Guys, after doing some research i got really confused. im like totally lost dont know what to do now. My plan was to build B20z with GSR(p72) head and GSR tranny. But did some research and found out that b18b block is better due to rev limits or some **** like that. Im fairly new to honda game and i dont know that much. i know fairly enough but still wanna ask u guys with experience. What should i do now just get the GSR head and slap that on b18b1 block or still get the b20z block? BTW its going into DC4. Please be specific. Thank you!

 

I can't say much about a b20. But what i can say is yes, the B18 does rev OK for an LS-V . Here's the deal though, it really depends on how much you are planning on putting into the lower end as to how much either motor will rev. neither motor is built to rev very high, thus neither were intended to be mated to a vtec head in the first place. I won't get into all that but I will say this, at the MINIMUM, you need arp rod bolts, and a block guard to rev SAFELY to 8500 rpms. Though rpm's are a good thing for honda power, the reason for building an LS or B20 vtec is for the torque. If you aren't interested in that then i'd get a gsr bottom end and run that..

 

The b20 and b18a/b are basically the same block except the b20 is 84mm bore. Im almost positive that share the same crank and rods (correct me if im wrong).
Ive always heard about the rumor of the b20 having weak cyl. walls but if you build it right, it will run right.

 

B18 or b20 , same everything minus bore as stated above. 81mm vs 84mm.

Both will have same issues, meaning if you build bottom end sloppy wont matter if its b18 or b20.

Go with what you prefer. More people go the B18 route because they can reuse the pistons of the block they took the head off ( most of the times unless you need to bore the more a little to accomodate defects in the cylender walls ). And B18s are much more available.

So to sum it up. Dont worry , go with wich ever you want. and Can find.

Just remember to measure all the clearences and rev till you make power ( most motors around 8000-8200 unless you have a nice set of upgrade cams, in wich case up to you and tuner where your rev limit is.