Im thinking of doing a B20 Vtec in the near future (if I ever get a job ). But anyway, Ive been doing alot of research regarding the whole swap. I know the factory crompression ratio of the CRV is 8.8:1... what I was wondering is if B-series pistons are interchangable. I was thinking of putting my P72 pistons on there with the B20 rods, but then I remembered that the B20 sits at a 2.0 while the GSR is a 1.8, will this matter?? Does the 2.0 mean that the piston are wider?? I dont beleive that they are interchangable, but I still havent really found out.

 

p27 pistons wont fit. The B20 is an 84mm bore. Also when you change the head, he compression will change. www.c-speedracing.com if you click the how to or diy or something like that, you can match different heads with blocks etc. and it will give you the compression and the displacement.

 

the b20b blocks have 8.8:1 cr, but the b20z, and some of the b20b jdm blocks have 9.6:1 (not all of the jdm ones do so don't think just cause its jdm its the better one)

using a b20z block with a vtec head will work, but the valve reliefs on the piston aren't large enough for the vtec valves, therefore will cause clearance issues if you even slightly advance or retard the timing. your best bet is to put aftermarket pistons in the b20 block, but that means you have to tear it down, so you might as well do rods too. but if you are going through all that expense, why not just sleeve an ls block to 84mm and go from there, it'll be cheaper in the end