How Much Oversize Can U Go

[Strik3r]

Helllo

so there are a few people who know my story, but to sum it up, i have an N1 block thats already at 87mm bore size (40 thou over). There is some damage to cylinder 1 and to reuse it, it would require re-boreing it out to 87.5 (60thou over). Ive been told by some people that this is a big no go, as the block gets too hot under load and will crack, however i've also been told that the HKS / Tomei stroker kits specify an 88mm bore to be used (80 thou over).

Does anybody have any experience with boring out an N1 rb26 to this size ? Keep in mind, this will be used for a fair bit of track work. Any comments/feedback ?

[-_-StRyDeR-_-]

if its going to be lent on hard then i probable wouldnt... but thats just personal preference.

[dmac_25]

Helllo

so there are a few people who know my story, but to sum it up, i have an N1 block thats already at 87mm bore size (40 thou over). There is some damage to cylinder 1 and to reuse it, it would require re-boreing it out to 87.5 (60thou over). Ive been told by some people that this is a big no go, as the block gets too hot under load and will crack, however i've also been told that the HKS / Tomei stroker kits specify an 88mm bore to be used (80 thou over).

Does anybody have any experience with boring out an N1 rb26 to this size ? Keep in mind, this will be used for a fair bit of track work. Any comments/feedback ?

You have 2 options keep the 87mm bore size on 5 pistons bore out no1 to 88mm and sleve it down to 87 or bore them all out to 88mm and sleve them down to 86mm or 86.5mm

[SKiT_R31]

how much damage? you might be able to get away with just honing it

[johnbarry88]

too far 40thou is pretty much the limit start cracking cylinder walls with big power after that..