be clearance issue is other measures aren't taken to prevent it (most notably, enlarging the piston valve reliefs). Omni's buld is not an untouched oem b20b/z shortblock. from what i know, anything bigger than itrs in a unmilled pr3 head with no cam gear adjustments is close to the limit on most b20b/z shortblocks. one might be able to get away with ctrs and a p72 head, but, i wouldn't try it.

 

yes, you need to cut the valve reliefs, /thread

 

bump