b20/vtec piston myth!!!!!!
 

ok ive built ls/vtecs. and now its time to do a b20b/vtec. ive searched everywhere and half the people say the pistons wont clear the valves and the other half say they will. i kinda dont wanna experiment and break something. can someone help me.

Re: b20/vtec piston myth!!!!!! (crazi92hb)
 

its the same as a lsvtec ..needa enlarge the valve releifs i beleive..

Re: b20/vtec piston myth!!!!!! (GOLDBERG)
 

I agree, the VTEC valves are larger diameter and wil pWn the piston. https://honda-tech.com/forums/images...s/emsmilep.gif

Yeah, the valve relief on the B20B pistons aren't big enough to accomodate the VTEC head valves. You can either take it to a machine shop, get new pistons or perhaps adjust the valves.

Re: (RudeBwaiSi)
 

see its confussing me cuz i heard one of my boys sayin he didnt touch them. but another one did and his car blew up like 3 months after he shaved the pistons. but i was just lookin for somone who had done it and had a reliable motor.

Re: (crazi92hb)
 

If you use anything cams CTR and smaller and don't rev too much over 8k, you are usually fine.

If you use bigger cams or want to rev higher, then you need to notch the valve reliefs... there's a thread about how to do this w/ a grinder and some duct tape (not pretty but it works).

Re: (crazi92hb)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crazi92hb &raquo;</TD></TR><TR><TD CLASS="quote">see its confussing me cuz i heard one of my boys sayin he didnt touch them. but another one did and his car blew up like 3 months after he shaved the pistons. but i was just lookin for somone who had done it and had a reliable motor.</TD></TR></TABLE>

seriously..look at my sig..kinda just like this..if u wanna listen to your "boy" then go ahead..but dont post asking if its ok or not and then u get the dorrect answer and start trying to debate it..... just use the stock b20 pistons with some high lift cams..fun times https://honda-tech.com/forums/images/smilies/emthup.gif https://honda-tech.com/forums/images...s/emsmilep.gif

Re: (GOLDBERG)
 

i run ctr cams. in my b20 with z piston untouched.rev to 8500.never had a problem.

Re: (crazi92hb)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crazi92hb &raquo;</TD></TR><TR><TD CLASS="quote">see its confussing me cuz i heard one of my boys sayin he didnt touch them. but another one did and his car blew up like 3 months after he shaved the pistons. but i was just lookin for somone who had done it and had a reliable motor.</TD></TR></TABLE>You want it reliable I see, and not blowing up in 3 months. I suggest changing the pistons, or machining the valve reliefs. Just to be on the safe side, some might leave it and be ok. . .some might have problems. But I don't think those who "do it right" have any problems. I am doing this build and trying to do it right, only thing I am using from the B20 is basically the crank. https://honda-tech.com/forums/images/smilies/emthup.gif

Re: (RudeBwaiSi)
 

I got this crazy idea....why dont you just clay the motor first. If you have clearance go for it, if you dont install new slugs.

Re: (97L-esVeeTeg)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97L-esVeeTeg &raquo;</TD></TR><TR><TD CLASS="quote">I got this crazy idea....why dont you just clay the motor first. If you have clearance go for it, if you dont install new slugs.</TD></TR></TABLE>

changing the pistons to what??

I'm about to take on a B20/Vtec porject of my own and I need this info also..

Re: (DxBurnoutKing)
 

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

changing the pistons to what??

I'm about to take on a B20/Vtec porject of my own and I need this info also..

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

aftermarket forged pistons

Re: (SilverCIVIC96)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SilverCIVIC96 &raquo;</TD></TR><TR><TD CLASS="quote">If you use anything cams CTR and smaller and don't rev too much over 8k, you are usually fine.

If you use bigger cams or want to rev higher, then you need to notch the valve reliefs... there's a thread about how to do this w/ a grinder and some duct tape (not pretty but it works).

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

Yup, I have the pictures if anyone wants me to put them up. If I don't still have them on my photobucket account I will have to load them up next week and put them up.

With the JUN 3's the valves weren't hitting a lot but any contact at all is not good so I busted out the good ol dremel and took care of business.

*This was a freinds motor I was helping and not mine just for clarification.

Re: (EKhatch)
 

I daily drive a stock bottom end b20z/vtec and after 3300 miles of daily driving and it seeing 8k every day, not a problem at all. Im not sure if there is a difference in valve relief size on the b/z pistons, but mine have absoluetly no problems at all. I over revved it one time to 9k and still no problem. https://honda-tech.com/forums/images/smilies/emthup.gif

Re: (B18TurboEF)
 

you can run any cam up to about a ctr cam as long as you leave the cams near 0, 0. you will only have about 1 deg of movement on each cam before shit gets too close. as long as you have good valve train revs wont be a problem.

Re: (B18TurboEF)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18TurboEF &raquo;</TD></TR><TR><TD CLASS="quote">I daily drive a stock bottom end b20z/vtec and after 3300 miles of daily driving and it seeing 8k every day, not a problem at all. Im not sure if there is a difference in valve relief size on the b/z pistons, but mine have absoluetly no problems at all. I over revved it one time to 9k and still no problem. https://honda-tech.com/forums/images/smilies/emthup.gif </TD></TR></TABLE>

For the sake of the origninal poster what cams are you running? Stock?

Re: (EKhatch)
 

as of now yes they are stock b16 cams

Re: (B18TurboEF)
 

I built a stock b20vtec with ctr cams for my friend 3 weeks ago. I had no problem with valve relief clearance. The block was b20b and gsr head. The ctr cams will clear as long as you don't touch the cam gears (0,0).

Re: (porsche997dc2)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by porsche997dc2 &raquo;</TD></TR><TR><TD CLASS="quote">I built a stock b20vtec with ctr cams for my friend 3 weeks ago. I had no problem with valve relief clearance. The block was b20b and gsr head. The ctr cams will clear as long as you don't touch the cam gears (0,0). </TD></TR></TABLE>

I want to do the exact same thing... except with ITR cams... will i be ok with the OEM pistons? or would i need to get something else?

I saw a thread with Wiseco Pistons... would those work in my favor??

https://honda-tech.com/forums/images/smilies/emthup.gif

Re: (DxBurnoutKing)
 

I have the same question I have a B20B block and I want to go vtec with a B16 head I dont want it build to race, just something reliable. https://honda-tech.com/forums/images...es/emdgust.gif

Re: (SinCitiEK4)
 

Well choose one of the answers above. If you want it reliable, spend the extra money and/or effort to make sure you don't have to question if a valve is hitting a piston.

Re: (RudeBwaiSi)
 

i just got done tuning a B20/VTEC motor with the stock bottom end and a B16 head. the guy didnt noch the pistons and there was no valve to piston contact. he was running SKUNK2 STAGE 2 cams!!!! i didnt wanna rev the motor too high (only to 8K) and left the cam gears set at 0,0

Re: (boosted k20)
 

will the ctr or itr cams work in stock block ls vtec w/ b16 head? Do I need valve springs and retainers. Sorry not trying to post whore just wanna know.

Re: (hondaluva)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondaluva &raquo;</TD></TR><TR><TD CLASS="quote">will the ctr or itr cams work in stock block ls vtec w/ b16 head? Do I need valve springs and retainers. Sorry not trying to post whore just wanna know.</TD></TR></TABLE>


yes. valve needed if you want to rev past 8k.

Re: (Phatch99)
 

So would be safe to say its a good idea to re-sleeve the block? https://honda-tech.com/forums/images...es/emdgust.gif