[Moaus]

so after the incident i had 2 weeks ago (https://f30.bimmerpost.com/forums/sh....php?t=1776658), i'm looking into a new piston set. i saw the ones from CP-CARRILLO FORGED PISTON SET (BMW B48) - any more suggestions ?

i'm a bit confused about the bore size/compression ratio.

if i'm not mistaken stock is 82mm/11:1.

should i stick with the same size ?

options for bore size: 82mm, 82.5mm.
options for compression ratio: 11:1, 10.5:1, 10:1.

what about coating ? (skirt/dome) do i really need it? (seems like overkill).
i don't want to change anything else apart from having bm3 again on the safe side without having more issues engine wise.

btw - located in Israel so i prefer ordering from europe/asia as the shipping costs from usa are something like 130$ (the value of the product is 800$)

[SRHosein]

Originally Posted by Moaus

so after the incident i had 2 weeks ago (https://f30.bimmerpost.com/forums/sh....php?t=1776658), i'm looking into a new piston set. i saw the ones from CP-CARRILLO FORGED PISTON SET (BMW B48) - any more suggestions ?

i'm a bit confused about the bore size/compression ratio.

if i'm not mistaken stock is 82mm/11:1.

should i stick with the same size ?

options for bore size: 82mm, 82.5mm.
options for compression ratio: 11:1, 10.5:1, 10:1.

what about coating ? (skirt/dome) do i really need it? (seems like overkill).
i don't want to change anything else apart from having bm3 again on the safe side without having more issues engine wise.

btw - located in Israel so i prefer ordering from europe/asia as the shipping costs from usa are something like 130$ (the value of the product is 800$)

Sorry to hear about your car.

1. Piston Size - I would say try CP stock bore and ratio, if deviating, your stock map may not run properly and you may need to custom tune for it. I am also planning to upgrade and was looking at CP Mahle and Supertech. Supertech has best price but I was leaning towards CP. For Mahle I could not find stock piston ratio. Whoever you are doing the work with make sure they good, I have seen users getting blowby issues after replacing forged pistons and plenty oil in intake.

2. Coating - Big Boost turbo made 900+whp on b58 without any coating. However, the skirt coating maybe a good idea if your cylinder walls are worn.

[sqwinny]

You can try and stay with stock size, but then again you should hone and get piston clearance to match as much as possible. Thus talk to your machine shop and find out the bore, other pistons accordingly. You can't just eyeball it.