Building my b17a1

[fakk_13]

i recently perchased a b17 for my 92 gsr that has a b16 in it now. the motor is fried. i am going to rebuild it and i dont have to bore it out but i am wondering if it is worth it to bore it out now while i build the motor and put in highcomp pistons or should i just leave the bore and put highcomp pistons. so what im trying to ask is if the bore will make a significant amount of power over the stock bore? i am just planning on a small boring nothing to big. If you have any other suggestions just let me know.

 

[AHHVTEC]

i say bore it

 

[phunky.buddha]

Small amounts of boring (like .5mm) aren't really worth that much in terms of power increases. You'll gain maybe 20cc if that... do the math. If you were willing to resleeve the block and go out to something like 84mm, then you're starting to talk about a significant gain. Keep the bore as close to stock as possible, maybe .5mm more to clean it up some- then go with nice high compression pistons, good cams, and a good tune. If you want go turbo, just get lower compression (or not if you're a good tuner) forged pistons, then start playing with the boost.

 

[fakk_13]

how much more hp do you think the .5mm bore and 11 / 1 comp pistons will give me?

 

[phunky.buddha]

A general rough rule is a 4% gain for every full point increase in compression. Go with that to estimate power.