hey HT I'm new on here and was wondering if someone would chime in on a problem I'm having , so I built an lsvtec with forged internals , I recently took the head off and noticed scratches running down vertical on the intake side on the bore , is this a butting issue or something else ?

 

Can you feel them with your fingernail? aka Does your fingernail catch on them?

 

it looks ok. U have more play with forged internals. I hope u run a good ptw clearence and pistonring clearence

 

Ya i'd say that looks fairly normal.

 

thanks guys , I can just barely catch them with my finger and the scratches are on both intake and exhaust side of the bore . so that leads me to believe it's maybe ptw clearance but I believe if I can remember it was 35-40 thou clearance . it's going in for a hone cuz I'm going hi comp for all motor and I'll verify with the machine shop if that's normal .

 

vertical scratches like that are almost always piston to wall problems.

"35-40 thou" is .035-.040" which is way too big. Moving the decimal over one gets you where you want: .0035-.004"

 

yes thanks so it's 3 and a half to 4 thoushanths

 

 

this ptw is good!

 

Make sure you clock your rings correctly as well