How to fix mild pre-detonation on forged pistons.

The subject pistons are Wiseco pn 6595M85
+14 cc dish pistons w/ H.D wrist pins
03-07 Evo VIII

The pistons came into my shop with slight damage around the thin wall of the eyebrow on the outer edge.
They were hung on Eagle rods.
To me it looked like hot spotting and pre-det.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3935.jpg

Notice the damage on the outer edge of the piston?

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3938.jpg

the first step is to remove the piston from the rod.
That is done by removing the C clips from the wrist pin bores.
Be careful not to bend or deform the clips, or you will have to order a new set form the piston manufacture.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3939.jpg

Next is to mic the piston to make sure it is within spec.
http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3940.jpg

Next using a small burr I ground away the damaged aluminum

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3941.jpg

After that I used a flapper wheel to smooth any rough spots and to remove the galling

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3943.jpg

I also removed the sharp edges (90*) that was from the machining of the piston when it was first made to help eliminate and more hot spots.

Next the pistons were glass beaded clean.
http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3945.jpg

Now to maintain balance, the piston were weight matched within .2 grams
http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3946.jpg

Next I checked the balance on the rods, starting with the small end.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3947.jpg

After all the small ends were matched.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3948.jpg

I balanced the overall weight of the rod, also keeping the balance with in .2g .

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3949.jpg

Now it was time to hang the pistons on the rods.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3950.jpg

I start by installing one of the clips in each piston.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3951.jpg

After that is done, I oil the wrist pin bores in the piston.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3953.jpg
Also oiling the small end of the rod.
http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3955.jpg

Then oiling the wrist pin
http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3954.jpg.

Then sliding the wrist pin through the piston and rod, Making sure the piston faces the proper way on the rod.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3956.jpg

The last step is to install the other wrist pin clip and making sure that all clips are seated in their grooves and the rod floats smoothly on the wrist pin.

http://i261.photobucket.com/albums/ii49/BogusSVO/How%20to/DSCF3957.jpg

I'm sure it is important, so heres the question. Where do you remove the weight from on each part.

keep in mind we are working in gram weights..... on the small end of the rod, it gets "polished" off around the wrist pin bore...the big end.. off the bottom of the rod cap
piston from the bottom of the piston, some shops will use a drill on the underside of the dome, I tend to remove weight from under the wrist pin bores