Ok I have a 2000 civic si which as you know comes with a b16a2. There are no problems with this motor besides it needs new rings, but my question is I know the b16a2 has a small displacement compared to the b18 series motors. Should I run a B18b ls vtec block, B18c1 gsr block, or what? I have been told several times to swithc motors and I am about to start a full blown FI build. I just want some honest opinions on the block and head to start with. Cause I know the B16a2 and b18c1 flow about the same. But all i am looking for is the block and head opinions nothing else. The setup I can figure out on my own as for the internals, turbo, etc. But I am lookin to build this motor to 350 to 400 for the first build and everyone knows it wont stop there until I cant pull anymore out of it or I can't dish out hte money to make more power lol. Thanks guys

 

If you're going with forged internals, which B18 block you choose doesn't really matter, but they have their pros and cons. LS blocks are more abundant, and easier to find cheap. The LS crank also has a longer stroke, so you gain a bit of displacement from that. The GSR blocks have piston oil squirters (which you wouldn't need with forged pistons anyway), a main girdle, and shorter stroke for a better rod/stroke ratio(if you care about that). If you can live without a main girdle, or don't mind the extra cost/work to install an aftermarket one, I would go with an LS block since they're cheap and easy to come by. If you absolutely must have an OEM girdle, then go with a GSR block, but I would consider putting an LS crank in it for some extra displacement.

The B16 PR3 head is the basis for the Type R head, which is basically a factory-ported version with bigger cams and better valvetrain. GSR heads have the smaller square-shaped combustion chambers that increase compression a little, but I'm not sure if you're specifically looking for that. Both heads flow well and respond nicely to head work. I'm not sure what kind of head work you have planned, but since you already have a PR3 head on-hand, I would just go with that and upgrade the cams/valvetrain if your budget allows for it.

 

GSR...Has the girdle , good rod stroke ratio , and a Vtec head will just bolt right up. Im running a 2ltr LvVtec turbo tho

 

personally i am not looking for a girdle, if all else fails later on i can get an aftermarket one. cause i have seen many of motors over 500hp without a girdle. it is great to help to strengthen up the bottom end but not really looking for it right now. unless i get a great deal on a gsr block. but i am starting with a completely bare block and building from the bottom up so LS block be good enough?