i see sum sleeved blocks for sale and they are 86.5mm and so on and sum 85mm and 86mm. What i wana know is, is that to thin of a cylinder wall to run a high boost turbo street set-up? Im talkin about 400-470whp 20-26psi or so. With that much boost and stress, even though they are aftermarket sleeves, will they hold up for a daily driver car. If they are strong enough then i can get a crazy bore lik 86mm or so, 86.5mm maybe? On low boost that will make alot fo power way more tq than those 83mm-84mm @ same psi.

 

it all depends on what kinda numbers you want to put down.. if a motor is tuned right and can handle the boost.. then it just matters how you treat your car.. take care of your ride and it takes car of you..

 

i say stick with a 83mm bore, b/c if for say u do mess something up, u can rebore and your ready to go, u don't have to get whole new sleeves. also, with a little bit thicker sleeve, your a lot safer running high boost. if u wanted to do something "nutty" then just run higher compression pistons. that will give u more power instead of boring it to an unsafe size. u just have to make sure its tuned right. but really, with a 83mm bore...sc61 ..9:1 c/r...and 26psi, u will make a little over 500whp.