how much power is gained by boring .020 over?

natt2000

New Member
if i were to bore my b18a1 20 over, does anyone have an estimate of how much power would be gained?
 

Samurai_Blue

Yolo Whippin'
not at all it just raises compression ever so slightly

wait so you are going to bore .02mm over??????
 


mirrorimg

Well-Known Member
Its .02 inches which is about 5mm. This means the block is going from 81mm pistons to 81.5mm pistons.

You wont notice much, as more of the gain is going to come from bigger cams and higher compression pistons. Since you will have to get pistons if you bore the block out larger (why not just go to the serviceable limit of the block, with is 82mm? (.040")) you can get some RS Machine ITR or CTR style pistons.
 

fodo91ls

New Member
Just get a b20. Build it up. And slap it in when you're done. If you're dead set on not having v-takk yo.
 


Samurai_Blue

Yolo Whippin'
mirrorimg said:
Its .02 inches which is about 5mm. This means the block is going from 81mm pistons to 81.5mm pistons.

You wont notice much, as more of the gain is going to come from bigger cams and higher compression pistons. Since you will have to get pistons if you bore the block out larger (why not just go to the serviceable limit of the block, with is 82mm? (.040")) you can get some RS Machine ITR or CTR style pistons.
Click to expand...
RS machine is now strictly an ebay only shop. tried to call them twice and a few emails. the CTR dome will kill the ls head.
 

Samurai_Blue

Yolo Whippin'
with the a1/b1 the biggest piston you can run without modification to the rod is the b16 piston, the ITR , ctr and gsr pistons need the rod to be milled 1mm on each side. the b16b piston is too domed for the ls head. you will most likely have IN stamped on your combustion chamber after use.
 
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