So here it is I currently have a B20 Block sleeved and im making about 550Hp at the wheels its all fine and dandy however the rings have died and there is a scratch in one of the sleeves. I am looking to see if i punch it out to a 85mm Bore is this safe or am I likely to pop head gaskets more often then not. The Block is sleeved by golden eagle and rate at high PSI no worried so much about sleeves rather then the head gaskets.HOPE YOU CAN HELP

 

From what I've gathered, I may be incorrect, but you'll have HG sealing issues at 85mm.

I might be mistaken, though.

 

Yeah I have heard the Magic number for high boost is 83mm but im trying to stay away from having it resleeved again. but if im going to run into more issues them im not sure.

 

Funny, I've heard 84mm.

:shrugs:

 

83mm ftmfw

 

So im gathering to go ahead and resleeve it and stay away from 85mm bore there was another post that was written and people have been suceddful but we all know how that goes no two motors are the same.

 

You will be fine at 85mm with as much boost as you want as long as you a tuner that has an idea.

 

Can you Elaborate on that a little for me. have you had success or just heard horror stories there alot of torque gain with this just not alot room for error before a head gasket goes.

 

As far as power gains go, i am not to sure if it will make a huge noticeable difference over persay an 84mm setup. The one thing i will tell you is that 85mm on a b series engine is not to big of a bore for boost. I have tuned alot of high hp b series engines that are 85mm and they are just fine. No issues of headgaskets or anything like you are thinking.

 

We've made 1100whp on an 85mm b series, no worries. I wouldn't go any bigger, but you'll be fine at 85mm.

 

Is there much of a HP loss of io decide to run a 83mm piston in there I ahve only ran 84 so far on all my motors. most made was 595hp on 50/50 mix of gas c16 and 92 octance pump gas mixture at 23 poubds of boost with GSR cams

 

85.mm should be fine for high boost.

 

It will be fine.