Hello I'm trying to learn about CR & LS VTEC setups. My question is: what are the differences between b20s and b18s (specifically LS) other than the factory bore size? Regardless, I would re-sleeve to 2.0L and run 11.5 compression. Is one or the other more beneficial? I understand that they both have 89mm stroke, so it seems to me that at 2L, they are the same.

Also, just out of curiosity, what is the safe bore limit of these (with aftermarket sleeves)? By safe I mean good to use on a roadcourse. And, any ideas on power at 2L/11.5 CPR with a completely stock ITR head w/PS, ITR trans, and a decent header/exhaust setup tuned? Thank you!!

 

b20's are pretty much a bored ls share the same non vtec p75 head stock b20 sleeves are very thin and not good for boost or hella compression have seen many stock block stock b16 head b20 vtecs put down 180hp with ebay bolt ons and a simple vafc tune

 

thanks I was thinking this but wasn't sure. B20 engines are cheap but I can get an LS block for next to nothing.

 

The B20 engine has iron sleeves that are cast as one piece, where the B18a/b sleeves are four separate sleeves. Other than that they are the same, besides displacement.

 

if ur going to build a motor then go LS if on a budget go with YCP pistons 84mm highcomp go from there if u go with a b20 u cant get 84mm piston u would have to spend more money then just gettin a LS

 

if you plan on resleeving, i would go with the ls motor. bore out to 84mm.