pistons

[overboosted1g]

so i spun a rod bearing on my motor and need to bore over my cylinder walls because they aren't in the greatest shape and i found a set of .40 over pistons is .40 too much

 

[drewboi]

thats kind of big... have a machine shop or someone that knows what their looking at check your block out.

 

[overboosted1g]

the machine shop said a minimum of .30 over needed to be done but i found a set of topline 8.5:1 pistons but their .40 over

 

[Barlow]

Should be fine.
I believe oem pistons are sold up until .60 over. But most people would only start with .20 becouse they would still have some cly. wall left in case they need to go larger in the future and then they wouldn't need to source out a new block.

 

[boosted_ego6985]

.40 over is not too big but however it is a lil harder to find those pistons and rings in stock almost anywhere for performance pistons. You would be better to do .20 over as most performance places will have these in stock and not to mention be a little bit cheaper. You should do as mentioned and have a machine shop to look at your block to see if it indeed needs to bored out or if it just needs a good honing to smooth it all out again. Good luck with it.

 

[RadDsm]

.040 is fine.
I'd use NPR pistons before I'd ever use Topline.

 

[TofastForU_99]

"Turbo lag is just their to give v8s a chance" Im pretty sure its "there" not their... Regardless of which there you used I would reword your sig. It doesn't sound right at all. just messin with ya.

NPR pistons are like 100 bucks with rings on ebay... I haven't had a problem with them on the stock rebuilds I do.

 

[TSIfreek]

The more your take off the block bore for machining the weaker the walls/block get. The best thing to do is start off as small as possible like 20 over. Take the block to your machineist and see what he wants to do as he will give you your best answer. I would not buy pistons if your unsure how bad the block is.