Question about Wiseco Kit

[nitekrawler]

I found some kits "ATC250R WISECO +.020 OVER PISTON KIT-NEW " the .020 over is from redoing the head right? Am I on the right track? I assume, I wait to order until the machine shop tells me how much "over" they did the head right? Can someone explain how it works. :)

[whiteman350x]

The "over" is not from redoing the head. It is how much the cylinder has been bored. The oversized piston has a greater diameter than stock.

[nitekrawler]

Why do you bore it? Does that remove the scuff marks, etc. Of course I am saying in my words :)

[smokinwrench]

Yes to remove any imperfections in the cylinder wall and to also restore the cylinder to a perfect circle. They cylinder will usually get oval shape as it wears.

Yes the machine shop will be able to tell you how much it needs bored then you order the correct piston. At least thats how my machine shop operates.

[smokeyhonda]

You bore it because the guy at the machine shop says so. Really its due to wear by the piston making the cylinder bigger and probobly not round any more, a nice clean punch thru and its like new only bigger. Now it's time for a bigger piston. I understand you should have the machine work done first, then get your piston based on what the shop tells you to get. hope that helped.

[smokeyhonda]

Maybe I should change my name to IMA SLOTYPER

[whiteman350x]

You need to get the shop guys to tell you what size to get, get it, then have them bore it to match the piston. They need to have the pistion in hand so they can measure it an do an exact job.

[Billy Golightly]

yeah, don't go ordering a piston without knowing what size you'll need. For all you know the cylinder could already have been bored several times before and is already way past .020 over.

[nitekrawler]

Thanks guys