Hi folks,

I'm sorry for my english, I'm from Ukraine

Explaine me please one thing: if I change my stock pistons to forged pistons do I need for sure an overbore? Seller of aftermarket parts advises me the pistons 96mm instead 95,5 mm stock and advises me a little overbore 0,02 ".

I didn't have such experience but my engine is in very good conditions. So I doubt... Take 96mm forged pistons or stock size forged pistons?

Give me please any advise. Thanks

Alex

 

I had my engine from another car rebuilt for racing purpose once in the past. However, that didn't turn out good. It's a long story and the end is my built engine was broken after 5000 miles. In your case, my opinion is if the cylinders are still smooth like a mirror with no scratches, you won't need to bore them. Technically, cylinders were coated with a very thin layer of special metalized material. When you bore the cylinder surface, that coated layer either get wiped out or thinned. That's why overbored/overhauled engines usually don't last as long as OEM engines.

To summarize what I said, inspect the cylinders carefully to see if they are in near perfect condition. Only overbore the cylinders If there are scratches or damage on them.

 

Thanks, I'll follow your advise

My cylinders are OK so I'll use standart size pistons without overbore.

 

I don't see the need to overbore if you have the choice to go with stock size pistons.

 

agreed with Q8y_drifter.
you have the option to go with the forged pistons at stock size. so why not just do that.

 

GTM has advised me to use 96mm pistons with a small overbore but after your questions (and on other forums) I've decieded to use standart size pistons.

The question was if I need overbore in general? Most people doesn't advise me to overbore so I've choosen standart size forged pistons.