I recently bought my b20 block and crank from someone and was wondering which bore I should go with? I plan to resleeve the block during the building of the motor. Stock, 84.5mm or 85mm? It's going to be in a daily driven car so reliability is a factor. What do you people think I should go with?

 

find a good deal for pistons and whatever size they are, bore it to that.

 

I plan to stay all motor with an 11.5 compression ratio is possible. Since my car is going to be daily driven I don't want anything over 12:1. The highest gas I can get around my area is 91 oactance. I plan to get JE pistons but I don't know what size bore to get? Stock, 84.5, or 85? Anyone have any comments on this? Thanks

 

84.5. i wouldn't go 85 without resleeving.

 

I am going to resleeve my block.

 

why resleeve? if no NOS, or forced induction, should not be necessary. note that some of the CRV blocks CAME with slightly egg or ovoid cylinder bores, and so a .025 overbore recommended plus you can consider "blocking" or removing .010 from the top deck of the block to give a good planar surface.
with that, no sleeving usu. thought necessary (an cheaper) - of course dep on application and betterskip the NOS.........hope that helps.

 

84mm is OEM

 

If your definately resleeving than go with the biggest bore you can get. With GE sleeves you could probably run 85.5mm, and still have up to another 1mm left in case anything ever happens to your motor. You could get some custom Ross or JE pistons for almost nothing more than stock size pistons. I think you can get Ross pistons, pretty much any size with rings and pins for $550 but you need to have all the measurements for the piston.

With an ls crank, and 85.5mm, your motor would displace 2043cc's. If you ever want to run nitous or boost, I would go with 84.5mm at the most. That would be 1996cc's of displacement. Good luck with whatever you choose.

 

Well heres the thing, the person I bought the block from said that he is selling it because the car over heated. Would that warp the block? Since the block isn't at a tip top shape I decieded to resleeve it for more strength. I also bought the b20 crank with it. I plan to get my motor built by importbuilders but I am going to be buying most of the parts myself due the fact that I can get parts for less. With an 85mm bore and b20 crank what would my displacement be? I want to stay all motor for right now, need the motor to be as reliable as possible since it is going to be my daily driver, and redline to be around 8500rpm or higher if I can bigger cams in the future.