Ok guys my block had damage on one cylinder , its at the machine shop today but I need to know what's the biggest bore I can go on my 81 mm wesico pistons My setup is b16a2 9:1 wesico pistons 81 mm, eagle rods. They are going to call me later today to let me know how much they have to bore to get rid of the scatch on the wall 81.25 ? 81.50? 82?

 

well normally 81.5 mm you will have more options on piston choice/compression.

If its more then 81.5 then you might be in some trouble. i wouldnt recommend going over that on a stock block with boost.

What were youre power goals?...using pump gas?

 

I already have pistons weisco 9:1 compression

 

Im confused... If you have 9:1 81mm pistons and they need to bore it to 81.25 or 81.5mm to get rid of the scratch then you will need new pistons.

 

I still say this is a trick question.

 

If you already have 81mm pistons, then the bore size can only be 81mm.

If you go to 81.5mm you need 81.5mm pistons.

The most they can do and use 81mm pistons is hone the cylinders, not bore them.

They can hone it to about .065 ptw clearance before you start to get noisey piston slap.

 

Because it is I wouldnt expect this from an 02er

 

lol.

If a hone doesn't take it out, you're going to need new pistons

 

Just spin the pistons 360* and put them back in. It will be fine...

Heat them up with a torch to get the measurements needed, then hurry up and install them...

In all seriousness, are you serious OP?

Let's start from scratch: What exactly happened that you came to the conclusion you had bottom end problems?

 

 

I was asking what happened... as in - is he sure the pistons can even be used again anyways...

 

That's what happened. The cylinder wall got scored with something. So now he's getting it bored out. There were problems with the pistons too.

 

Well he sure seemed like they could be used again. I am just trying to push the clueless in the right direction. You can visibly see that gouge in the poor picture and most likely it is going to either be a goner or at least an 82mm bore. I assumed you were posting a random picture, I didn't know you were personal friends with him or whatever the situation is. OP - Just be prepared for a lot more money to be spent either way.

 

Not personal friends. Just a matter of looking at his post history. I don't even know why he's asking until he hears back from the machine shop.

 

If you're going to re-use your 81mm pistons, the biggest bore you can go is 81mm (plus the recommended p/w clearance)....that shouldnt come as a surprise