I am using a 12.5 compression 81mm Wiseco Piston in a all motor GSR shortblock I am building. I was doing the piston to ring endgap and I got

Top Ring: .014
Bottom Ring: .024

So the bore size is 3.189 and it recommends to multiply that by .0045 for the top and .0050 for the bottom which gets me the clearance of ..014 for the top rin and .016 for the bottom ring.

The bottom ring is not even close to being anywhere near that.

Factory OEM GSR Specs, OEM Pistons.
Top ring - .20mm - .35mm (.008" - .014")
2nd ring - .40mm - .55mm (.016" - .022")


opinions?



Modified by BodyKits NW at 10:33 PM 5/21/2008

 

What do Wiseco specs say?

Holler!! Halo Halo and Baloot FTW.

 

The gaps are fine.

 

It is just odd cause I typically use what the mauf. recommends on all of our builds. I don't use OEM specs when it comes to the piston end gaps unless I am using cast pistons. I have always mulitplied my bore size x .050 etc.. depending on what I plan on doing. All motor, forced induction..and use that number. That bottom ring didn't even come close to the clearance I got from doing that math. Came within OEM specs, but not to what wiseco recommends.

Now just need to figure out what cams to run in this 1.8 12.5 compression beast of a motor LOL.