in general, what upgrades can you transfer from a b18 to a b20 besides for intake, exhaust, turbo?

 

External wise they are almost the same exact motors, with a bare B20 longblock you could swap over all of your B18 parts. As for internally i think thats self explanitory.

Since you mentioned turbo i would be the first to say that you would be better off staying ls-t than switching to the B20 which has weaker internals. An extra .02 liters wont make as much of a difference compared to the amount of power and boost most ls engines can handle

https://honda-tech.com/zerothread?id=1323059

 

LS's and B20's internals are all teh same except for the pistons and cylinder wall. There is no weakness in internals ove rhte LS as they are the same. It's the heavier mass of the larger bore piston that likes to pull the rod and grab the bearing and spin it under high load/ high rev. I have seen many stock B20's run great no problem on boost but I would also recommend saying LS if you plan to go boost.

It's a extra .2 literage difference.

 

8 out of 10 times your cyl walls will crack if you boost a b20. i dont care what other people say about how they seen b20's turboed and they run fine. yah maybe for that day but not very long. stick with the b18 you will be fine.