I was wondering which piston to chose for my ls/vtec build. I want to be somewhere between 11.5-to 11.7 c/r. My first choice was goin to be the pr3's however ive been hearing that the b series vtec heads like smaller chambers. So basically i was thinkin about milling the head .03 and buying some flat bottom valves. Which now brings my to the point of cutting bigger valve reliefs. Im now thinking about going with a slighty flatter piston as oppesed to the pr3's also because of better flow in the camber (something along the lines of either usdm of jdm p73's). I tried to contact omniman for his help but failed becuase this is pretty close to his b16 build. Anyone of your suggestions will be greatly appreciated. Thanks alot and sorry for the long post.

 

p30 (jdm 16)...gives 11.5ish:1 perfect if you ask me

and i may be selling a set....

 

p30's or pr3 ive used these pistons in two build one with gsr head p30's and pr3's with gsr head trust me itll put a smile on your face!
if you get a gsr head with p30's 11.8.1 and pr3's is 11.5.1 with gsr head.

 

awesome thanks guys... so im guessing you both suggest that i shouldn't mill the head? I guess that will save me some headaches with cam timing. Also i live in pennsylvania and i go to school in louisiana. I make a couple trips back home each year and was what are my best choices for cams and what intake manifold to run. Ive been doing alot of research over the past years and not enough hands on experience. If anyone has any prefernce on cams i should run thats will be reliable it would be a great help. I was thinkin along the lines of BC3+, m22, or blox b's and thinkin about running a blow manifold. Like i stated before im open to all opinions. And any other random comments, criticisms, curses that anyone has about the build please post.

 

b18 block
pr3 piston
and gsr head,

would it be a dramatic different from a b16a head wit p30?

 

here's an excellent LS/B20vtec build write-up

tons of valuable info

 

compression calc shows with pr3's and a gsr head you get 11.81:1 cr and with p30's and b16 head you get 11.54:1 which is just about the optimal straat ratio. gsr head will sit you a little high and require more tuning or possibly a bigger cam. i would go with s2s2 cams with the p30's and a b16 head. makes good power.

 

thanks guys.. i guess ill have a better idea once I pick up a head. Im sending the head out to get slighty ported and have some other small stuff so im most likely going to snag the first one i come across( whether it be a gsr or a b16).

 

p30's are your best bet