okay i have a 91' ls and im about to redo the vaulves but my friend suggusted that i should take it to his mechanic and have them bore it .60mm over and drop in some new weisco pistions and do a whole new head and i got to thinking its not a bad idea im getting horsepower increase and the enging is going to be underwarranty and also it saves me time from having to do it. so i just wanted to know if any one knows what a job like this would cost and if someone could tell me some performance numbers i might expect to see in HP.

 

There's no reason to. You won't really gain much at all, it's not worth the $ in my opinion. Plus, you'd have to buy new rings, bearings, rods, etc...not just the pistons. You might gain a couple hp...but that's about it. Replacing pistons is more about strengthening the bottom end for boost/nitrous/high compression/high rpm.

 

werd. only do it if you plan on boosting or something later. and only do it if you really plan on keepin the car.

 

If you do a 60mm bore, you best be going NA...
"they" say the safest diameter to bore to = 45ish...
and at 45 (2liter) is even a minor difference...
i'd only bother to bore if i was going to resleeve as well, and push high ass boost... high enough where the displacement will make a difference.

 

You are way wrong. You're thinking 86mm bore, and 84.5mm bore. He's talking about going 81.6mm bore, which nobody even makes pistons for. They do however make OEM pistons for a .25mm overbore, and anything more than that I'd probably want to resleeve.

 

ah yes, sorry... haha, i had just woken up, and had my numbers mixed up... but yeah, what dubcac said...
sorry for the mix up... forgive me? :kiss: :boink:

 

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