Oversize bore??????

[1997_GSX_mar]

i need help finding out which bore size is better .020 or .040?

 

[94MightyMax]

For what purpose? Smallest you can go the better. If your just rebuilding it and a hone wont do but you can get away with .020 then thats what you want. The bigger you go the better chance you have of overheating or cracking a cylinder under pressure. And if you go to .020 now and want to rebuild it again down the road you can go to .030 or .040 later instead of needed a new block, or resleeve

 

[Anger890]

The 63 block has very stout walls, people have bored them 0.060"-0.080" or 86.5-87mm. I would go with the smallest overbore that wouold clean up the bores. (most likely .020" over)

 

[thatblondechik]

Cylinder bore on a 4g63 isn't the same as say a Chevy 350. Power isn't made from honing out the walls. Take Shep for example, he's well into the 7's and what's he got? 2.0.

Just go as small as you can.

 

[95eclipser]

i say go .20 over bro.. the smaller the better +1
if you mess up your block in the future you can bore it out .30-.40 and not need a new block

good luck man

 

[stevestevesteve]

i say bore it over till there are no cyliner walls left ;] then you dont have to worry about it cracking just have 1 big piston.....

just kidding go .02 over

 

[thatblondechik]

i say bore it over till there are no cyliner walls left ;] then you dont have to worry about it cracking just have 1 big piston.....

2.5" over FTW!

 

[woodnbronze24]

20 seems like the way to go

 

[canada4g63]

if you didn't score the cylinder walls then i'd stay stock bore.