Racintweek

i know absolutley nothing about SBC's. my buddy cracked a piston in his LT-1 and it ate up the cyl wall pretty good. how much of an over bore can he do and still be safe??

linkmustang

what block is it

Racintweek

lt-1 5.7l

linkmustang

i posting it on http://www.turbomustangs.com/forums/...?s=&forumid=20

thiggyperformance

well i know on the early style blocks you can go .0060 over safe i know this because i have did it may times without over heating problems but the lt1 i am not sure of the casting but i would guess the same. manufacturers usually offer pistons in the maximum overbore

so to make a long story short see what is offered far as replacement pistons and go look at the lt1 fourms

linkmustang

"0.030 is safe.? 0.060 can be thin. Best bet is take it to a shop and have them sonic check ALL the bores. If the block has a lot of shift 0.030 may be too much. You can do a short fill in the block to to gain some strength. Or a tall fill?"

jinxy

1mm should do it 20 over stock about the same deal.

Racintweek

.020 over is .5mm, .040 is 1mm

jinxy

damn, thats what i get for working at a french canadian vehicle dealership and using nothing but hte metric system

Bone1

.030 is a standard punch out for a SBC/LT1, only ones you really have to watch is the 400's.........

You can punch the SBC .060 if needed, but core shift can bite you in the ***.