ok I dropped a valve couple months ago, but before I bought pistons, I took the block to the machine shop to see if the block can be bored out to 85.5mm, it was at 85mm, so i had it bored without the pistons, it cleaned up all the nicks and dings, now my question is, am I going to problems if i bought CP pistons with the bore size at 85.5mm will the clearance be a problem or will i be ok?

 

errr....what motor is this your talking about?

 

Sorry it's a sleeved gsr block.

 

jus make sure you have the correct head gasket and the combustion bowl in the head match the block (while porting, usualy they ask you what size the bore is.)

 

I'm talking about the piston spec, before you bore out the block you have to have the piston first, depending of what piston you get right? I heard that CP pistons you dont have to have the pistons on hand when you bore out your block is that true?

 

no machine shop should ever bore out a motor without the pistons being there.

 

not always the case! got some info, the machine shop will bore a block whatever size you want it, all depends what piston you use, some pistons like CP and Arias include the wall clearances and some like JE and Wiseco do not, these are the one that the machine shop needs before they bore. and yes it is always better to have the pistons on hand, but in some cases the block gets dings from a droped valve and you just want to check if the block can be saved before you order any pistons.

 

Both are correct.
I believe you just need to make sure that your clearance is still with in spec.